Haynes Mazda RX2 Owners Workshop Manual 0856960098, 9780856960093

Citation preview

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2

APPROVED AND RECOMMENDED

2292cc nominal capacity: Twin-rotary Wankel

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Ue Sg

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Wal: ISS

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(QHAYNES'

Covers saloon and coupe = 1971 onwards

Owner’s Workshop Manual by J.H. Haynes

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ay. os f:

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a.

+>

J

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iy

ee

c %

yore ee | FUEL VAPOUR —-—+> VENTILATING

OlL SEPARATOR

AIR

SEN FRESH AIR, FUEL VAPOUR AND BLOW - BY GAS Ve

LcHECK VALVE

ft

t

he

Fig. 3.9. The crankcase ventilation and fuel evaporation

control system

TANK

t

f

TANK

Chapter 3/Fuel system and carburettor:

Exhaust and emission control

Valve

To intake

crankcase

manifold

Normal operation

Not running or backfire

ie

(Road load)

Fig. 3.10. The ventilation valve in the shut position, as when not

Fig. 3.11. The ventilation valve on the taper, as for normal running

running, or after a backfire

will

burn

to carbon

dioxide, and the hydrocarbons

remaining only partly burned, can be burned direct into carbon dioxide. Because of the combustion conditions being cool, very

little of the oxides of nitrogen are formed. (NOx). 2 A pump is driven by a ‘V’ belt from the front of the engine. This supplies air to be injected into the exhaust ports. The injectors blow from below into the tract at the bottom right side of the rotor casings where the exhaust gas passes from the actual port out to what would normally be the exhaust manifold. The air to the injectors is fed into a passage high up in the centre housing from the inlet manifold casting. It has its own separate passage in the inlet manifold, and this is controlled by the “‘air control valve’’. 3 The air contro! valve distributes the air from the pump three ways. The main route is to the injectors. Another feed goes to the outside jacket of the thermal

reactor to cool it, and thence

down a pipe alongside the exhaust pipe. Excess air is blown off through a safety valve. The air control valve is on the right side of the inlet manifold, straight down from the carburettor. At engine speeds up to 4,000 rpm the valve feeds the air to the injectors. Above 4,000 rpm the control unit switches on the solenoid, which cuts off the depression from the diaphragm controlling the valve, so that its spring closes, cutting off air to the injectors, and feeding it instead to the reactor cooling jacket. When deaccelerating below 4,000 rpm, the ‘coast valve’ cuts the depression from the air control valve’s diaphragm, so the same distribution of air occurs. In the disc of the valve, the air cut valve, is a relief valve, so that some air, that in excess that can get to the injectors, always goes to the reactor cooling jacket. 4 The trailing ignition is cut at medium speeds and medium loads and when the engine is hot, so that the gasses going to the reactor are combustible. The signals for the control unit are engine rpm, from the ignition, engine temperature, from a sender

unit, and load by a switch in the vacuum ignition advance unit in

the leading distributor. 5 During deacceleration the throttle being shut, the engine canin much

mixture,

so combustion

is bad and exhaust

emissions high. In extreme cases, afterburn occurs. There are two valves concerned with this. The ‘anti afterburn valve’ is bought in by the control unit above 4,000 rpm by its solenoid being switched OFF. When there is great depression in the inlet manifold, this works on the diaphragm of the anti-afterburn valve, which opens to allow air to be drawn in from the air cleaner.

Erom

es

manifold

not draw

Spring

To intake

«=

monoxide

63

However

the diaphragm either side of the diaphragm

is

equalised, and the valve shuts again. As the valve opens when current to its solenoid is switched off, it will be activated when

the ignition is switched off, so allowing air in to weaken the mixture to stop the engine without afterburn. The coasting valve is activated by its solenoid above 1,200 rpm. Again, high manifold depression on over-run works on a diaphragm to allow air into the manifold. The coasting valve is also used to control two other functions.

It controls

the throttle positioner, so that the

throttle is held slightly open, to prevent too great a manifold depression, and it controls the depression pipe for the air control valve as previously mentioned. The coasting valve is on the extreme right side of the carburettor, and can be recognised by its connections to the air control valve below, and the throttle positioner. The anti-afterburn valve is just behind the air control

valve, and is recognisable by the large flat cover on its diaphragm. 6 To the rear of the carburettor is a smaller valve, the air supply valve. This valve is held shut by a solenoid which is live whenever the ignition is on. As soon as it is switched off the valve allows in air from the air cleaner direct to the manifold to help stop the engine. 7 There is a non return valve where the cooling air enters the reactor jacket. There is also another on the air control valve feed to the injectors, to cut off blow back pressure.

14 Emissions contro! system: general checks 1 It is part of the 12,000 miles task to check the function of the equipment. 2 There is so much interaction of the various valves that there can be no simple short cut to their check, or to tracing a defect. If the whole system is not working then poor idling, rough running with poor response, and probably high engine wear, will result.

3 Thorough knowledge of the system, and good test equipment is needed to check it. 4 This is one of the times when a properly equipped Mazda agent, with factory trained mechanics, should be got to do the job.

5 Another factor must be born in mind. The emissions control equipment is subject to legal regulations, varying locally, regarding correct function, and tampering with sealed parts.

|

|

The support of the inner shell with the outer shell is designed to be slidable to enable the inner shell to cope with ther-

mal expansion. a

heatresisting

posed

mainly

The inner shell is made of special

of

stee/,

steel

plate,

aluminium,

com-

and

chrome.

Vane Carbon shoe

material composed and silica (S102)

of alumina

(A1203)

Forced-air cooling system. In order to preventany trouble from occurring on the '% thermal

reactor

temperatures,

due

to

extremely

high

air is supplied in between

the inner and outer shells for cooling when theconditions exceeda certain level. Although will

the temperature

consequently

drop,

of the reactor

the

temperature

of the gas passing through the reactor undergoes only a slight fall and, thus, the burning efficiency of the reactor is not

Intake chamber

Exhaust chamber

reduced.

Fig. 3.12. The thermal

reactor.

It has a ceramic insulator. The

Fig. 3.14. A section view of the air pump

air injected by the nozzles in the exhaust port makes combustion

continue in the reactor to burn the CO and HC to CO2. But the flame in the engine and in the reactor is so cool nitrogen oxides are not a problem.

FUEL TANK CHECK VALVE

/AIR CLEANER

IGNITION COIL

< CANISTER >

COASTING VALVE =

Ve

a)

=

Ve

r

THROTTLE || POSITIONER| _| Sf

K

aa

=

OIL SEPARATOR VENTILATIQN VALVE

——s

|

f

sae ra

- DISTRIBUTOR

W

1 ANTFAFTER-( |* k= | BURN VALVE ===, fl &

(f°_] AiR PUMP CHEC

Sat

fa

(¢—

tal

“AIR

L

TION SWITCH

ft

ja

CONTROL [VALVE ——E

ee)

J

tg SS |L

AIR SUPPLY VALVE — AIR PUMP

[

“BATTERY

\ WIRING COLOUR

CODE

R REO

\

G GREEN B

BLACK

Y

YELLOW

Se \\

L BLUE

\

W. WHITE

—

FRESH AIR

Seas

= oe Sees

oe JR

aie.

+ VENTILATINGA

©

teres INJECTION vera | /

NON RETURN VALVE ‘THERMAL REACTOR

CONDENSE TANK~’

Fig. 3.13. The genera! arrangements of the emissions control

system

fe FUEL TANK

Chapter 3/Fuel system and carburation: Exhaust and emission control

&

switch contacts after disconnecting their leads. Suck. The switch should go off when the depression drops to 7.1 in Hg (180 mm Hg), and come on again when the suction is released, at 4.75 in

15 Control system: Component checks

1 Air pump. Connect an air pressure gauge into the hose from the pump to the air control valve by a ‘T’ piece. Block off the outlets from the air control valve to the air cleaner and the thermal reactor cooling jacket. Run the engine at idle speed. The

pressure should be 0.47 - 0.65 Ibf/in2 (0.033 - 0.046 kg/cm2).

Hg (120 mm Hg). 9 Non-return valve. Remove to the thermal reactor. Check 10 Air injectors. These are Access to them can be gained

the hose from the air control valve that the valve moves freely. only checked at major overhauls. by removing the sump.

2 Air control valve. With the gauge connected as for the last test, unblock but leave disconnected the two pipes from the valve to the reactor

and

the air cleaner;

the engine still idling.

Now increase the engine speed to 3,000 rpm. Air should now blow out of both outlets, and the pressure should have risen to

1.3 - 2.0 Ibf/in2 (0.11 - 0.14 kg/cm2). Now disconnect the lead to the air valve’s

solenoid.

The

pressure

should

now

drop to

0.036 Ibf/in2 (0 - 0.025 kg/cm2). Air should be flowing out of the outler

to the reactor jacket, but none from that to the air

cleaner. 3 Throttle positioner. Remove the pipe from the coasting valve to the air cleaner, and plug it so that the engine will run properly in the test that follows. Start the engine and run it at 2,000 rpm.

Disconnect the lead to the coasting valve solenoid, and wire the solenoid direct to the battery. Now close the throttle suddenly. The engine should slow down and run at 900 - 1,000 rpm. Adjust the nut on the positioner as required. Then check that when the soldnoid is disconnected from the battery the idle returns to its normal 800 rpm. 4 Coasting valve. Tap a vacuum gauge with a ‘T’ piece into the depression pipe connecting the coasting and air control valves. Start and warm up the engine. Run it at about 2,500 rpm. Suddenly close the throttle. The gauge should read O - 1.2 in Hg (0 - 30 mm Hg) depression whilst the engine is slowing down, and until it gets to about 1,300 rpm, when the control unit will switch off the coasting valve’s solenoid, when the depression

should increase to more than 16 in Hg (400 mm Hg). If the valve does not work properly check the current flow in the lead to the solenoid. Listen to the solenoid working when connected direct to the battery. If not already done, check the throttle positioner. Check the pipes for leaks or blocks. 5 Anti-afterburn valve. Remove the air inlet hose, which comes from the air cleaner by way of the coasting valve. Run the engine at idling Run the Vacuum engine at

speed. If suction is felt, the valve should be changed. engine at 3,500 rpm. Close the throttle suddenly. should be felt for just 0.2 - 1.0 secs. Then run the idle. Disconnect the lead to the solenoid, which will

allow engine depression to work the valve. Air should be sucked in whilst the wire is disconnected. 6 Air supply valve. Remove the hose into the air supply valve from the air cleaner. Start the engine and let it idle. Close the inlet to the valve from which the pipe was removed. The engine speed should not fall by more than 30 rpm. If it does it indicates excessive air leaking in. Disconnect the lead to the air supply

16 Exhaust manifold/thermal reactor removal 1 The exhaust removed if the damaged.

2

manifold or thermal reactor may need to be gasket develops a leak, or if the reactor is

Remove the air cleaner. (photo)

3 Remove the alternator, air pump, and air conditioner air pump if fitted. 4 Disconnect the carburettor from all controls, and the fuel pipes at the large union nut for the circulation valve, and then remove the inlet manifold from the engine with the carburettor and emissions control valves still attached. 5 Undo the exhaust pipe flange at the manifold. Remove the wire grille on cars so fitted. Slacken the pipe mounting on the gearbox so that it can be moved about a bit. 6 Undo the nuts holding the manifold or reactor to the engine. In the case of the thermal reactor a special short handled spanner may need to be made up by cutting up a normal one.

17 Exhaust pipe 1 The pipe is made of heavy gauge steel, so should last well. 2 The centre section from the manifold back to just in front of the rear axle will often have to be removed complete to disconnect the exhaust manifold. The studs at the manifold joint are at about 45° so the joint cannot slide apart easily, when for instance pulling the manifold sideways off the engine, or removing the engine straight forward. 3 When the joint at the manifold is undone, a new gasket should be put in.

4 The joint just in front of the axle has a sealing ring. This can be reused a number of times. Scrape it and the seating in the pipe clean. Then coat is with grease before reassembly. 5 The bends in the tail part of the pipe, with the silencer, make is difficult to get it out or thread the new one into position. The car should be over a pit or on a lift, to give room, and the weight taken off the springs to give more clearance between axle and body.

18 Fault-finding

valve solenoid. The valve should then allow air to flow. 7 Control unit. a) Connect a timing light or neon plug tester to a high tension lead from a trailing plug. Remove the plug from the thermo-sensor on the engine. Run the engine. The timing light will show when the ignition for the trailing plugs is working. It should work below 1,900 rpm (+ 300) and above 4,000 rpm (+ 200). Now join the two leads in the thermo sensor plug. Now the

1 The initial steps in fault-finding were described in Chapter 1. The action to be taken depends first on making sure that it is not the ignition system to blame. Having decided that it is not, then the air and fuel supply is presumably at fault: This is the fuel system, carburettor, and emissions control system. The fault can be broadly classed in two types. Either it is a shortage of fuel, in

b) Connect an ammeter in series with the leads to the solenoids of the various valves. By testing this way no additional current

too much air, let in by the emissions control system. 2 As the carburettor is really two separate systems inside the one body, provided the fuel reached the float chambers, the

will flow through the control unit, so it will not be damaged. Current should flow at engine speeds of 800 - 4,000 rpm, but not above 4,200 rpm to both air control and anti-afterburn valves. There should be current to the coasting valve only above about 1,250 rpm. Current should flow to the air supply valve whenever the ignition is on. 8 Distributor vacuum switch. Remove the vacuum tube from the capsule of the leading distributor. Put on the capsule a length of a hose, then a ‘T’ piece. On one end of the ‘T’ piece connect a vacuum gauge. On the other put a length of clean hose which can be sucked

by mouth.

Connect

an ohmmeter

across the vacuum

which case the fuel system and carburettor is to blame, or it is

engine will run. So carburettor faults are likely to give erratic running rather than complete failure. 3

The tests to prove the fuel pump

were given on the chart in

Chapter 1. 4 The emissions

control system is most likely to give erratic running, but the air supply valve could make the engine stall in

traffic, and then prevent it restarting. If the tests on the chart in Chapter 1 indicate the fuel system is satisfactory, then the emissions control system must be eliminated next. 5 To eliminate the emissions control system all sources of sur-

66

FROM AIR CLEANER COASTING

VALVE

THROTTLE

INTAKE

|

ANTI AFTERBURN VALVE

jee:

POSITIONER

MANIFOLD

a [Ect

es

TO AIR NOZZLE TO AIR CLEANER

CHECK VALVE

FROM

CONTROL

AIR PUMP

BOX TO THERMAL REACTOR

AIR CONTROL

FRESH AIR C——> VACUUM

=?

Fig. 3.16. The deceleration contro! system

VALVE

Chapter 3/Fuel system and carburettor:

plus air to the inlet manifold must be sealed off. Note that the air control valve is delivering air pump output to the exhaust injectors and thermal reactor cooling jacket, so need not be touched. But the inlet manifold connections for the air delivery pipes from the supply valve, coasting valve, anti-afterburn valve, and crankcase ventilation valve must all be sealed off. The way this is done depends on the materials to hand; whether you are

broken down on the road, or at home. Individual pipes can be blocked by pencils or bolts. Or the pipes themselves can be refixed in ‘U’ bends just joining one manifold tapping back to the next. Close off the vacuum sensing pipe to the coasting valve as well.

6

The engine

must

not be run for long with the ventilation

valve

Exhaust and emission control

disconnected.

With

the coasting

valve

67 disconnected,

to the table that follows for causes of erratic system defects. Note particularly whether occurs on light throttle, which means it is a parts of the carburettor, or on full throttle throttle working.

running due to fuel the erratic running fault in the primary with the secondary

“

16.2a On emissions controlled cars there are additional connections to the top of the air cleaner,

16.2b and others on the left

16.4 Do not muddle the hoses from the control box or the air or vacuum pipes

To air injection nozzle To air cleaner

| Check valve

Safety valve

LLUMN “2

Ss,

Air cut valve

Relief valve

aN AVL

From air eS] pump

Diaphragm Solenoid

To thermal reactor Air chamber

Vacuum chamber

:

To coasting valve ¢==d

valve

16.5 Removing the exhaust is difficult a= ow

EES Hall: Vacuum

Fig. 3.15. The air control valve

From combustion

Insulator

——

|

chamber

{

A \| oe |

Fig. 3.17. A plan section of the thermal reactor

«— =

Exhaust gas Cooling air

its

control connection to the air control valve will make the latter Pass air at all times to the thermal reactor cooling jacket, which is a safe condition, but will result in exhaust emissions being incorrect. 7 If the fault is found to be in the emissions control system, then each item must be checked one by one. 8 If the fault is not in the emissions control system, then refer

68

Fuel system faults giving erratic running

a

Idling

Effect of Choke

Probable defect

at speed. Poor pick-up on part throttle.

Will not idle.

Does not help.

burettor (Primary chokes).

2. Starts well hot or cold. Coughs and splutters when large throttle opening tried: Can hardly move.

Will help a bit to get car Idles well.

going.

Blocked main jet in primary or secondary system.

Normal.

Little effect.

Starting and running 1. Starts well cold on choke. Only starts hot on wide throttle. Runs well

3.

Blocked idle jet and for passages in car-

Very difficult to start cold: Has to

be ‘Warmed up on the Starter’. Once warm goes perfectly.

Air

leak:

Brake

servo

connection.

Emission control system.

4. Engine tends to stall. Difficult to start hot. Goes well. High fuel con-

Carburettor flooding:- Float jammed.

sumption. Smell of petrol, and possibly petrol in drip tray under carburettor.

Will not idle.

Makes matters worse.

Needle valve stuck or damaged or dirt on seating. Float set wrong: level too high on float chamber.

Sometimes does, others not.

Sometimes helps.

Water in fuel.

5. Varying symptoms. Sometimes cures itself. Sometimes goes in jerks, othertimes engine cuts out.

6.

Difficult to restart hot. In ex-

tremely hot weather may cut out

Fuel vapour lock due to hot weather and combining circulation system op-

when moving. Worse in mountains Engine restarts when allowed to cool.

Once restarted idles well.

Makes little difference.

perative with engine overheating. Suspect fan coupling; ignition timing wrong; Obstruction to air flow.

7.

Once restarted, behaves well.

Makes matters worse

Engine won't restart.

Plugs wet with petrol. Slowly press accelerator to floor; hold it there and work starter. (Not really a fault, just a

temporary crisis).

8.

Engine starts well hot or cold,

then runs well initially but peters out. Driving slowly may allow it to recover if symptoms mild.

9.

Engine is initially running on the float chamber. There is a partial blockage between needle valve and tank. Per-

Initially idles well. Will not idle after petering out unless symptoms

mild.

Will not rescue engine.

haps filter, or a weak pump.

Helps a bit.

Dirt getting sucked into main jet, but falling back out of it when flow stops. eg. flake of dirt; wisp of rag. If latter, take out jet and burn it out.

Probably will not help.

Carburettor icing. Check thermostat. Buy top quality but NOT high octane fuel.

Engine starts well hot or cold,

then runs well initially but peters out. Driving slowly may allow it to recover if symptoms mild. 10. Ditto but damp cold weather. Cures itself if given a couple of minutes rest.

Idles well.

Probably won't idle.

Chapter 4 Ignition system Contents Specifications

Timing adjustment . bate a Automatic ignition advance check. Distributor overhaul eae ee Ignition coils and ballast apeais The condenser we Dual ignition function: eeack, Fault finding.. oes = =e: AahwWnN-

General description Choice of spark plugs Plug cleaning and gap setting The distributors ... Contact breaker Cleaning ead ubricenien Contact breaker gap setting

ses

= aa

Specifications Type

ace

Dual coil and distributors: Trailing and leading Two each chamber: Trailing and leading.

Spark plugs Plug type: Normal

Champion Denso NGK Champion Denso NGK Denso NGK

_...

ats

on

a

io

Automatic advance: Normal engines Centrifugal: Trailing Leading Vacuum: Trailing

Leading Automatic advance:

B 7EJ N80B W 20 E G2 B 6EJ W 25E G2

B 8EJ Q.030 - 0.035 in (0.8 - 0.9 mm) 01016 - 0.020 in (0.40 - 0.50 mm) Trailing 5° ATDC

Plug gap ... =. = Distributor contact breaker ca Ignition timing static

Timing marks

N78B W 22 E G2

Leading TDC Crankshaft pulley

Starts Starts Starts Starts

500 500 100 100

rpm. rpm. mm mm

Max 5° Max 6° Hg. Max Hg. Max

at 1500 distributor rpm at 1700 distributor rpm 17%° at 400 mm Hg 11° at 400 mm Hg

Starts Starts Starts Starts

500 500 180 100

rpm. rpm. mm mm

Max 17%° at 2500 distributor rpm Max 10° at 1500 distributor rpm Hg. Max 13° at 420 mm Hg Hg. Max 11° at 400 mm Hg

Engines with thermal reaction

Centrifugal: Trailing Leading Vacuum: Trailing Leading Automatic advance tolerances

...

Centrifugal

+ 1°. Vacuum + 1.59

Automatic advance caracteristics Condenser capaicty Contact breaker dwell Firing order

are Linear

Starting ignition ...

Ballast resistance on leading coil Trailing ignition cut:-

Thermal

reactor Sambustion

0.27 micro Farad 550 - 619 ila,

From 1900 (+ 300) to 4000 (+ 200) engine rpm If manifold depression 180 mm If engine warm

Hg (7 in Hg)

70

Chapter 4/Ignition system

1

General description

1

The

RX2’s Wankel

is a petrol burning internal

combustion

engine, using spark plugs, coil and distributor, just like a piston engine. So all the components are basically the same. However the ignition requirements of the Wankel are different, so the

detailed arrangements are very different. 2 The major difference is the need for two spark plugs. At the end of the compression phase the engine’s rotor has squeezed the

air/fuel mixture into the thin but long small space at the neck of the epitrochoid. The phrase ‘Top Dead Centre’ coined for the

weather, the engine may show signs of plug fouling indicating ‘hot’ plugs are needed. The signs are rough running, poor driveability, and in extreme cases, difficult starting, which can be temporarily cured by driving the car hard for about two miles. 3 The need for ‘cold’ plugs is shown by rapid plug wear. Plug wear in its turn is shown up by ragged running and difficult cold starting due to the gaps burned wide. 4 However, most people most of the time will be best off using the standard plugs. 5 Do not use plugs other than those recommended. Cheaper plugs will last a shorter time, and if they fail, they could ruin the engine.

.

piston engine is used to describe that instant when the combustion space is at its minimum size. It is then divided into two equal sized portions. In such a shaped combustion space the propagation of the flame after ignition will be slow. So a spark

plug is put in both parts. The leading plug is that one to which the rotor apex gets to last. The leading plug has the greatest effect, as the combustion spreading from its spark can burn ina space ever growing in size as the rotor sweeps on. 3 When the engine is dismantled it will be noticed that there is only avery small hole to the chamber from the threaded hole for the trailing plug, whereas for the leading plug there is a hole the same diameter as the spark plug. When the apex seal on the rotor passes over the trailing plug hole compression pressure in the next space on the rotor, which at the time the one in front is on

combustion, is not very high. So there is a great pressure difference between the two rotor spaces on each side of the apex seal. If there was a big plug hole there would be a great flow of gas from one side to the other as the seal passed over. By the time the seal gets to the leading plug, combustion pressure has gone down in one space, whilst compression pressure has risen in the next, so pressure is nearly equal on the two sides of the apex. So a large plug hole is acceptable. (photo)

1.3 The trailing plug has a small hole

4 Ina piston engine each piston has its own plug, and that plug is cooled by a great waft of incoming mixture with fuel still evaporating, on each induction stroke. On the Wankel the plug serves each rotor space in turn, and is always at combustion temperature, as the induction and compression phases are done in another part of the chamber. So the spark plugs have a far more arduous duty than in a piston engine. As a result expensive

types must be used, and even they do not last as long as in a piston engine. 5 Because of the dual ignition a complete breakdown on the road due to ignition failure is unlikely. The engine will run on the leading ignition alone with scarcely any noticeable temperament or loss of performance. It will even go on the trailing ignition alone, though then there is very noticeable weak performance:

On

cars

with

thermal

reactors,

whose

control

system will cut the trailing ignition under various circumstances, there will be further signs of temperament if the leading ignition has failed. 6 The thermal reactor is used to complete combustion so that the exhaust emissions do not contain unwanted products. Under some conditions of running there are not enough of the partly burned gasses coming out of the exhaust to sustain combustion in the reactor. So the control system is set to cut the trailing ignition in those circumstances, thus making combustion in the engine

less efficient,

so

more

is left to

burn

in the

thermal

reactor.

2

Choice of spark plugs

1 In the specifications it will be seen that ‘hot’ and ‘cold’ plugs are listed as well as the normal ones. A ‘cold’ plug is one that runs cold because it is constructed with a better caoling path to lead heat away from it. The points of a ‘cold’ plug will be burned away more slowly than one running hotter. However when driving gently, as in traffic the ‘cold’ plug may run so cool partly burned products, especially oil from the metering pump, coliect on it, so it will foul up. 2 \nacar used mostly in town traffic, and particularly in cold

Fig. 4.1. Two plugs are needed because of the long thin shape of the combustion chamber at the moment of ignition. This moment is still called “Top Dead Centre’ to conform to piston engine practice.

71 SPARK

TRAILING astitht

fe (

aaa

PLUGS

\ LEADING ‘DISTRIBUTOR

N is y

‘

My DY an

Ne \

b,

%

O N

an CONDENSOR

—

li 0

$

oo N

©)

BALLAST

Pode!

RESISTANCE— TRAILING

LEADING

COIL

COIL

(12 VOLTS)

(8 VOLTS)

RMAL_ oe

RELAY

THERMAL REACTOR CONTROL UNIT

va

CIRCUIT CIRCUIT

RELAY

IGNITION |SWITCH

BATTERY

Fig. 4.2. The dual ignition circuit

IGNITION STARTER CONTROL

|[1

fFCONDENSOR

Chapter 4/Ignition system

72

3 1

Spark plug cleaning and gap setting The spark plugs should be cleaned and their gaps reset every

4,000 miles (6,000 km),

ready for the next 4 The circlips distributor plate out. Whilst they

(but not

maintenance time. and screws holding the contacts to the should be removed, and the two parts taken are out the distributor should be wiped clean

immersed

in cleaning

liquid). Some

oil should be

2 The plugs can be cleared and regapped once, and the next time it is due they will have to be replaced. It is suggested that two sets of plugs are used, so the new second set can be fitted, and then the old ones cleaned and reset at leisure. 3 The plugs should be cleaned by sand blasting. Then the remnants of sand should be knocked out of the plugs with a clean air blast, whilst the plugs are gently tapped with a hammer on the side of the body. Finally the threads should be wiped clean.

squirted through to the centrifugal advance mechanism underneath. 5 Reassemble the cleaned, or new, points, with a trace of oil on

4

1 Having cleaned the points as described in the previous section, and ide: !ly with the distributor off the engine, turn it over until the cam opens the points to their widest.

The gaps should be set to a clearance of 0.030 inch (0.8 mm).

It is difficult to get a normal feeler into the gap, so ideally a wire

feeler should

be used. The gaps are set by bending the side

electrodes. Under no circumstances must any pressure be put on

the central electrode, lest the porcelain insulator nose be cracked, and later drop a chip into the engine. 5 lf there is a crisis on the road, it will usually be found the trailing plugs are in better condition than the leading ones, so they can be changed over. 6 The spark plugs are fitted into the aluminium rotor casings. The threads are not very strong, so the plugs should not be tightened hard.

4

Minor parts vary, because both the centrifugal and vacuum ignition advance have different characteristics. On cars with

thermal reactors, the leading distributor’s vacuum advance capsule also has a switch to control the cutting of the trailing ignition. 2 Both distributors, their mountings in the engine, and the spark plug holes in the rotor casings are all marked with ‘T’ or ‘L’, so if leads are removed, they can readily be sorted out.

(photo) 3 The high tension plug leads are made of cloth impregnated with carbon, to give a high resistance for the suppression of radio interference. They should be treated with care. After some time they can fail due to age, and need replacing. 4 Under the plate that supports the contact breaker is the mechanism worked by centrifugal force that gives the automatic ignition advance. 5 The distributors can be readily removed from the engine.

Now set the gap.

6

Contact breaker gap setting

2 Slacken the clamping screws holding the stationary contact, so they will allow the contact to move stiffly. (photo) 3 Insert a feeler gauge of 0.020 inch (0.50 mm) in the gap. 4 With a screwdriver prising at the side of the stationary contact move it so that the gap is correct, just gently touching the feeler. Try a feeler set at 0.021 and 0.19 inch to check.

5 Carefully tighten the contact clamping screws, so that the setting is not disturbed. Then recheck the gap. 6 Then refit the distributor if it was removed from the engine.

7

Set the timing.

7

Timing adjustment

1

The timing adjustment is set by moving the distributor within

As the timing

is likely to need resetting anyway,

it may

be

3 Once the engine has run a few thousand miles the contact breaker burns, getting a lump on one contact, and a hole on the other. It is impossible to check the gap in this condition. The lump must be rubbed off one contact. The one with the hole need not be completely cleaned up, provided there is a good

on

which

the other can work. The

that encloses its drive shaft. (photo) 2

If the complete drive shaft has been removed, and the timing

lost, refer to Chapter 1/31 (engine reassembly). 3 Having set the contact breaker gap, turn the engine over until the timing pointer on the front cover points to the leading notch

in the pulley (white). This is TDC. (photo) 4 Slacken the nut on the stud in the adjustment slot of the leading distributor. Move the distributor gently till the contact breaker points just open.

5 The best way to see just when the points open is to rig a test light from a convenient 12 volt source (the battery, or if turned

on, the

ignition

itself)

to the terminal

on

the

side of the

distributor, having taken off its normal wire. The light will go out when the points open. Such a light is an important part of fault finding equipment, so is well worth making out of a parking lamp bulb, and length of wire.

way. the contact

found most convenient to remove the distributor from the engine to work on the bench. Having unclipped and lifted off the distributor cap, the only additional job is to unplug the low tension wires from the side of the distributor, pull off the suction pipe at the vacuum advance capsule, and then undo the nut On the stud in the adjustment slot that holds the distributor down onto its drive shaft.

surface

the limits of a slot on the pedestal of the distributor mounting

6 Tighten the nut, and turn the engine onto the next timing mark, and set the timing for the trailing distributor in the same

Contact breaker cleaning and lubrication

1 It is a 4,000 mile (6,000 km) task to clean breaker points, and lubricate the distributor. 2

6

The distributors

1 The trailing and leading distributors are mirror images of each other, one rotating clockwise, and the other anti-clockwise.

5

the moving contact pivot, and a smear of grease on the cam.

rubbing should

be

done with an oil stone, as used for sharpening carpenter's tools. The points can be cleaned once, and then should be replaced. Again, it is recommended a spare set is kept, and this fitted when the distributor is in bits, and the other points cleaned at leisure

7 The engine can be turned over by the crankshaft pulley. It must always be turned over forwards when doing the timing, otherwise the backlash in the distributor drive gears will give errors. Whilst the distributor is being adjusted its spindle should be held ‘back’ against the direction of rotation, to hold its drive against the engine. The correct direction can be felt by the springs in the centrifugal advance mechansm. The drive is solid when held back, but springy if being pushed forward.

8

Automatic ignition advance check

1 If the automatic ignition advance is suspect, the best way to check it is to use a garage’s electronic diagnosis equipment. 2 Toa limited extent the advance can be checked without it. 3 The centrifugal advance can be assessed by twisting the rotor arm gently forwards. It will move, moving the automatic advance mechanism against the springs that pull the centrifugal bob-weights inwards. The movement should be smooth, and the rotor arm should be pulled gently back by the springs.

73

Chapter 4/Ignition system

4.2 All distributor parts are marked with ‘T’ and ‘L’ for the trailing and leading

6.2 To set the points turn the engine till the points are as wide as they go, then

systems

slacken the clamping screw

% ke

Be,

6.4 Put a feeler gauge for 0.020 inches in the gap, and prise the points into posi-

so

ae

He

Bo

%

tion with a screwdriver

ee .

7.1 The timing is adjusted by moving the distributor within the confines of the slot for the clamping nut

Lote

Soames

i

s

7.2a If the timing has been completely lost by removing the drive shaft, refer to Chapter 1/31

4

ms

je

mS

ne

=

oS

7.2b The timing will not be completely lost as the drive has slots; these are assy metrical

Tocheck the vacuum advance drill a small hole (3/16 inch) in

the distributor cap near the fixing for the clip. Start up, and open and close the throttle. The contact breaker should be seen to move to and fro as the depression changes as the throttle is opened and closed. Then plug the hole with sealing compound. 5 The combined effects of the two automatic systems can be seen by shining a stroboscopic timing light on the timing marks. If then the engine is run with the vacuum pipe disconnected, the action of the centrifugal system alone will show. Such a light, if available, makes a good check. It should be connected in accordance with the maker’s instructions to each ignition system, separately, and in turn.

9 7.2c It would not matter if the timing was 180° out as the rotor arm is double ended

aoe oe 7.3 The timing pointer is on the front cover just above the crankshaft pulley, on which are notches

Distributor overhaul

1 The distributor will only need further overhaul after high mileages in the order of 150,000. Then the factor that might call for it is wear of the spindle, so that the cam wobbles about, spoiling the contact breaker gap setting, and so the timing. 2 Before starting work check what parts your dealer is likely to be able to get. It may prove better to get a complete distributor. 3 Ona car with a thermal reactor, or perhaps on any car used somewhat gently, it probably is not worth fussing about the trailing distributor, as any variations in this are unlikely to be significant. 4 Remove the distributor from the engine by undoing the nut on the stud in the adjustment slot. 5 Unclip the vacuum arm from the contact breaker plate. Undo the screws holding the capsule to the distributor body, and take it off. 6 Remove the contact breaker from the base plate. 7 Remove the terminal stud and insulator. Remove the

condenser. 8 Remove the screws holding the contact breaker base plate to the distributor body. Take out the base plate, and the clips for the cap.

Chapter 4/Ignition system

74

9 Take out the screw at the top of the distributor spindle. Take off the cam, disengaging it from the centrifugal advance mechanism. 10 From the bottom of the shaft, take off the locking washer and other washers. Pull the spindle/shaft assembly up out of the

to fit it after a puncture, so there is a possibility of having one ignition failure, and driving on in ignorance, till the car finally fails after a second.

distributor body.

then the fault is much more noticeable. 3 It is recommended that after the 4,000 mile plug change and

1 The coil has a primary, or low tension winding, fed from the ignition switch, and connected to the contact breaker points. A voltage of high tension is induced in the secondary windings when the contact breaker points open.

When

the starter is cranking the engine it takes most of the

battery voltage, and that available to the coil drops from the nominal 12, which is 14 or 15 volts when the engine is running to only about 10 volts. Running on such a low voltage low tension, the high tension voltage drops in proportion, at the very time when a strong spark is needed to start the engine. To overcome this problem the leading ignition has a device to boost it at the moment of starting. The leading coil is designed to run ona low voltage, such as will be available when starting. So at that moment it will be efficient. Indeed, it is run slightly overloaded, to ensure

the best performance.

Once the engine starts, a relay

reconnects the leading coil primary wiring so that it is fed through a resistance, which reduces the voltage to a safe level.

(photo) 3

The relay for making the changeover is worked by the starter

circuit of the ignition switch. The relay is just behind the right headlamp, in the engine compartment, near the battery. 4 It is not worth giving a boost by a ballast system to the trailing coil, as it is not much help when starting up.

1 The condenser is put across the contact breaker points to help them cut the current in the low tension circuit quickly. The current flowing at the instant of Opening the points carries on into the condenser, rather than jump across the gap.

This clean break in the LT current builds up a higher voltage

in the HT. It also reduces arcing at the points, so makes them last better.

3 Should the condenser fail, the ignition will be less efficient due to the reduced HT voltage. This will probably stop the engine running. Anyway it will make it very difficult to start. It will make an increased spark visible at the contact breaker points, though practice is needed to notice it. 4 Radio test equipment is needed to test a condenser. If one is suspect, the best test it to try a new one.

12 Dual ignition function check 1

hardly

noticeable

difference,

on the

the ignition is suspect,

4 On cars with thermal reactors, take the ignition vacuum pipe off the leading distributor, so that the reactor control system

cannot cut out the trailing ignition. 5 Start up, and run the engine at about 2,000 rpm. 6 Remove the low tension wire from the trailing distributor. The engine is now running on the leading distributor only. It is unlikely that there will be any noticeable drop in engine speed. 7 Reconnect the trailing LT. 8 Disconnect the low tension of the leading distributor. Q The engine speed will drop quite a bit. The amount it drops cannot be measured in rpm, as the tachometer counts the leading ignition, so will drop to zero when the leading ignition is cut. On the trailing ignition the car should run, but it cannot be expected to idle, and it will only start with difficulty. 10 Reconnect the leading ignition, and note the engine speed up as it comes into action. 11 Refit the vacuum pipe to the leading distributor. 12 If an ignition neon test lamp or timing lamp is available, it can be put to each ignition circuit in turn. When using sucha tester, the functioning of the thermal reactor cut-out of the trailing ignition can also be seen. This will be cut when the engine is between 1900 and 4000 rpm, and the manifold vacuum more than 180 mm Hg; which it will easily be if the engine is running, with the car halted. The engine must also be warm. The temperature control can be checked by running the engine with the plug to the sensor disconnected, in which case the ignition should not be cut. With the leads from the sensor short circuited, the ignition should cut. ;

11 The condenser

2

The car will run, with

leading ignition alone. It also goes on the trailing system, though

distributor check, or at any time when the system is checked as follows.

10 Ignition coils and ballast resistance

2

2

Since there is dual ignition it is very unlikely that the ignition

will cause the car to break down on the road. But just as there are people who find their spare wheel has no air when they come

13 Fault-finding 1

The

major factors in fault-finding were discussed in Chapter

1/31 onwards. 2 The wires for rewiring described in Chapter 1/40 should be carried, and their use tried out at home. 3 If a coil or condenser is suspect, the best test is to try another.

The

coils can

be switched

in

a moment

by merely

plugging cver the king leads from the coil to the centre of the distributor

cap.

But note

that when

this is done the boost for

starting from the ballast resistance will be wasted at the trailing plugs. 4 If suspicious of the condenser, compare the little spark at both contact breaker points by flicking them with a small screwdriver. The condensers can be changed over between the distributors. 5 The actions mentioned in paragraphs 3 and 4 above should not be done haphazardly, but only after following the sequence in Chapter 1, and it becoming apparent that they are fault.

Fig. 4.4 appears on page 76

FIG. 4.3. THE

DISTRIBUTOR top)

Hair pin spring Contact breaker plate QAwWMO™

~OON O Centrifugal weight

11 Diaphragm 12 Shaft

16 Clip 17 Condenser

13 Washers 14 Washers 15 Oil seal

18 Washer 19 Lock washer

10.2 The two coils are not similar

e) Key Switch

aN

Ignition

Coll

ee

Battery

Fig. 4.4. The changeover switching for the coil ballast resistance, that puts full battery voltage to the leading coil when the starter is being used.

Chapter 5 Clutch Contents

Specifications General description Removing the clutch Clutch overhaul ...

Clutch adjustment... Bleeding the Overhaul of Overhaul of Clutch fault

= Withdrawal lever and bearing Refitting the clutch

ee

ae

as

see

hydraulic Shin the operating cylinder the master cylinder diagnosis se tas

ass eas

xd ee as s¥5

sh. es ee =

’ iss

6 7 8 9 10

aOhwWN—

Specifications

Spring ee Pressure plate diameter: 4nner ia Outer Friction plate diameter: Inner ... Outer Friction plate thickness Clearance push rod to mitre Pedal free travel. Master cylinder bore Operating cylinder bore

Single dry plate Diaphragm as ses

not a

5 on

150 215 154 215

ie

General description

1 The clutch is a diaphragm spring type. It is actuated hydraulically. 2 As the clutch is sandwiched between the engine and the gearbox; access to it is difficult. Repairs to it are the type where the labour completely outweighs the cost of spares. The clutch should therefore always be treated very carefully. If either the engine or gearbox are out of the car the opportunity should be taken to overhaul the clutch, and new parts fitted generously.

2

Removing the clutch

1

If neither the engine or the gearbox needs to come out for

other work, then the decision must be taken as to which of these will be removed to give access to the clutch. 2 The professional way, and the quickest, is to remove the gearbox. This is described in Chapter 6/2. However, much work must be done under the car, in particular the actual removal of the clutch.

3 To remove the engine involves much more work. But much less is under the car, and it does not involve lifting the car to the height

(or using a pit) needed

(5.9 (8.5 (6.1 (8.5

in) in) in) in)

8.5 + 0.3 mm (0.335 + 0.012 lever

Master cylinder maximum pete eigarance piston to cylinder ee saa Maximum out of true: friction Riete aa Maximum play: plate to shaft ... Tightening torques: cover to flywheel

1

mm mm mm mm

to take the gearbox

out under-

neath. This is described in Chapter 1/8. 4 Having removed the engine, the clutch can be unbolted from the flywheel. Undo all the bolts round the rim of the cover gradually and diagonally. As they slacken they are unloading the clutch spring, and if it is done carelessly there is a likelihood of the clutch flying apart dangerously.

in)

3.0 mm (0.12 in) 20 - 30 mm (0.8 - 1.2 in) 15.9 mm (0.625 in) 17.5 mm (0.687 in) 0.15 mm (0.006 in) 1.0 mm (0.039 in) 0.3 mm (0.012 in) 2.0 Kg m (15 lb ft)

5 Note that two of the bolts are not threaded to the head, and have parallel shanks. These are fitted into reamed holes to locate the cover accurately on the flywheel. One of these holes is near a small marking hole in the rim of the cover, and the other diametrically opposite. 6 Lift off the clutch cover, with spring and pressure plate. The friction plate will also now be free.

3

Clutch overhaul

1 Clean the rear face of the flywheel, and the complete clutch assembly, whilst doing so checking the nature of the dirt. It should be dry dust. If there is oil about trace where it has come from. If it has come from the centre of the flywheel this is going to have to be removed to replace the rubber rings around the plug in the end. Oil coming out round the front of the flywheel indicates a new rear main bearing oil seal is needed. Do not get cleaning fluid in the spigot bearing in the centre of the crankshaft where the clutch shaft rests. 2 Examine the surface of the flywheel. If the clutch bearing surface is rough it will have to be removed for grinding, or if very serious, replacement. However this is not likely. 3 Examine the clutch pressure plate. If this is scored or in any way rough it will have to be replaced. 4 Examine the clutch spring. If there are any visible signs of failure it will definitely have to be replaced. It will also have to be replaced if previous performance indicates it was weak. If the clutch had been slipping, yet on dismantling it was found that there was free play in the withdrawal mechanism, that the friction plate linings were not worn to the rivets, nor spoiled by oil,

78

Chapter 5/Clutch

ee UU UE EEEEEESSEEEEEEEEEEEEEEEE====t ono oe

then

the slippage

must

be assumed

to have

been

caused

as it does

not

last all that long, and otherwise

it may

soon call for the labour of stripping again. If there is oil, or black carbon deposits of oil burned off, any leak must be traced. If the plate is to be used again there must be a good depth of friction material above the rivets, and the spring drive cushion in the hub must be in good condition. If in doubt, compare it with a new

one. 7 If the gearbox has been dismantled, put the input shaft into its spigot bearing in the crankshaft, and check it moves

smoothly, with little free movement.

Put a little molybdenum

disulphide grease in the spigot bearing.

8 If there is an oil leak by the flywheel, or the flywheel come off to replace the spigot bearing; refer to Chapter 1. gearbox input shaft oil seal needs replacing refer to Chapter 9 Check that the friction plate (even the new one, if replaced) slides freely, but not loosely, on the shaft splines.

4

must If the 6. being

Withdrawal lever and bearing

1 Remove the withdrawal lever and bearing from the clutch housing on the front of the gearbox. The bearing is clipped to the fork on the end of the lever, and the lever clipped on a pivot

on the housing. (photo) 2

-__—_

by a

weak spring. 5 If there is any fault in the clutch cover, spring and pressure plate assembly, the whole thing must be replaced. 6 Examine the friction plate. It is probably best to replace it anyway,

ee

Do not immerse the bearing in cleaning liquid, as it is sealed.

The liquid will get in, but cannot be dried out, or new grease put

6

Clutch adjustment

1 Clearance is required at two separate points. There must be clearance between the withdrawal bearing and the fingers of the diaphragn spring. Otherwise the bearing will get excessive wear, and the load being taken off the spring, the clutch will slip. Clearance is also needed between the pedal pushrod and the piston in the master cylinder so that the piston can return fully to the end of the cylinder, so uncovering the hole into the reservoir. 2 The withdrawal lever pull off spring will have pulled the lever so as to push the hydraulic operating cylinder piston up to the end of its cylinder. To check the clearance, pull the lever against the spring, until the other end of the lever inside the clutch

pushes the withdrawal bearing against the clutch. 3 To adjust the clearance, take off the pull-off spring. Push back the hydraulic cylinder’s rubber boot to uncover the locknut on the threaded push rod. Undo the locknut, and screw the long

adjuster nut on the end of the rod to alter its length to give the required clearance, which is a minimum of 1/8 inch (3.0 mm). 4 It should be possible to feel at the clutch pedal some completely free movement before the pedal’s push rod contacts the master cylinder piston. This clearance and that already obtained at the clutch withdrawal lever should give a total of 1 inch (25 mm) lost motion at the pedal. The clearance at the pedal is adjusted by undoing the locknut and screwing the push rod. 5 The clutch pedal has a return stop which is also adjustable. Altering it will affect the pedal free play. The clutch spring has an over-centre action, so that once the pedal is pushed part way down the spring changes from a pull-off action to a helper. The return stop, in conjunction with the push rod to the master cylinder, is adjusted to give the spring a smooth and confortable, progressive action.

in. 3 Check the bearing rotates freely, smoothly, yet does not feel dry. If in any doubt replace it. 4 Reassemble, greasing the pivot for the lever, and very lightly the lever forks, and the extension from the housing on which the bearing slides. Check the lever can move the bearing smoothly to and fro.

5

1 Find on the flywheel which of the bolt holes for the cover have threads to the top, and which two the unthreaded part for

the locating bolts. Get ready the two bolts with the parallel shanks. 2 Hold the friction plate in place on the flywheel, the longer

length of the splined boss outwards. (photo) 3 Put the clutch cover in place, and secure it temporarily with the two special bolts in their marked holes, tightening them

Fit all the

other bolts, and tighten

them

by the

fingers. (photo) 4 Now centralise the friction plate. It must be accurately in the centre if the gearbox input shaft is to pass through the clutch plate, and go into the spigot bearing in the crankshaft. The official dealer will have a special tool. If you have the gearbox dismantled, then use the input shaft itself. Without either, then a fat bar, or broom

handle,

and

accurate

checking

by eye

from

different angles must suffice. (photo) 5 Recheck the friction plate is the right way round, longer boss, and cushion drive retaining plate, outwards, (away from

the flywheel). 6

Tighten all the cover bolts gradually and diagonally, to 15 Ibf

ft (2.0 kgm). 7

When refitting the gearbox to the engine make sure no weight

hangs

on

the shaft

Bleeding the clutch hydraulic system

1

If air gets into the system the action will become spongy and

indefinite, though it is not as critical as the brakes. 2 Air will get into the system when it is dismantled, or if the level of the fluid in the master cylinder reservoir gets too low. The latter is only likely if there is a leak. If air gets in in normal use, then this indicates a fault in the master or operating

Refitting the clutch

finger tight.

7

through

the clutch, or the plate and maybe

the shaft too, will be damaged.

cylinders,

3 To bleed the clutch supply of brake fluid, a clean jar, and a short length of plastic tubing, and an assistant, will be needed. 4 Fill the fluid reservoir full; a bit above the normal mark. Put

about an inch (2 cm) of fluid in the jar. 5 Under the car clean the area around the bleed nipple on the operating cylinder, then remove its cap, and fit the bleed pipe. Put the other end of the pipe in the jar. 6 Slacken the nipple about % of a turn. Then get the assistant to push the clutch pedal down to the floor and hold it there. Tighten the nipple. Then tell the assistant to release the pedal.

Again slacken the nipple, and again push and hold the pedal! on . the floor, tightening the nipple before the pedal is released. 7 Normal pumping of the pedal as is done for bleeding the brakes is not so effective with the clutch, because the clutch has no non-return valve at the outlet from the master cylinder. 8 Repeat bleeding till air stops coming out of the bleed pipe. Do not go on so long that fluid falls so low in the reservoir that more air is sucked into the system! 9 Finally tighten the nipple, and check the action of the clutch, by the feel of the pedal, and watching the movement of the release lever under the car. Dry the nipple, and fit its cap. Refill the reservoir to the marked level. 10 Do not reuse old fluid. It attracts damp, and when damp will corrode clutch components.

FIG. 5.1. CLUTCH PEDAL ADJUSTMENT Master cylinder Push rod Lock nut Return and helper spring Return stop Lock nut Clutch pedal NQOAWD™

1.1 The clutch is simple. But either the engine or the gearbox must be taken Out to get at it

4.1 The withdrawal bearing clips on the fork end of the lever. Do not immerse

4.4 The lever clips on to its mounting in the clutch housing on the front of the gearbox. Grease the pivot

5.2 The clutch plate goes in with the

the bearing in cleaning liquid

longer end of its boss, and the plate

holding the springs of the cushion drive, outwards

5.3a The holes for the long shanked bolts are marked by a small hole

5.4 Before the bolts clutch plate must the shaft will not ing up tool is the

are tightened the be centralised or go in. The best linshaft

5.3b The other bolts and their holes are threaded all the way up. All these bolts have to be undone and done up gradually, as they take the clutch spring load

7.4 Use brake fluid in the clutch

©

8.4 Unless it needs overhaul the operating cylinder can be left attached by its flexible pipe when the boits are undone. To remove it undo the metal! pipe, and the clamping nut at the top end. Do not let the hose be twisted or pulled

9.5 Before undoing the union drain off the fluid at the operating cylinder so there is less chance of it dripping on the paint, which it will ruin

Chapter 5/Clutch

8

Overhaul of the clutch operating cylinder

1

The

operating

cylinder

should

81

reassemble the cylinder, refit it, and bleed the system. 10 Check the clutch free play.

be overhauled

whenever

it

seeps fluid, or if air is getting into the system. If a fault develops in the master cylinder, the operating cylinder should be overhauled at the same time, as once the fluid has been drained, the operating cylinder has very little more work, and if age, or bad fluid, has affected the rubber cups in the master cylinder, those

in the operating one will be in much the same state. 2 Take ajar under the car. 3 Wipe the area around the operating cylinder clean. Disconnect the flexible pipe, and allow all the fluid to drain into the jar. Throw the old fluid away. 4 Take off the clutch pull-off spring from the withdrawal lever.

9

Overhaul of the clutch master cylinder

1 The master cylinder should be overhauled if it seeps fluid, or if air is getting into the system, or if the wrong type of fluid has been used in it. 2 Drain off the hydraulic fluid at the operating cylinder. This will be needing overhaul too anyway: See the previous Section. 3 Remove the air cleaner. 4 Clean the area around the master cylinder. Put newspaper about to catch any fluid drips, as they will ruin the car’s paint. 5 Undo the pipe union from the end of the cylinder. (photo)

(photo)

6

5 Undo the two bolts holding the operating cylinder to the clutch housing, and take it off. 6 Thoroughly clean the outside of the cylinder, using alcohol or brake fluid. 7 Take off the rubber dirt excluding boot, and the push rod.

and lift the cylinder off the studs. 7 Dismantle the cylinder on a clean working surface. First clean it thoroughly on the outside with brake fluid or alcohol. 8 Take off the, rubber boot. Prise out the circlip. Then remove the washer, the piston with the secondary cup on it, then its spacer and the primary cup, and the spring. 9 Clean all the parts with brake fluid. Examine the master cylinder bore and the piston for scores or pitting. If there are any they will need replacement. 10 Reassemble using new cups throughout. Check the clearance of the pedal push rod. 11 Refill with new fluid. Bleed the system.

8 Take out the piston. If it cannot be got temporarily reconnect it to the flexible pipe on the an assistant to pump the pedal to blow it out. 9 Clean all the parts in brake fluid. Examine the cylinder and the piston for scores or pitting, and replace them. Fit new rubber cups to the piston. rubber boot. Lubricate all parts with brake

FIG. 5.2. CLUTCH 7 2 3

Boot Clip Stop washer

MASTER

out easily, car, and get

bore of the if necessary Use a new fluid, then

Take off the two nuts holding the cylinder to the bulkhead,

CYLINDER 4

5

Piston with secondary cup Spacer

Primary cup

Piston spring Cylinder

Reservoir

70 77 12 73

Washer Securing plug Baffle Cap

10 Clutch fault diagnosis Symptom

Reason/s

Remedy

Judder when taking up drive

Loose engine/gearbox mountings or over flexible mountings Badly worn friction surfaces or friction plate contaminated with oil deposit

Check and tighten all mounting bolts and replace any ‘soft’ or broken mountings. Remove and replace clutch parts as required. Rectify any oil leakage points which may have caused contamination.

Worn splines in the friction plate hub or on the gearbox input shaft, or damaged plate Badly worn roller bearings in flywheel ‘ centre for input shaft spigot Worn or loose impeller shaft

Clutch drag (or failure to disengage) that gears cannot

so

be meshed

Clutch clearance too great Clutch friction “isc sticking because of rust

On splines (usually apparent after standing idle for some length of time)

Damaged or misaligned pressure plate assembly Clutch slip - (increase in engine speed does not result in increase in car speed -

especially on hills)

Clutch clearance too small resulting in partially disengaged clutch at all times Clutch friction surfaces worn out (beyond

further adjustment). Clutch surfaces oil soaked

Renew

friction

plate and/or

Renew roller bearings Examine and rectify.

input shaft.

in flywheel.

Adjust clearance. As temporary remedy engage top gear, apply handbrake, depress clutch and start engine. (If very badly stuck engine will not turn). When running rev up engine and slip clutch until disengagement is normally possible. Renew friction plate at earliest opportunity.

Replace pressure plate assembly.

Adjust clearance.

Replace friction plate and remedy source of oil leakage.

Chapter 6 Gearbox Contents Specifications

General description Removal of gearbox Dismantling - manual gearbox Overhaul - manual gearbox

Refitting the gearbox nog Automatic transmission - removal ... Automatic transmission - overhaul Fault finding - manual transmission

een ...

Fault finding - automatic transmission

Reassembly

= oO OND

aOpwn-

Specifications Manual transmission Gear ratio First Second ithcligees Fourth Reverse

Gearbox

Overall

mph/1000 rpm

3.683 2.263 1.397 1.0 3.692

14.4

4.7

8.8 5.4 3.9

7.6 12-3 Nez

above - 18°C (OOF) SAE 90 EP below - 18°C (O°F) SAE 80 EP 5.3 US pints (2.5 litres) 4.4 Imp pints

Lubricant

Capacity

14.4

...

Gear backlash Input to layshaft First and reverse gears ms Second and third gears ... xe Synchro mesh cone clearance minimum Automatic transmission Gear ratio First Second hinders Reverse

0.001 - 0.004 in (0.03 - 0.10 mm) 0.004 - 0.008 in (0.10 - 0.20 mm) = ...

General description

1 The RX2 can be fitted either with a 4 speed manual gearbox, or with an automatic one of 3 speeds with a torque converter. Both are conventional of their type. 2 The Wankel engine has much the same requirements for its transmission as does a piston engine. The only difference is that the engine speeds are higher. 3 The manual gearbox has synchromesh on all four gears. The floor mounted gear lever has a remote control to bring it back beside the driver. The synchromesh is of a fairly simple baulk ring type, so quite straightforward to work on. The only rare feature is that the casing cover is on the bottom, so the layshaft

must be removed before the mainshaft.

0.031 in (0.8 mm)

Gearbox 2.548 1.458 1.0 2.181

Lubricant Type Capacity ... “ he Torque convertor stall speed Tightening torques Rear bearing plate bolts Main shaft nut

1

0.002 - 0.006 in (0.05 - 0.15 mm)

Overall 9.9

Road speed

Be,

varied by

3.9 8.5

torque convertor

Dexron

R

11.6 US pints (5.5 litres) 9.7 Imp pints 2,400 rpm

7 Ib ft (1.0 Kg m) 170 Ib ft (23 Kg m)

4 The automatic transmission has a torque converter and three speed gearbox. It is the model 3N71B made by the Japanese Automatic Transmission Company. The only variation from normal is that the converter has been designed to suit the Wankel engine’s liking for high speed. So the stall/coupling speed is higher than would be so for a piston engine. The manual range

selector is on the floor. The forward ranges have the usual ‘D’, and also ‘1’ and ‘2’ positions. These lock up the gearbox in first or second gear. ‘2’ should not be selected at a speed faster than 80 mph (130 km/h) or the engine will be run too fast. There is no oil pump on the output shaft, so tow starting is not possible with the automatic transmission. If the car needs a tow on the event of breakdown, the rear axle should be disconnected at the rear axle.

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FIG. 6.2. GEARBOX SELECTOR MECHANISM Fitted bolt Key Remote control cup Reverse plunger detent Detent cap Ball Plunger spring Reverse catch plunger BOBNAGAARWY™ Cover 10 3rd/4th fork bolt 11 Detent cap 72 Cover

13 74 15 16

1st/2nd fork bolt Reverse fork bolt Reverse light switch

17 78 719 20

Reverse Reverse Reverse Detent

1st/2nd fork

fork idler shaft idler cap 21 Detent spring 22 Detent ball

23 1st/2nd selector rod 24 Interlock plunger 25 3rd/4th selector rod 26 Reverse selector rod 27 Interlock and detent cap

Spring cap

Friction piece

-Control Spring

rod

Fig. 6.3. Friction damper of remote control rod

86

Chapter 6/Gearbox

4 Inside the car remove the gear lever. To gain access first remove the four screws holding the console to the tunnel. Lift

7 Take off the nuts holding the rear extension, with spring and flat washers. 8 Lay the gear lever seat on the end of the remote control rod over to the left as far as it will go, to disengage the remote control front end from the selector rods. (photo) 9 Pull the rear housing off. 10 Remove the two small pressed covers from the gearbox casing. 11 Take off the circlip holding the speedometer gear. Take off the gear, catching its locating steel ball. 12 Whilst still with the selectors fitted, engage two gears simultaneously to lock the gearbox, using the two outer most

off the console, pausing if a radio is fitted in it to disconnect all

selectors, reverse and 1st/2nd.

the leads to it. Remove the front bracket for the console from the gearbox tunnel. Peel back the carpet, and tuck it over the handbrake. Remove the six screws holding the rubber boot on the tunnel around the gear lever. Peel back the rubber boot. Undo the four bolts holding the gear lever mounting to the top of the box. (Not the three little ones that just hold the lever into the top). Note the two length of bolts. Put some rag round the remote control gear rod to keep out dirt. Check the plastic cup between the gear lever bottom and the remote control is secure, and will not get lost. 5 From the top of the engine remove the starter motor, after disconnecting its cable and undoing the two nuts and two bolts that hold it. 6 Under the car unplug the reverse light wires high up on the left of the gearbox casing. 7 Undo the speedometer cable from the rear extension housing.

13 Bend back the tab washer under the large nut on the output shaft. Undo the large nut, using a 46 mm AF spanner. Take off the nut and tab washer. 14 Put the gearbox back into neutral. Remove the two caps on the gearbox top, and take out the springs and detent balls that

2

Removal of the gearbox

1 It is possible to remove the gearbox without the engine. It comes out underneath, so will require a pit or hoist, to give space to work. If such space is not available, then it will probably be easier to take out the complete engine and gearbox, as described

in Chapter 1/9. 2 3

Disconnect a battery lead. Drain the gearbox oil; clean and replace the plug.

(photo) 8 9

Remove Unbolt

the pull off spring from the clutch withdrawal fork. the clutch hydraulic cylinder from the clutch

housing. Disengage it from the withdrawal lever and tuck it up Out of the way beside the engine. 10 Remove the run of exhaust pipe (and thermal reactor pipe with mesh grille if fitted) from the exhaust manifold to just in front of the rear axle. 11 Disconnect

the propeller shaft from the rear axle. Undo the

centre shaft bearing. 12 Pull the propeller shaft out of the rear of the gearbox. 13 Support the engine with a jack under the sump, putting a plank of wood between the two to spread the load. 14 Support the gearbox very lightly with another jack. 15 Remove the bracket under the gearbox, by undoing the two nuts holding it to the floor of the car, and the two small nuts holding the mounting rubber to the gearbox casing.

16 Remove

the bolts holding the clutch housing to the engine.

17 Supporting the gearbox by hand, take out its supporting jack. The gearbox is heavy enough to need two people. Pull the gearbox housing backwards to draw the shaft out of the clutch, taking care not to lower the gearbox, lest the shaft through the clutch should take the weight, and damage something. Once clear, lower the gearbox clear.

3

Dismantling the manual gearbox

1 Clean the outside of the casing, and inside the clutch housing. But do not wet the clutch withdrawal bearing. It is-sealed, so cannot be dried out or regreased.

2

Remove

the large bottom cover. Measure the gear back lash

hold the 1st/2nd and 3rd/4th selector rods in gear. (photo) 15 Take out the bolt slanted upwards into the gearbox side, and take out the spring with one ball, the reverse gear detent.

16 Pull off the reverse gear from its shaft on the back of the gearbox, drawing out the selector rod with its fork on the end.

(photos) 17 Undo

the

bolts clamping

the other

two

forks to the rods,

through the two apertures in the casing. Turn the gearbox so the passage for the interlock detent is horizontal. This passage is the continuation of that from which the reverse gear detent ball has just been removed. At this angle the interlock plungers should not fall into the gearbox. 18 Pull out the two remaining selector rods, leaving their forks

loose in the gearbox. (photos) 19 From the casing remove the two interlock plungers from the hole between the passages for the two rods in the housing. These plungers prevent two adjacent rods moving in parallel if the gear lever is not fully over in the correct plane, so the gear lever cannot engage two gears at the same time. 20 Remove the circlip from the rear end of the layshaft, and take off the reverse idler gear. 21 Remove the reverse gear from the mainshaft, with its key. 22 Remove the bolts holding the bearing plate at the rear of the

mainshaft. (photos) 23 Pull out the reverse shaft, which was held by the plate engaging in a slot in the shaft. 24 The next task is to remove the bearings and take out the layshaft and mainshaft. The mainshaft bearings must be taken out before the layshaft can be lifted out of the casing. 25 Take the circlips off the shafts by the bearings. 26 Pull the bearings out of the casing. They are likely to be stiff. For the layshaft a puller with small feet is needed. One can be made up fairly readily. For the mainshaft the presence of the shaft impedes use of a puller. Use of levers needs great care, as there is risk of damaging the end faces of the casing. It is important to keep the bearings straight as they are drawn out. It is possible to start the rear layshaft bearing with a drift from inside the box. 27 The bearings that come most easily should be taken out first. If one proves difficult try another. Once one shaft has both its bearings out, and is free, though it is trapped in the casing till the other is free too, there is scope for careful use of a hammer to drive the other shaft complete with bearings, with a hammer.

and shaft endfloat now, as discussed in Section 4, before starting dismantling.

28 Note, and keep, the shims that come out with each bearing. 29 Once both shafts are free, the mainshaft, with the two

3

selector forks still with it, is left lying in the casing whilst the layshaft is threaded out. Then the forks can be lifted out. 30 Remove the first motion shaft (ie the input shaft) from the front of the mainshaft. Take out the top gear synchromesh ring

Undo the spring clips, and remove the clutch thrust race from

the withdrawal

lever. Unclip and remove

the clutch withdrawal

lever from its pivot in the clutch housing. (photo) 4 Remove the eight nuts holding the clutch housing to the front of the gearbox casing, with their spring and flat washers. 5 Pull off the clutch housing. Note the oil seal for the input

which is now loose. (photo) 31 Taking care none of the synchromesh dog clutch sleeves slide

shaft of the gearbox is in the housing. If a new one is not available take great care as the housing is drawn off. 6 Unbolt the bolt holding the speedometer drive into the rear

off their hubs, tilt the mainshaft, with the gear cluster complete

extension casing and withdraw it. (photo)

washer, the 1st gear wheel and synchro ring. Then take off the

on it, and lift it out of the casing. 32 Take

off

along

the

rear

end

of the

mainshaft

the

thrust

RAEN,

2.1 The gearbox is entirely conventional. A good pit or a lift is needed

2

2.7 The speedometer cable and reverse light wires are easily reached from underneath

2.10b ... and at the joint just in front of the rear axle

3.3a Unclip the clutch withdrawal bear-

2.15 Whilst being undone the weight of

taking off the rear extension

Cars, is undone at the front ...

3.2 Remove the bottom cover and measure

the gearbox must not hang on the shaft through the clutch

the endfloat before dismantling

3.3b Then unclip the lever from its pivot

3.4 The oil seal in the clutch housing

ing from the fork of the lever

3.6 Take out the speedometer drive before

2.10a The exhaust pipe, and the thermal reactor pipe on emissions controlled

should be replaced

3.1 1a Take out the circlip

3.11b Then catch the steel ball that locates the speedometer gear

all 3.12 Select two gears to lock the gears solid; (1/2 and reverse), then slacken

3.14 These are the detents that hold the selector shafts in.

nut On mainshaft

3.15 Their removal is straightforward if the gearbox is tipped up to make them

fall out

(See Fig. 6.2)

Re

3.16a Pull off the reverse idler gear with its selector

oe

aes

3.16b Then the reverse laygear

3.16c comes off

3.18a Pull out

3.18b the two

3.20 The large nut previously loosened can now be taken off, followed by the reverse gearwheel

3.22 Then the mainshaft rear bearing plate

eo

3.17 The two holes give access to the

rods

bolts securing the 1st/2nd and 3rd/ 4th selector

forks to their rods

3.19 Making sure the two interlock plungers are retrieved

89

OO.

@

4)

FIG. 6.4. GEARBOX

MAINSHAFT COMPONENTS

Circlip Key Spring

Clutch hub (1st & 2nd) Clutch sleeve (1st & 2nd) Synchronizer ring (3rd) QARWY™

7

Third gear

8 Second gear 9 Synchronizer ring (2nd) 10 Spring

13 Clutch sleeve (3rd & top) 14 Synchronizer ring (1st)

11 Clutch hub (3rd & top)

715 1st gear bush 76 1st gear 17 Thrust washer

12 Key

18 Shim

19 20 21 22 23 24

Ball bearing Key Reverse gear Lock washer Lock nut Main shaft

Be

Which then

releases the reverse idler

gear shaft

3.27b Once some are out of the way there is scope for driving the others out

3.25 The circlips are next taken off the bearings

3.27a The two bearings of the two shafts

3.30 Once all four bearings are out, the

3.31a Finally the front end of the mainshaft is tipped up

layshaft can be withdrawn

must now be withdrawn

&

90

Chapter 6/Gearbox

complete 1st/2nd synchro unit, keeping the sleeve on its hub. 33 From

the front end of the shaft take off the 3rd gear synchro

ring. Remove the circlip on the mainshaft. Take off the 3rd/4th synchro unit, and then the 3rd gear wheel. 34 If a synchro sleeve should slide off its hub in the struggle to get it off the shaft, note there are three keys fitted into the hub and held in by the sleeve, which lost.

4

Gearbox overhaul - manual

1

If the gearbox has become

will fall out, and should not be

noisy due to general wear, then if

it is possible get an officially overhauled unit. The cost of the many individual components and the problems in ordering so many spare parts make it uneconomic to do it oneself. Also the expertise at the factory enables the shaft endfloat to be set up readily. 2 Whenever the gearbox is dismantled, new oil seals should be fitted at input and output as a matter of course. Also new

3.31b The mainshaft comes out last

gaskets should be used at the front and rear of the casing, and under all covers. 3 Endfloat of the shafts should be measured before the gearbox is dismantled at all. The clutch and the rear extension housings affect the position of the bearings. Endfloat should be between 0.0005 and 0.009 inch (0.01 and 0.23 mm). 4 Gear backlash should also be checked before dismantling. The tolerances are given in the specifications. 5 Once the gearbox has been stripped all parts should be examined. The ball and roller bearings should be free from any marks, and rotate smoothly. The gear teeth should be smooth and shiny. The gear wheels should

6

be a good fit on their bushes.

Check the clearance between the synchromesh rings and their

adjacent clutch teeth on the gear wheel flank. This is dimension ‘A’ in Fig. 6.5. If this is less than the minimum

(0.8 mm)

of 0.031

inch

3.33a Keep all the parts that come off the mainshaft laid out in order

the cone on the gear will be going too deep into the

ring. Even if the ring seats nicely, and not too deep, check that it is not worn so that the oil grooves on its inside have disappeared. If the gearbox has run a high mileage then new rings are sure to be needed. 7 Fit the front end of the propeller shaft into the rear extension housing, and check the clearance of the bearing.

5

Gearbox reassembly

1

Collect all the parts in order, and all clean. An oil can filled

with gearbox oil (SAE 90 EP) will be needed. All the gears and their bushes must must be clean and 2 Assemble the clutch sleeves on synchro rings and

3

From

be lubricated before assembly. The work area free from dust. gear-engaging synchromesh units, putting the their hubs, with the three pawils inside. Oil the put them in the cones. (photo)

the rear end of the mainshaft

wheel, then

put on the second gear

the 1st/2nd synchro assembly.

From

the front end

3.33b Try and get the synchromesh units off without the sleeve of the synchromesh dog - clutch sliding off its hub

put on the third gear wheel, and the 3rd/4th synchro assembly, and then the circlip. 4 From the rear put on the 1st gear wheel, and the thrust washer. 5 Thread the mainshaft assembly into the casing (the rear end can be recognised by the holes for the selectors). 6 Put the top gear synchro ring into the cone in its clutch, and fit the input shaft mainshaft spigot.

7

through

the

front

of the casing, onto

the

Put the 1st/2nd and 3rd/4th selector forks into position on

their clutch sleeves, with the holes for the selector rods in the correct position (see the sectioned picture of the gearbox, Fig. 6.2. and photo 5.7). 8 Leave for now the complete mainshaft assembly loose in the casing.

9 Put the layshaft into position in the casing, but still without its bearings. 10 Fit the rear main

bearing onto

the mainshaft. Tap it down

3.34 If it does come off, make sure the three little keys are not lost. Refer to Figs. 6.1 and 6.4

ONES

5.7 The mainshaft assembly with the 1st/

5.2 Before putting the shafts in the box, get everything together, efer to Figs

2nd and 3rd/4th selector forks must

6.1 and 6.4

5.11 With both shafts put in loose, their bearings can be fitted in turn

be laid in the casing, the forks being

as shown in Fig. 6.2

5.14 The interlock plungers must go in between the rods

5.13 When fitting the selector rods look at Fig. 6.2 to see where the interlock plungers go

5.21 The interlock plungers allow the two outside rods to engage gears simultaneously to lock the box

the shaft and then into the casing, supporting the front end of the shaft

by hand to keep it straight. Use a long tube over the

shaft when

driving the bearing down the shaft, to work on the

inner race. Once getting it into the casing, tap round the outer race with a hammer, gently, and working all the way around. 11 Similarly fit the front mainshaft bearing, not forgetting its shim. Recheck that the rear bearing is still in place. 12 Fit the front bearing to the layshaft, with its shim. Then fit the rear one. Check the two shafts rotate freely, and that all bearings are fully home. There should be a trace of end float in the shafts. Only use a soft hammer on the ends of the shafts, lest their splines be damaged.

Fig. 6.5. When worn the synchromesh baulk ring will seat too close to the gear wheel. The dimension ‘A’ must not be less

than 0.031 inch (0.8 mm)

13 Slide in the 1st/2nd selector rod (the one with only one slot for an interlock detent). The correct way

lock detent slot to fork with the special 14 Put an interlock between the 1st/2nd

round is for the inter-

be towards the 3rd/4th rod. Lock it to the bolt. (photo) detent plunger into the passage in the casing and 3rd/4th rods. (photo)

15 Slide in the 3rd/4th rod, with the open end of its fork for the gear lever remote control inwards, and bolt it to its fork. 16 Fit the reverse gear shaft into the rear of the box. Fit the rear main bearing locking plate. 17 Put the reverse gear onto the splines on the layshaft, rounded end of the teeth outwards, and fit its circlip.

18 Put the reverse gear woodruff key into the mainshaft, and fit the gear.

19 Drop

in the

second

interlock

plunger

above

the 3rd/4th

selector rod. 20 Slide into the box the reverse selector rod, with the reverse idler gear in the fork, and guide the gear onto its shaft.

21 Engage 1st and reverse gears to lock the box. (photo) 22 Fit the tab washer and nut to the mainshaft.

6.6 Remember to fill it up with oil

92

Chapter 6/Gearbox to understand the makers manual, and should work from that. If not, a reconditioned unit should be fitted.

23 Disengage the gears. 24 Fit the reverse gear detent ball, spring, and retaining bolt.

25 Fit the 1st/2nd and 3rd/4th detent balls, springs, and capped nuts. 26 Fit the two small cover plates by the selector forks, using new gaskets, and putting on the long stud the reverse light wire’s clip, and second nut. 27 Fit the speedometer drive gear with its locating ball, and circlip. 28 Fit the bottom cover (drain plug at the rear end). Stand the gearbox the right way up. 29 Fit the oil seal to the rear extension (and the new bush if it is

9

Fault-finding - manual transmission

1 The aim of fault-finding on the gearbox is to decide if it has to be removed from the car for repair. Very little can be done

being replaced).

with it in place. 2 If a gear cannot be engaged, or when engaged, does not work, then the gearbox must be removed and stripped.

30 Put a new gasket in place on the rear of the gearbox main casing, and slide on the rear extension, putting the remote control over to the left as far as it will go to clear the selectors. Fit the cable clip on the stud in line with the reverse light switch. 31 Fit the gear lever temporarily, and check all gears can be selected, and the gearbox turns satisfactorily. Remove the lever again.

taken

32 Fit the clutch housing to the gearbox, with the new oil seal in place, and using a new gasket. 33 Put some grease on the pivot for the clutch withdrawal lever. 34 Smear a little grease on the inside of the withdrawal race, where it will mount on the housing. Do not immerse the bearing in cleaning fluid, as it is sealed, and cannot be dried out or regreased. 35 Clip the withdrawal race into the fork on the lever, and put the lever into place, the bearing on the shaft, and the lever on the pivot. 36 Fit the speedometer cable drive into the rear extension.

6

Refitting the gearbox

1 Wipe the input shaft dry where it goes through the clutch. If it is oiled or greased after a time it will become sticky, so the

3 If an unusual noise, or rough running of the box comes on suddenly, or over a short mileage, then this indicates a serious defect, and again the gearbox should be dismantled. 4 If there is a need to continue to drive the car when something serious is amiss, then the bottom plate can be taken off. This should allow the damage to be assessed, and any broken bits out. If metal chips have been thrashed

round everywhere

by the oil they will have got into the bearings, and could cause damage. If having to swill out the gearbox, and SAE 90 EP oil is not available, provided the car is driven gently, engine oil can be used. 5 If noises gradually get worse after the car has done a high mileage, then it will probably carry on for a long time more. Annoyance with the noise is likely to be the main reason for stripping the gearbox. No one item will probably be blameable for the noise, and all the bearings will want replacement. 6 After a high mileage the synchrormmesh may get weak as the rings get polished. Changes will be slow, but should still not grate the teeth, because of the baulking action of the synchro ring. With worn synchromesh, changes up will probably still be satisfactory, but it will become better to double-declutch when changing down. To strip a gearbox for worn synchromesh means taking On a complete overhaul, as many other components will be worn too, and a satisfactory job will only be done if it is thorough.

clutch will drag.

2 Put a trace of molybdenum disulphide grease in the spigot bearing at the rear of the crankshaft. 3 If the engine is out of the car, refit the gearbox to the engine as described in Chapter 1/33. 4 If the gearbox has been removed leaving the engine in the car, carry the gearbox under of its removal. 5 The gearbox must be to the engine, so that no through the clutch. Put

the car. Replacement

is then the reverse

supported after it has been offered up weight is allowed to hang on the shaft in the bolt at the top holding it to the engine, and tighten it finger tight. Put the jack under the gearbox. Sort out the various lengths of bolts to their respective holes. Fit all and tighten them evenly, releasing the jack under the gearbox as the bolts take the weight. Refit the mounting bracket under the gearbox after the latter is fixed to the engine.

6

Fill the gearbox with oil. (photo)

7

Automatic transmission - removal and replacement

1 The general instructions for the manual gearbox apply, the differences being in the gear lever and range selector mechanism. 2 Note the additional wiring for the starter inhibitor switch, and the kick-down control.

8 1

If there has been failure in the transmission

will

have

been

worn

1 Faults can be divided into three groups. First there is the type that is the failure of a major component, such as one of the gears or the torque converter. Then there is failure of the oil pressure system, which will give many symptoms. Finally there is failure of the external controls and links. 2 If slippage of the gears takes place, their clutches will wear rapidly. Minor slippage always occurs as the gears change, but if pressure is low or things are out of adjustment, the change will be made too slowly, and slippage may go on for over a second, which is excessive. In extreme cases slippage may occur in normal driving. Slippage will show itself when driving hard, keeping the engine well above 3,000 rpm, so the converter will have coupled. 3 the be are

The functioning of the converter, and within broad limits, oil pressure, can be checked by doing a stall test. This should

practised once or twice when the car is fit so that its results known. Have the car warmed up, but not hot. Choose a clear

- level or uphill stretch

as well

then a number

as those

of

giving the

symptoms of failure.

2 The overhaul! needs expertise and facilities beyond the scope of a book such as this to describe. If you are a mechanic competent to deal with the transmission, then you will be able

of road. Engage ’D’. Release the parking

brake, but apply the foot brake hard with the left foot. Press the accelerator to the floor. Note what engine speed is achieved on the tachometer. Only hold the accelerator down long enough for the reading to steady. Never do so for more than four seconds.

All the engine power

Automatic transmission - overhaul

components

10 Fault-finding - automatic transmission

is being dissipated in the converter, and it

will quickly overheat. The engine speed should be about 2,400 rpm. If the engine speed is abnormally high, the converter is slipping. This could be either a converter fault, or low oil pressure. If the stall speed is abnormally low, it indicates a converter fault. 4 Low oil pressure shown up in a converter stall test will also usually give sluggish gear changes and much slipping.

Chapter 7 Propeller shaft Contents Specifications General description Removal and replacement Universal joint inspection

1 2 3

Universal joint dismantling ... Universal joint reassembly ... Centre bearing

Specifications

Length: front section rear section Outer diameter -

1

Sh a es

Be a is

BS st a8

ig a oe

eu ee a5

502 mm (19.76 in) 719 mm (28.31 in) 508 mm (2.0 in)

Permissible out of balance: Front andrear joints... Centre joint sie eh

was se

ees ies

See ss

ef ee

20 gm cm at 4000 rpm 12.5 gm cm at 4000 rpm

Permissible run-out ... Tightening torque...

ae m

sk cs

a =

a a

0.4 mm (0.016 in) 3.0 Kg m (20 |b ft)

os a

General description

Drive

is transmitted

from

the gearbox

to the rear axle by

means of a tubular propeller shaft split into two halves and supported at the centre by a rubber mounted bearing.

Fitted to the front, centre and rear of the propeller shaft are universal joints which allow for vertical movement axle and slight movement of the complete power

of the rear unit on its

rubber mountings. Each universal joint comprises a four legged centre spider, four needir roller bearings and two yokes. Fore and aft movement of the rear axle is absorbed by a

sliding spline at the end of the extension of the gearbox mainshaft, which fits into the propeller shaft. The propeller shaft in its bush fits into the gearbox rear extension, and is supported by a plain bush bearing. The yoke flange of the rear universal joint is fitted to the differential pinion flange with four bolts, spring washers and nuts.

2

Propeller shaft - removal and replacement

1 Jack up the rear of the car and support on firmly based stands. Alternatively position the rear of the car on a ramp. Chock the front wheels.

2

Support

the weight

of the rear propeller shaft. Undo

and

remove the four axle end flange nuts and bolts. 3 Undo the bolts, holding the centre bracket to the floor of the

car. 4 Pull the shaft back out of the gearbox rear extension, then lower it, threading the bracket along to clear the exhaust. 5 When refitting the propeller shaft, make sure the front end is clean, then enter it very carefully into the gearbox, so that the lips of the oil seal are not damaged.

6 Clean the axle flange, and then tighten the bolts securing the shaft to it gradually, wriggling the shaft about to seat the two flanges together accurately.

Fig. 7.1. The centre support for the two piece propeller shaft (exhaust removed)

4 5 6

94

Chapter 7/Propeller shaft 4

3

1 Wear in the needle roller bearings is characterised by vibration in the transmission, ‘clonks’ on taking up the drive, and in extreme cases of lack of lubrication, metallic squeaking, and ultimately grating and shrieking sounds as the bearings break up. lf a bearing breaks up at speed it could be lethal. So they should be changed in good time. 2 It is easy to check if the needle roller bearings are worn with the propeller shaft in position, by trying to turn the shaft wi*h one hand, the other hand holding the rear axle flange when the rear universal is being checked, and the front half coupling when the front universal is being checked. Any movement between the and

the

Take out the seals. Remove

the circlip. Then drive the bear-

ing out of the support. 5 Fit the new bearing by driving it into the support with some

Universal joints - inspection

propeller

shaft

indicative

of considerable wear.

front

and

the

rear

half

couplings

tubing. Fit the circlip. Carefully fit the seals, lips inwards. Refit the yoke in its original position

is

If worn, the old bearings and

spiders will have to be discarded and a repair kit, comprising new universal joint spiders, bearings, oil seals, and retainers

purchased. Check also by trying to lift the shaft and noticing any movement in the joints. 3 Examine the propeller shaft spline for wear. If necessary to purchase a new front half coupling, are badly worn, an exchange propeller shaft. It is fit oversize bearings and journals to the trunnion

4

Universal joints - dismantling

1

Clean

away

all traces

of dirt and

worn it will be or if the yokes not possible to bearing holes.

grease from the circlips

Fig. 7.2. The flange joining the rear of the shaft to the differential. At the front a sliding joint is used

located on the ends of the bearing cups, and remove the clips by Pressing their open ends together with a pair of pliers and lever them out with a screwdriver. NOTE: If they are difficult to remove, tap the bearing cup face resting on top of the spider with a mallet which will ease the pressure on the circlip.

2 Take off the bearing cups on the propeller shaft yoke. To do this select two sockets from a socket spanner set, one large enough to fit completely over the bearing cup and the other smaller than the bearing cup. 3 Open the jaws of the vice and with the sockets opposite each other endthe UJ _ in between tighten the vice and so force the narrower socket to move the opposite cup partially out of the yoke into the larger socket. 4 Remove the cup with a pair of pliers. Remove the opposite cup, and then free the propeller shaft. 5 To remove the remaining two cups now repeat the instructions in paragraph 3, or use a socket and hammer.

1

3

4

$

6

FIG. 7.3. AN EXPLODED VIEW OF A UNIVERSAL JOINT 5

Universal joints - reassembly

1 Thoroughly clean out the yokes and journals. 2 Fit new oil seals and retainers on the spider journals, place the spider on the propeller shaft yoke, and assemble the needle

rollers

in the bearing

races

with

the assistance

of some

7 2 3

Circlip Bearing cup Needle rollers

4 5 6

Washer Seal Spider

thin

grease. Fill each bearing about a third full with general purpose grease such as Castrol LM, and fill the grease holes in the journal

spider making sure all air bubbles are eliminated. 3 Refit the bearing cups on the spider and tap the bearings home so they lie squarely in position. Replace the circlips.

4

Circlips of varying thickness are available to get a snug fit.

6

Centre bearing

1 Wear in the bearing, or softness of the rubber support, will show as juddering in the drive when moving off or accelerating hard on a slippery surface. 2 To replace the bearing remove the complete shaft as described in Section 2. Then dismantle the shaft at the centre universal joint, as described in Section 4, Once the universal joint is Out of the way, a spanner can be put on the nut securing the yoke to the front part of the shaft. Take off the yoke. Mark its position for reassembly.

3

Pull the bearing assembly off the shaft.

Fig. 7.4. The shaft can be unbolted at the centre after removal

Chapter 8 Rear axle Contents Specifications

General description Lubrication Hub bearing construction Removal of half shaft and hub beariige Replacing the half shaft and bearing ... Removal of the final drive Dismantling the final drive and differential Overhaul of the final drive and differential

1 2 3 4 5 6 7 8

Meshing the crownwheel and pinion

ato

Adjusting the pinion position ms Fitting the pinion- preloading the bearings: Reassembling the differential By ts Adjusting the crownwheel ... en me Refitting the final drive = es = Fault finding - hub bearing ... ase Pe Fault finding - final drive noise _... css

= fs as Ser as wis ues

Specifications Type

Gear ratio Lubricant

Hs

ay,

aa

eee

es

aes

5

ats

Semi-floating, hypoid final drive

oe “on

= -

A ts

a Ao

3 iss

Me ee

= anc

Be/ (7 O) Above - 18°C (O°F) SAE 90 EP

Hub bearing retainer plate clearance: less than Pinion end to diff centre line... as ‘ied Pinion to crownwheel backlash 7 a

“ #2 me

8 eee 6

Below - 18°C (O°F) SAE 80 EP Capacity 2.5 US pints (1.2 litre) 2.1 Imp pints 0.1 mm (0.0039 in) 90 mm + 0.25 mm (3.543 in + 0.001 in) 0.17 - 0.19 mm (0.0067 - 0.0075 in)

Side gear to planet backlash: less than Pinion bearing preload ... ie Ae Distance across differential caps oe Crownwheel run out: less than... sa

aS Pe oe ne

ae an bos .:

af 46 ce ea

0.1 mm (0.004 in) 9-14 Kgcm (8 - 12 Ib in) 185.5 mm (7.306 in) C.1 mm (0.0039 in)

Pinion positioning spacers

a

at

60

Side gear thrust washer ...

B06

Re

Tightening torques: Drive flange to pinion shaft

ree

oe

Ss

nas

ee

Identification mark

thickness

08

3.08 mm (0.1213 in)

11 14

3.11 mm (0.1224 in) 3.14 mm (0.1236 in)

17

3.17 mm (0.1248 in)

20 23 26 29 32 35

3.20 3.23 3.26 3.29 3.32 3.35

38 41 44 47 0 1 2

3.38 mm (0.1331 in) 3.41 mm (0.1343 in)

os

ies

aes

ies

110 Ib ft (15.0 Kg m)

Crownwheel to differential case...

-

ae

385

45 |b ft (6.0 Kg m)

Differential bearing plug...

rs

ee

ons

15 |b ft (2.0 kg m)

bee

mm mm mm mm mm mm

(0.1260 (0.1271 (0.1283 (0.1295 (0.1307 (0.1319

in) in) in) in) in) in)

3.44 mm (0.1354 in)

3.47 mm 2.0 mm 2.1 mm 2.2 mm

(0.1366 in) (0.0787 in) (0.0827 in) (0.0866 in)

9

a = waa aes ae se are

10 11 2 13 14 15 16

96

1.

Chapter 8/Rear axle

General introduction

1 The rear axle is conventional. In the centre of the casing is the final drive that turns the drive from the propeller shaft through 90° and gives it a last gear reduction. Also in the centre is the differential to allow the two wheels to go at different speeds, yet share the torque equally between them. Half shafts carry the drive from the differential out to both hubs. 2 The build up of the hubs and half shafts is of the type known as ‘semi-floating’. This makes work on the shafts or bearings difficult, and especially so if the special half-shaft withdrawing tool is not available. 3 If there is a definite failure of a component in the axle then action must be taken, and though it is difficult to work on, it can be done without special tools. However if the final drive is noisy, it is difficult to ensure than an overhaul without the special tools, and without practice in meshing the crown wheel and pinion, will give the improvement required. Fitting a new hub bearing requires a press of 3 tons force! If a hub bearing retaining collar is incorrectly fitted, the whole wheel and drum assembly could move out, and finally come off. 4 The brakes on the rear axle. are dealt with in Chapter 9. The suspension attaching the rear axle to the car is in Chapter 9. The suspension attaching the rear axle to the car is in Chapter Ue?

does not 6 Now done by which a

strain the hydraulic pipe. the bearing must be pulled out of the axle casing. It is pulling the end of the half shaft. But there is nothing on conventional puller can act. The normal tool is a long rod with a flange similar to that on the end of the halfshaft. On it is mounted a heavy weight. This weight is thrown along the rod. It hits the far end, and the impact drives out the shaft with the bearing. This type of axle is quite common. A puller from another make of car may be available locally, and an adaptor plate could fit it to the Mazda’s half shaft flange. Without it the necessary pull must be applied another way. A thick piece of steel bar some 3 ft long can be drilled to bolt across the half shaft flange. This will allow a firm grip to be taken with both hands,

Lubrication

1 As the final drive is by a hypoid bevel the use of the correct type of extreme pressure lubricant is important. 2 Some manufacturers do not call for any oil changes for their final drives, and the oil is reputed to last the life of the axle. Indeed, some cars have no drain plug.

3 The additives that give the oil its extreme pressure qualities do get used up. Also with time the oil absorbs damp. Bearings corrode, pitting their running surface. It is probably fairer to put the phrase the other way, and say the axle lasts the life of the oil. As the oil is easy to change, but the axle very difficult, it is

suggested that Toyo Kogyo are quite right to recommend changes every 12,000 miles, and these should be done, it being especially timely to do so after the winter, when damp will have been absorbed in the oil.

feet

are

braced

against the rear

suspension.

trace of side movement. If it is being refitted, grease should be wiped liberally on it to keep out the dirt. 8 Prise the oil seal out of the end of the axle casing. This should be replaced as a matter of course having got so far. 9 If the bearing is to be changed the collar must be got off the half shaft. This should be done by pressing, but the load needed will be in the order of 5 tons weight. The press load must not 10 tons.

If it does

not shift, or if no press suitable

is

available, then the collar must be cut off. This is done by cutting in straight towards the centre with a cold chisel. This is the time when an experienced person can give guidance if you have never done it before. It is quite simple, though slow. A good quality, wide, chisel is needed. Take care not to damage the half shaft, though as it is quite fat at this point, a minor burr can be filed Out later without weakening the shaft, but a large mark will mean the new collar will be too loose. 10 Whilst working on the half shaft ensure no scratches or marks are made on the thinnest part, or these will initiate a crack and the shaft will break from fatigue. 11 If the car has done a mileage in excess of 150,000 it is probably worth fitting new half shafts instead of struggling to get the bearing off. The retaining plate can then be got off by sawing up the shaft if one of these, which will be quite cheap, is not available. 5

3

the

person pulls very hard, two more should hit the ends of the bar with hammers, simultaneously. 7 Once the shaft is out, the parts should all be cleaned again. Once this has been done the decision must be made if the bearing is to be changed. It must rotate very smoothly, with only a

exceed 2

whilst

Make sure the car is very firm on the jack and stands. Whilst one

Replacing the half shaft and hub bearing

Hub bearing construction

1 The single ball bearing is mounted on the half shaft, and its outer race inside the axle casing. The wheel and brake drum are hung outboard on the end of the shaft. 2 The bearing outer race is held in the casing by a plate outside the brake backing plate. 3 The half shaft is held in the inner race by a collar that is an interference fit on the shaft. 4 To remove the bearing, the half shaft is removed as described in the next Section.

1 Fit the new oil seal to the axle housing, greasing it first, and tapping it carefully and evenly in, the lips inwards. (The seal is to

keep the axle oil in the casing). 2 Measure the thickness of the new bearing outer race, and compare it with that of the old one. Change the thickness of the bearing retainer plate shims by this difference. Shims are avail-

able in thicknesses of 0.1 and 0.4 mm (0.004 and 0.016 inch). 3 Fit the bearing retainer plate and shims on the half shaft. 4 Fit the bearing flange on the shaft.

spacer,

bevelled

corner

first, down

to the

5 Grease the bearing. Fit it on the shaft with the sealed side towards the shaft’s flange. 4

Removal of half shaft and hub bearing

1

Jack up the rear of the car, add firm extra stands, and chock

If a force less than 3 tons (long tons of 2240 Ib), presses it on

the front wheel. 2 Remove the wheel. Take off the brake drum. 3 Wash the whole area around the brakes and the end of the axle casing very thoroughly. A lot of water and detergent is best, to get all road grit away. In particular, there must be no dirt left that could work its way between the brake backplate and the end of the axle casing when these are undone. 4 Remove the brake shoes as described in Chapter 9. 5 Remove the four nuts holding the brake backplate and bearing retainer to the axle casing. Break the joint between the retaining plate and the backplate. Take care the brake backplate

remove it and try another. 7 Without a strong press again ingenuity must be used. But then the force needed to get the collar on will not be known, so there is risk that the half shaft will pull out of the collar. Apart from a proper press, the best method is to put the half shaft in a freezer overnight. Put the collar in a domestic oven for about half an hour. Do not exceed a temperature of 200°C. Quickly

6 Fit the new collar into place, and press it down the shaft till the bearing is held up against the spacer at the end of the shaft.

put the hot collar on the cold shaft, when it should drive on reasonably readily, resting the collar on a support, and

hammering the end of the shaft.

8

Refit the shaft assembly

to the car. The inner end of the

97

FIG. 8.1. REAR AXLE CASING AND SHAFT COMPONENTS Axle casing Bracket for Panhard rod Studs for final drive carrier Studs for final drive carrier

Oil filler/level and drain QAGMYs plugs

6

Oil filler/level and drain plugs

11 Half shaft 12 Bearing retainer plate

17 Shim 78 Oil seal

7 8 9 70

Breather Breather Breather Breather

73 Bearing 74 Collar 15 Spacer

19 Bolt, washer and nut securing

16 Gasket

brake back plate and retainer

20 Bolt, washer and nut securing brake back plate and retainer

Chapter 8/Rear axle

98

shaft must be guided into the splines of the differential side gear.

Take care not to damage the oil seal. Line up the bearing with the casing. Drive it in by hammering the flange on the end of the half shaft. Take care the bearing retainer and back plate do not get trapped. Get them onto their bolts as soon as possible. 9 Bolt up the back plate and bearing retainer. Check the hub turns freely.

10 Reassemble the brakes. 11 Check the rear axle oil level. 12 Road test the car. If possible do some hard cornering on a deserted open area where any weakness of the collar on the shaft will be shown up without danger. The relationship of brake drum to backplate will show if the shaft is working out. This should be regularly checked for some time.

6

Removal of the final drive

1 Jack up the car and support it firmly on extra supports. 2 Drain the rear axle oil. Refit the drain plug. 3 Remove both half-shafts as described in Section 4. 4 Uncouple the propeller shaft from the flange on the final drive pinion by removing the four nuts and bolts. 5 Clean the outside of the axle casing around the joint for the final drive carrier, so no dirt can fall in when the two are pared. 6 Undo evenly the nuts round the joint between the axle casing and the final drive carrier. 7 Lift the final drive carrier forward off the studs.

7

Dismantling the final drive and differential

1 Clean the outside of the carrier. 2 Mark the two differential bearing caps, and the adjacent part of the carrier. Mark the differential bearing adjusters. Then all can be reassembled in the same place. 3 Remove the adjuster lock plates from both bearing caps.

muddled up. They must all go back to the same one unless replaced. Leave the inner races on the differential case for now.

Unlock the tabs and undo the bolts holding the crown wheel

to the differential case, and take off the crown wheel.

8 From the side of the differential case where were the heads of the crown wheel bolts, drive out the pin locking the planet Pinion shaft, using a long thin drift. If it is reluctant to go, clean up the other end of the hole, which will have been burred over to lock it in. 9 Remove the planets’ shaft. Rotate the side bevel gears to bring the planet pinions round to the holes in the differential

case, and extract them.

should not exceed 0.3 mm (0.012 inch). 7

Inspect the surface on the collar of the flange where the oil

seal runs. It must be flawless. 8 If the bearings are to be replaced press the two outer races out of the carrier, and pull the two inner races off the differential case.

9

Meshing the crown wheel with the pinion

1 The pinion must be mounted in the bearing in the differential carrier in the correct fore and aft position, so that its teeth will be lined up correctly with those of the crown wheel. 2 Then the crown wheel must be moved laterally to get the correct depth of mesh for the teeth, with the correct backlash. 3 Finally, all the bearings must be under the proper preload, so the two gears stay in their correct mating positions when under running stress.

4 Slacken the bearing cap bolts so that the bearing will just be free to shift inside. 5 Back off both bearing adjuster locking plates two serrations to relieve the preload (one is a left hand thread) . 6 Remove the bearing caps. Lift the differential assembly out of the carrier. Do not get the bearing outer races and rollers

7

2 New oil seals should be fitted anyway at the flange on the Pinion, and for both hubs. 3 A new crushable spacer will be needed for the pinion bearings. 4 Examine all other parts for damage. All the bearing rollers and races should be shinv. not discoloured or pitted. 5 All gear teeth should be shiny, without chips, scores, or pitting. If the axle has been noisy then it is difficult to diagnose for sure whether the cause is the differential bearings, or the crown wheel and pinion. If the car has done a high mileage, fitting new bearings to an old crown wheel and pinion is likely to be noisy, as the latter will not go back quite in the same place. So it would be advisable to replace the bearings and crown wheel with pinion. The side gears and their planet pinions should not need replacement, though new, thicker thrust washers will probably be needed. See Section 12. The crown wheel and pinion must always be replaced as a pair. 6 Check the splines in the side gears and on the half shafts. Play

,

10 Take out the side gears with their thrust washers. 11 Remove the nut holding the drive flange for the propeller shaft to the pinion shaft. It will be necessary to rig up a holder for the flange using two of the bolt holes.

12 Pull off the flange. 13 Drive out the pinion, by using a soft hammer on the flange end of the shaft. The inner race and rollers of the rear bearing will come with it. 14 Remove the oil seal and the inner race of the front bearing from the carrier. Take out the crushable spacer. 15 Leave the two outer races for the bearings in the carrier for now.

10 Adjusting the pinion position 1

The standard distance between

centre line of the distance is adjusted the rear bearing and difficult to measure

the end of the pinion and the

crown wheel is 90 mm by varying thicknesses the back shoulder of the the distance directly. So

+ 0.025 mm. This of spacers between pinion. It would be if the assumption is

made that the pinion was originally correctly set, then new parts

can be installed and their position set by measuring how much they differ in size from the old ones. 2 Mazda’s official way is to use special gauges. Ideally use these, with the makers instructions for them. The method that follows is a way to get by without them. 3 Read on the rear face of the old and new pinions the plus or minus reading, in hundreths of millimetres. This is their individual variation from standard. Work out the difference between the two, either positive or negative. 4 Place the old and new rear pinion bearings side by side ona surface table, or a sheet of glass. Measure the difference in height. If the new bearing is higher than the old, the difference must be subtracted; it will be a negative factor: and vice versa. 5 Read off the old spacer collar that goes just behind the pinion, its mark, or measure its thickness with a micrometer. (See the specifications at the beginning of the Chapter). 6 The spacer required for the new parts must be different in thickness from the old by the amount calculated in paragraphs 3

and 4, to account for the variation in pinion and rear bearing.

11 Fitting the pinion and adjusting the preload 8

1

Overhaul of the final drive and differentiai

Put the new spacer on the pinion, and then the bearing inner

race. Fit the pinion with the bearings, and the outer race if the

1 Now that the assembly is components can all be checked.

dismantled

sufficiently,

the

bearing has been renewed, into the carrier. 3 Put anew collapsible spacer onto the pinion shaft.

FIG. 8.2. HUB SECTION, SHOWING ALSO THE MAXIMUM CLEARANCE BETWEEN THE BACK PLATE AND THE CASING 1

Spacer

2 Axle casing 3 Half-shaft 4 Bearing 5 Oil seal 6 Collar See also Fig. 11.1b.

(0, 004 in)

FIG. 8.3. FINAL DRIVE PLAN VIEW 7 2 3 4 5

Nut Flange Oil seal Front pinion bearing Collapsible spacer

6 7 8 9

Rear pinion bearing Spacer for adjusting the pinion Pinion Final drive carrier

10 11 12 13 14

Adjuster Differential bearing Differential case Thrust washer Planet pinion shaft

715 76 17 18

Lock pin Crown wheel Planet pinion Side bevel gear

100 4

Chapter 8/Rear axle Place the front pinion bearing in place, and drive it onto its

seat. 5 Grease the new oil seal, and tap it very gently into place, lips inwards. 6 Grease the splines of the flange, and fit it on the end of the Pinion shaft, and tap it into place. 7 Fit the washer and nut, but do not tighten them yet. 8 Check the torque needed to turn the pinion in its bearings without preload, against the drag of the bearings and the oil seal. This will be too delicate for a torque wrench to measure. A balance device can be made up bolted to the flange. A bar should be put across symetrically, and either pulled with a spring balance, or weights hung on it one or two feet out, to ease the mathematics. 9 Now tighten the flange nut gradually, turning the pinion shaft to allow the bearings to roll into position, and noting the drag due to preload of the bearings. The nut should be tightened to a torque of 94 Ibf ft (13 kg m). The spacer will then automatically give the correct preload. At this the bearing should have drag of 8 - 12 Ibf in (9 - 14 kg cm). If the nut has to be slackened off the crushable spacer will not restore itself, and wil!

have to be replaced, so this tightening must be done cautiously.

12 Reassembling the differential 1 Put the side gears, with standard thrust washers, into the differential case. The oil grooves in the thrust washers must be towards the side gears. 2 Put in the planet gears, exactly 180° apart, and move them into position by the side gears. Fit their shaft, but do not yet lock it into position. 3 Check the backlash between the side and planet gears. It

should be zero to 0.1 mm (0.004 inch). If too much fit a thicker thrust washer. 4 Then insert the lock pin to the planet shaft, staking it by burring over its hole with a punch. 5. Put the crown wheel on the differential case, and tighten the

bolts gradually and evenly to a torque of 45 Ibf ft (6.0 Ig m). There are two kinds of bolts, so use those that fit the holes in the case. Do not bend up the tabs to lock the bolts yet.

6

Put the bearings on the ends of the differential case. If using

old parts make sure they all go back in the same place. 7 Lift the differential into place on the carrier. Get the marks for backlash adjustment on the faces of the pinion and crown wheel aligned to each other. 8 Install the adjusters in their respective sides. Note one is a left hand thread. 9 Put on the bearing caps, the same side as they were before. Fit their bolts, but only finger tight. 10 Move the adjusters so that end float in the bearings is eliminated, turning the crown wheel to and fro to let the bearing roll into position, and moving the appropriate adjuster so that a

small amount of backlash is maintained between the two gears. 11 Tighten gently with a spanner one of the bearing cap bolts on each side. 12 Rotate the differential in its bearings to check the crown wheel runs true. Preferably its run-out should be checked with a

dial gauge. It should be less than 0.1 mm

gauges, probably cut into strips, will have to be slid between the gear teeth. The differential should be moved across to get the required backlash by moving both adjuster rings an equal amount. The backlash should be 0.0067 to 0.0075 inch (0.17 to

0.19 mm). 2

Now

preload

the bearings

by tightening both adjusters an

equal amount. The preload is correct when the bearing caps are

185.5 mm (7.306 inch) apart across the span measured by a huge micrometer gauge between the special measuring points on the outside of the bearing caps. These points are offset, the distance measured is slightly skewed to the differential centre line. As a guide the bearjng adjusters will each need to be tightened about One serration, or just a little more to line up the locking plate with a serration, from the position where bearing end float was eliminated.

3

Now tighten the bearing cap bolts to 30 Ibf ft (4.0 kg m).

4

Smear some engineers blue or red lead on the front and back

of about six teeth on the crown wheel. Then rotate the pinion a few times both ways to spread the marker out on the teeth. The marker should give an oval patch where the teeth touch. The mating point should be half way between the root and tip of the

tooth. It should also be half way along the length of the tooth from toe to heel. But a trace off centre here is alright provided it is towards the toe end of the tooth, towards the centre of the crown wheel. If the marking is wrong the thickness of spacer behind the pinion, or the crownwheel backlash would appear to be wrong, and must be rechecked. 5

Fit the differential bearing adjuster lock plates to the caps.

14 Refitting the final drive

1

Fit a new gasket to the axle casing.

2 Fit the final drive in place, and tighten a nut at the top gently first, to hold the carrier upright in the axle casing. Fit and tighten all the nuts. 3 Connect the propeller shaft. Whilst tightening its nuts wriggle it about to ensure it seats in well on the flange. 4 Refit the half shafts as described in Section 5. 5 Refill the axle with oil. 6 If a newcrown wheel and pinion has been fitted, they should be allowed time to polish up their teeth before being used hard. Avoid use of full torque in low gears, or very high speed. 7 Change the oil after 500 miles to wash out any dirt that

might have got in during the work, particularly whilst the axle casing was open, and to get rid of metal particles worn

off new

gear teeth.

15 Fault-finding - hub bearing check 1 The hubs should be checked for rim-rock. 2 Park the car on level ground, in gear (or ‘P’), and !eave the handbrake off. 3 Grip the top of the wheel with both hands and rock it vehemently to and fro. Any rock in the bearings will be felt, or heard. Only a trace is permissible.

(0.0039 inch). If it is

greater, take out the differential, and remove

the crown

wheel

16 Fault-finding - final drive noise diagnosis

from the case. Check there are no burrs or dirt spoiling the seat between the two. If all was in order, try moving the crownwheel round to another position, and fit it again, and remeasure the run-Out. When the run-out is satisfactory, bend up the locking tabs on the crown wheel securing bolts. Then adjust the

backlash.

13 Adjusting the crown wheel 1

The backtash should be checked with a dial gauge, which can

rest On

an end

of a tooth, whilst the crown

and fro. It should

whee!

is moved

to

be possible to borrow one. Without it feeler

1 A wide variety of noises can come from the rear axle. Some are merely annoying, without denoting any defect that will result in mechanical failure. Others are warning of failure. 2 A noise can be traced to the rear axle as opposed to the gearbox by the fact that it is the same note or frequency whatever gear is engaged. It will tend to be loudest at 30 mph and 50 mph.

3 A noise that grows very gradually, over many thousands of miles, usually means that the axle will run for many more thousands of miles without failure. A noise that comes on quickly usually means a failure is imminent. 4 It is very difficult to make a definite diagnosis of what is

101

Chapter 8/Rear axle wrong from the noises. Also without great experience of that particular axie, it is very difficult to overhaul them and reassemble them so that they are noise free. 5 Gear whine when pulling will usually be either the differential case bearings, or the pinion to crown wheel backlash. 6 Gear noise when on over-run is likely to be the depth of mesh of the pinion and crown wheel teeth.

7

Thumping

is likely to be a chipped tooth, and should be

repaired immediately.

8

Noise on turns will be a gear failure of the differential side or

planet gears. The actual

differential will not whine, as its gears

turn so slowly. But if the teeth fail, then tearing or grunting noises can be heard on turns.

Fig. 8.4. General view of the rear axle in position

esent of bite owas”: oe

. Povay

awe,

iJ

S—

_

*

©

4a

o ®

ied Esmee

>

i

-

7 » 7

7

7

‘

=

od ~ ;

2=e =

‘isan

nae

a

5 dl

can a, weenOe *

. iy

a =

?

f «&

ony

of’

Chapter 9

Braking system

Contents

Specifications

Removing a front disc

General description Checking the front pads Changing the front pads Adjusting the rear brakes Adjusting the handbrake Inspecting the rear brakes

Changing the rear brake shoes Checking the servo action Bleeding the brakes Pedal free play and height Brake lights

...

Bes

oe

Pe

ds

12

1 2 3 4 5

Taking off a front caliper... aa Overhauling a front caliper ... an Removing a rear wheel cylinder _ ... Overhauling the master cylinder... Removing the master cylinder oe

ee

oes oe eae = ie

= eid es 538 ae

es eA sas at wes

13 14 15 16 iN7/

6

Overhauling the master cylinder...

aa

ss

ois

18

7 8 9 10 11

Reassembling the master cylinder ... Removing the servo power unit... Overhauling the power unit os Fault finding ... es a is

sai ve aes sss

ase ae was are

ae a x5 ae

19 20 21 22

Specifications Type

fe

Front disc rear drum, servo assisted

Master cylinder: Type Bore Maximum permissible clearance’ pore toPalston Pedal free travel. é Servo power unit: Type: Power cylinder: Diameter Stroke ...

Tandem 7/8 in (22.22 mm) 0.0059 in (0.15 mm)

Front brakes: pads per wheel pad lining

2 F50 46 mm wide x 14 mm thick x 97 mm

pad dimension Minimum front pad lining thickness Disc diameter oa Permissible disc run-out Front disc minimum thickness Rear brakes: Drum diameter Lining type Lining dimensions Rear wheel cylinder bore : Cylinder to piston clearance maximum Drum permissible out of round Permissible depth of machinery Brake fluid to

1

General description

1 The brakes are disc at the front and drum at the rear. The disc caliper is mounted in a slide, and is worked by one hydraulic piston on the inside. 2 The driver’s effort is assisted by a servo unit, getting its power from inlet manifold depression.

2

Checking the front brake pads

1

The thickness of lining left on the front brake pads should be

checked every 4,000 miles.

Ya - V2 in (5.15 mm) Bendix 6 in (152 mm)

1.38 in (35 mm)

long

5/16 in (8 mm) 9 in (230 mm) 0.0059 in (0.15 mm) 0.433 in (11 mm) 7.87 in (200 mm) D852 32x 4x 199mm % in (19.05 mm)

0.006 in (0.15 mm) 0.0059 in (0.15 mm) 0.039 in (1.0 mm) SAE J1703C or MV55:

116 DOT

3 or DOT 4

2Z To do this remove the front wheels. Looking down from above the caliper, the lining can be seen beside the disc. 3 The pads should be changed when the lining is down to 5/16 inch thick. When worn to that extent there is not enough material to last until the next check. The lining may not be worn evenly, and elsewhere, where it cannot be seen, the metal backing of the pad could be much nearer the disc. If the metal backing reaches the disc, braking will be reduced and the disc ruined, 4 It is rather difficult to see the pad behind the disc, but both must be checked, as they are likely to wear at slightly different rates due to their different exposure to dirt, and stiffness of the caliper on its slide.

104

Chapter 9/Brakes

ee

3

Changing the front brake pads

1 Jack up and remove the front wheel. 2 Pull out the spring clips locking the top and bottom caliper retainer wedges. See Fig. 9.1, and photo. 3 Draw the wedges out of the top and bottom of the caliper.

4 Tighten the cable till the wheels are locked when the lever is pulled up two or three notches. Of course no brake rub must be induced in the off position. Put the brake part-way on, and check that both wheels are the same stiffness to rotate. If not, an individual cable can be adjusted at the wheel end. (photo)

(photo) 4 Pull the caliper out rearwards. Note how the anti-rattle spring was fitted holding the two pads apart. Do not let the caliper hand on its flexible hose, but tie it up, or rest it on the front suspension where it cannot fall, and will not strain the hose.

6

5 Remove the shims and pads. Put the new pads in place. Note the far one has a little hole for the anti-rattle spring. 6 Before the caliper can be replaced, its hydraulic piston must be pushed back into the caliper cylinder. When this is done a lot of fluid will be returned to the master cylinder. 7 Check the level of fluid in the master cylinder. 8 Put a carpenter’s ‘G’ clamp over the cylinder, with a flat pad to prevent any damage to the piston. Press the piston back into the cylinder. If the master cylinder is so full that overflow, or splashing out on the move if too full, is likely, open the bleed nipple whilst the piston is moved, first putting on a bleed pipe, and immersing the end in a jar, in the fluid as it comes out, so no air can be drawn back in. 9 Refit the caliper. A trace of grease should be put on the wedges so that the caliper can slide to find centre. The anti-rattle spring must have its end in the little hole in the far pad, and be

that have threads in the drum, and use them as pullers. (photo) 4 Blow and rub all the dust and dirt off the linings, all the brake mechansim, and out of the drums. Check the amount of lining remaining, at its thinnest point: it wears unevenly as the shoe pivots. Check the dirt excluders on the hydraulic wheel cylinder to ensure there is no fluid leak. A very slight wetness inside the boot is permissible, but none must flow. Check there is no oi! or grease leak from the axle. Check the drum for cracks

Inspecting the rear brakes

1 The rear brakes should be inspected every 12,000 miles. 2 Jack up the car, and remove the rear wheels. 3 Remove the two bolts with long studs for positioning the rear wheels. Pull off the drums. If they do not come easily, screw

them off by putting the long headed bolts into the holes at 909)

or scores. 5

Replace the drum, and adjust the brakes.

7

Changing the rear brake shoes

tucked into the caliper. (photo) 10 Press the brake pedal to bring the pads up to the disc. 11 Repeat for the other side. Both sides must be done at the same time, or uneven braking may result. 12 Use the brakes gently for about twelve applications, to allow the pads to bed in. 4

Adjusting the rear brakes

1 On cars for some markets the rear brakes fitted do not have self-adjusters. The adjustment of these brakes is a 4,000 mile task. If the car is used with only modest braking, then it will be found that no adjustment is needed. The rear brakes have pull off springs, so on gentle braking, they provide relatively less brake effort than on hard stops. 2 The front brakes are inherently self-adjusting, as there are no pull-off springs, so the pads are merely thrown just out of contact by the disc. So if pedal travel becomes long, then this indicates adjustment of the rear brakes is needed. 3 Jack up the rear wheels. Remove the rubber grommets from the two little holes on both backing plates of the rear brakes.

(photo) Rub the dirt off the flat area just below the two adjuster holes, to clear the arrows marked there showing which way the adjuster must be moved. The first time this is done, it is recom-

mended the brake drum is removed to look at the adjuster, so you will know what you are trying to do. (photo) 4 Through the hole poke one adjuster round with a screwdriver, (photo) until the wheel can no longer be turned by hand. Then slacken it 5 notches. Then repeat for the other adjuster on that wheel, and the other wheel. 5 Road test the car. Stop up hill by the use of the gears, and check the rear brake drums are cool.

5

Adjusting the handbrake

1 The handbrake should not need routine adjustment, as the normal shoe adjusters do this. But after a time wear on the linkage, and stretch of the cable calls for resetting of the cables. This should be done if the movement of the lever is as much as 5 clicks, when the rear brakes are fully adjusted. 2 Adjust the rear brakes as described in the previous Section. 3 Tighten the single cable at the front end of the handbrake cable, joining the two cables to the lever. There is a nut and lock-nut on the end.

1 The risk of checked leading.

shoes must the metal again. The The shoes

be changed when the lining és so thin there is shoe reaching the drum before they will be trailing shoe wears at a slower rate than the should not be allowed to wear thinner than

1/16 inch (1.5 mm). This is the absolute safety minimum. Therefore they should be changed before that thinness is reached. As the

leading

shoes wear

faster than the rear, the rear may

not

need renewal. It is satisfactory to renew the leading ones only. It is important that whatever is done on one side of the car is repeated on the other, otherwise braking may be uneven. 2 Remove the drum as described in the previous Section.

3 Note the way the pull-off springs are fixed. Then unloop the bottom one from beneath the adjuster, and remove it. (photo) 4 Undo the steady springs, by turning the pin through

90° (photo) 5

Pull the bottom of the leading shoe forward, and then clear

of the adjuster. Then pull its top end out of the abutment on the piston. This will ease the load-on the top pull off spring, so this

can be disengaged. Now free the trailing shoe. 6 Disconnect the handbrake actuator from the trailing shoe, by unclipping the arm from the shoe: Leave the arm on the cable if possible, as it is rather difficult to get it back. 7 Whilst the shoes are off, clean and grease the adjuster. Puta trace of grease on the bottom of the shoes, and the springs.

8

Start to reassemble by fitting the trailing shoe to the hand-

brake arm, and to the shoe the top pull-off spring. Put the shoe

in place. (photo) 9 Hook the leading shoe onto the top spring, and get the top end of the shoe in place; then pull the shoe out, and get the bottom onto the adjuster. 10 Fit the bottom pull-off spring, and loop it under the adjuster.

11 Fit the steady springs. (Slightly greased). 12 Note that during the struggle to get the shoes into place the slight greasing on the bottom pivots of the shoes must not spread onto the linings, or the rubber dirt excluders at the top, from the hands. 13 Refit the drum. Adjust the brakes. 14 The brakes will need adjusting again quite soon, as the new linings will bed in to the shape of the drums. The first dozen or more brake applications after relining should be gentle, as the linings will not take the load over a wide area.

FIG. 9.1. THE FRONT BRAKE Stub axle nut

Inner bearing Nut keeper Dust seal Hub Disc NOOA®WMY™ Disc bolts

DISC AND CALIPER PARTS, AND THE HUB BEARING MOVE THE DISC 8

Grease seal

15 Caliper carrier

9 710 17 12 13 14

Grease cap Outer bearing Bearing washer Split pin Back plate Back plate bolts

16 Anti-rattle clip (2) 17 18 19 20 21 22

THAT MUST BE DISMANTLED

Calliper carrier dismantled Caliper assembly Piston Seal Dirt excluder boot Bleed nipple

23 24 25 26 27

TO RE -

Nipple cap Inner pad Shim Anti-rattle spring Pad wedges

28 Anti-rattle springs (2) 29 Wedge securing spring clips(2) 30 Outer pad

%

3.2 Pull out the spring clips

3.3 Then the wedges,

3.4 that hold the caliper to the carrier

3.4b This long anti-rattle spring has one end in the far pad, then tucks into the caliper

3.9 The two short anti-rattle springs, (white arrows) and one of the two

3.5a The anti-squawk shims go next to the pad

3.5b The inner and outer pads fit into the carrier

4.3a The rubber grommets sealing the adjuster holes

4.3b Seen from inside the drum, this is what the adjuster looks like

4.4 It must be poked round with a screw: driver through the hole

5.4 This cable adjuster at the back wheel is only used to even up the two cables

6.3 To pull off the drum

7.3 Note the lower pull-off spring (white arrow) and the two steady springs

7.4a The steady springs are released by turning the pins 90°

7.Ab The flat head of the pin Sh then go through the slot in the spring clip

anti-rattle clips (black arrow)

(black arrows)

107

7.5 Pull the shoes out of their place on the pistons to ease the load off the spring

Fig. 9.2. The handbrake lever and cable parts

7.8 On reassembly they can be more easily hooked on there too

108

8

Chapter 9/Brakes

10 Pedal free play and height

Checking the brake servo action

1 Poor braking can come on gradually, so escape notice. If the pedal pressure seems high the servo action should be checked as follows. 2 Doa brake test from about 25 mph, on a smooth, level, and traffic free road. The car should pull up straight, and it should be possible to lock the wheels, leaving black tyre marks. 3 Switch off the engine. Apply the brakes about six times to deplete the vacuum reserve.

4 Press the pedal down, and hold the brakes on lightly. Start the engine; the pedal will tend to fall away from the foot: less pressure will be needed to hold the brakes applied. If this effect

is not felt the servo is not giving assistance. 5

Start

up.

Run

the engine

at medium

speed, to

build

up

depression. Switch off the engine and close the throttle. Wait for 90 seconds. Then try the brakes. There should be enough

1 There must be some free play between the pedal push rod and the master cylinder and servo pistons, so that the master cylinder piston can return to the end of the cylinder. Unless it can do this the hydraulic fluid in the pipes cannot escape back to the reservoir, so when it heats and expands, the brakes will bind. Also the reservoir could not feed the system. 2 The free play is adjusted by undoing the lock nut on the pushrod, and then screwing the rod on the yoke at the pedal. The free play should be % - % inch. 3 The position of the pedal in the released position can also be

adjusted. dashboard switch is play must

This is done by moving the stop lamp switch on the above the pedal. It should only need altering if the failing to make fair contact. After altering it, the free be readjusted.

vacuum for two or three applications of the brakes. If the depression has been lost either the check valve is faulty, or there is a leak.

11 Brake lights

9

pedal return stop. 2 The lights should be checked frequently by reversing close up to a wall.

1 Bleeding the brakes

1 If the hydraulic system has air in it, operation will be spongy and imprecise. Air will get in whenever the system is dismantled, or if it runs low. The latter is likely to happen as the brakes wear, and the pistons move further out in the wheel cylinders.

Air can leak into the system, sometimes through a fault too slight to let fluid out. In this latter case it indicates a general overhaul of the system is needed. Bleeding is also used at the 30,000 miles task, to change the brake fluid. 2

You will need:

a) b) c) d) e)

An assistant to pump the pedal A good supply of new hydraulic fluid An empty glass jar A plastic or rubber pipe to fit the bleed nipple A spanner for the nipple

3 Top up the master cylinder, and put fluid in the bleed jar to a depth of about % inch. 4 Start at the nipple furthest away from the master cylinder; ie rear brake, passenger side, and work nearer.

5 6

Clean the nipple and put the pipe on it. Tell your assistant to give a few quick strokes to pump up

pressure, and then hold the pedal on. 7 Slacken the nipple, about % or 1 turn, till the fluid or air begins to come out. This is usually quite apparent either as bubbles or dirt in the clean fluid in the jar.

8

The brake lights are worked by a switch combined with the

12 Removing a front brake disc

1 Remove the brake callper by pulling out the spring clips and wedges as described in Section 3. Put the caliper up on the suspension where the flexible pipe cannot get damaged. 2 Undo the two bolts securing the caliper mounting to the brake back plate, and take it off. See Fig. 9.1. 3 Prise off the grease cap from the hub. Pull out the split pin, and undo the hub nut on the stub axle. Take off the hub with disc. For details of the bearings, and their readjustment

afterwards, see Chapter 11/3. 4 If the disc is to be refitted, mark its position. Then mount the disc in a soft jawed vice. Undo the bolts securing it to the

hub. 5 When assembling the disc to the hub, make sure the mating surface is clean. 6

Refit the hub to the stub axle. Tighten the bearing nut, but

do not yet fit the split pin. 7 Check the run-out of the disc, with a dial gauge near its rim. If it exceeds the specification, take the disc off, put it on in another position, and try again.

8

Finaily adjust the bearings as given in Chapter 11/3. Refit the

caliper.

As soon as the flow starts, tell the assistant to keep pumping

the pedal everytime it gets to the end of its travel, and tell you all the time where the pedal is; ‘down, up’ etc. 9 As soon as air has stopped coming out shut the bleed nipple; do so as the assistant is pushing the pedal down. Do not go on too long, lest the reservoir be emptied, and more air pumped in. About 15 pedal pumps is safe. 10 Refill the reservoir, and repeat at the other wheels. Also keep going on the original wheel after refilling the reservoir if dirty fluid is still coming out, to get rid of all the old. 11 Bleeding is greatly speeded, and can be done by one person, if spring loaded valves are fitted to the nipples. These are available from accessory shops. 12 Keep hydraulic fluid clear of the car’s paint. It ruins it. Throw old fluid away. It attracts damp, so deteriorates in use. 13 If there is difficulty in getting air out of the system, then each time the assistant releases the pedal, close the nipple, so no back flow can take place.

14 On cars with pressure differential

switches to give warning

when pressure falls in one of the brake lines, the valve may stay over to one side after bleeding. If this occurs, bleed a very small amount out of the other, to allow the valve to centralise.

13 Taking off a front brake caliper 1

As described in Section 3 or 12, the caliper is often put aside

to get at the brake pads or hub bearing. If it needs overhaul then it must be properly taken off. 2 Jack up, remove the wheel. 3 Wash the area around the caliper, and the union to it for flexible brake pipe, using detergent and plenty of water. 4 If fitting a reconditioned caliper complete, now undo flexible brake pipe. Put a jar to catch the brake fluid. Take the split pins, and pull out the wedges. Then lift the caliper

the the out off.

5 If overhauling the caliper, part of the stripping must be done still on the car. Remove the spring clips and wedges, and take the caliper off its mounting. Clean around the piston. Put a large tin under the caliper. Take off the rubber boot dirt excluder. Get an assistant to gently press the brake pedal. This will blow the piston out of the cylinder. Put a piece of wood to catch it. Put down the piston where it will not get damaged. Temporarily put the caliper back on its mounting to hold it formly; then undo the pipe union. Now it can be taken off, and to a bench for overhaul.

109

Fig. 9.3. The hydraulic piping of the brake and clutch systems

9.14 The valve may need centralising after bleeding

FIG. 9.4. THE BRAKE PEDAL AND ITS CONNECTION TO THE MASTER CYLINDER THROUGH THE SERVO

(2)}——

Master cylinder

Servo Push rod Return spring Stop lamp switch Stop locknut Pushrod locknut Pedal ANAAAWY™

(3)

110

Chapter 9/Brakes

14 Overhauling the front brake caliper

16 Overhauling the wheel cylinder

1 Before starting, get a set of the piston seals, and dirt excluders. Never attempt to reuse the old ones. 2 Remove the caliper, and the piston from the caliper, as described in the previous Section.

never be reused. 2 There is no need to remove

3 Prise the seal out of the cylinder. Then clean all the parts using alcohol or brake fluid. Blow with an air line. Do not use petrol or paraffin (gasolene or kerosene) as traces of this will remain, and will ruin the seals.

4 Examine all parts for scores or pitting. Minor ones can be cleaned up with metal polish. Any too bad for this means replacement parts must be fitted. 5 Wet all the parts with brake fluid. 6 Fit the new seal to the cylinder. Put the piston in the cylinder. Install the rubber boot. 7 Refit the caliper to the car. 8 Note that if one caliper needs overhaul, the other is probably nearly in the same condition too. If there is any likelihood that

the wrong fluid has been used, then all must be drained out, the whole system flushed out with alcohol, then the master cylinder cups, and flexible pipes, and all wheel cylinder rubbers renewed. 9 Fill the reservoir with new brake fluid. Bleed the brakes. 10 Check for leaks.

1

Get replacement rubbers before starting. The old ones should

the wheel cylinder from the car. Indeed, there is less chance of introducing dirt if the pipe at the rear need not be undone. It only need be removed to fit a replacement. Remove the drum and brake shoes. 3 Remove the rubber boots from both ends of the cylinder. 4 Push the piston at one end of the cylinder right in, so the other is ejected from the far end. Note the order of piston, cup, spring seat and spring. Get out the piston at the other end. See

Fig. 9.5. 5

Wash

all the parts in alcohol

parts for scoring: or piston and cylinder. 0.006 inch (0.15 mm) 6 Wet all the parts

or brake fluid. Check

all the

pitting. Check the clearance between the If damaged, or the clearance is more than a new assembly should be fitted. with brake fluid, then reassemble. Fit the

brake shoes, and temporarily the drum. 7 Bleed the brakes.

8

Remove the drum and check for leaks.

9

Refit the drum and adjust the brakes.

17 Removing the master cylinder - without servo 15 Removing a rear wheel cylinder 1 Remove the drum Sections 6 and 7.

and

rear

brake

shoe

as

described

in

1 Get a can ready to catch the fluid, and cover the car paintwork with newspaper, as fluid will ruin it. Undo the pipes from the reservoir on the bulkhead. 2 Undo the pipes from the cylinder to the front and rear

2 Wash all around the wheel cylinder, especially the rear or inner side of the back plate, around the union for the pipe, and the fixing nuts, using detergent and plenty of water. 3 Undo the union, and put a can to catch any drips of fluid. Do

brakes. (photo) 3 Undo the nuts holding the master cylinder to the servo power unit. 4 Pull the master cylinder straight forward, off the servo.

not try to stop it draining out. If the wheel cylinder has been giving trouble, then the brake fluid is unlikely to be worth

pedal. See Section 10. Bleed the brakes; see Section 9.

saving. (photo) 4 Undo the nuts holding the wheel cylinder to the back plate, and take it off.

5

After replacing the master cylinder, check the free play at the

6 Note that on early cars the reservoir is on top of the master cylinder, so there is no need to drain it first.

18 Overhauling the master cylinder 1

A

complete

set

of rubbers

will be needed.

The

working

conditions must be very clean. 2 Remove the master cylinder, either alone as described in the previous Section, or with the servo unit, as described in Section

FIG. 9.5. REAR WHEEL

OPERATING

CYLINDER

1 2 3

Sealing ball valve Bleed nipple Nipple cap

5 6 7

Piston cup Piston Dust boot

4

Seat

8

Cup spring seats

20. 3 Tip away the old fluid. 4 Clean the outside of the master cylinder. 5 Remove the dust boot. If the early type with reservoir on the cylinder, remove it. See Fig. 9.6. 6 Take out the circlip and remove the stop washer. 7

Remove

the primary

piston, spacer, piston cups, spring seat

and return spring from the cylinder. See Fig. 9.7. 8 Loosen the secondary piston with a screwdriver, the stop bolt hole a guide secondary cup. See Fig.

piston stop bolt. Push in the secondary and remove the stop bolt. Insert into pin made up specially to compress the 9.8. Ease the pressure on the screw-

driver,

secondary

and

remove

the

piston,

spacer,

piston

cyp,

secondary cup, spring seat, and return spring. If necessary, blow them out of the cylinder. 9 Remove the fluid pipe fittings from the cylinder, and the check valves and springs.

10 Lay out all the parts so that they will not get muddled up. 11 Clean all the parts in alcohol or brake fluid. Petro! or paraffin must not be used, as traces of this will remain, and ruin the new rubbers. 12 Examine all parts for damage, scoring, or pitting. Check the clearance between cylinder and pistons does not exceed 0.096

inch (0.15 mm). Replace parts as necessary. 13 Ensure that the ports leading from the reservoir unions to the 15.3 The rear wheel cylinder from behind

cylinder are clear.

17.2 The pipes are undone from the

17.3 Access is easier on left hand drive

unions, and the unions left on the master cylinder

FIG. 9.6. BRAKE MASTER Reservoir cap Baffle Reservoir Bush

cars

CYLINDER.

17.5 Never reuse old fluid. Always use fluid that meets the specification

LATER ONES HAVE PIPES FROM THE BULKHEAD INSTEAD OF IT BEING ON TOP

Stopper valve Secondary cup Washer Circlip

9 10 17 12

Valve rod Spring Spring seat Primary cup

MOUNTED 13 14 715 16

RESERVOIR,

Secondary cup Secondary piston Primary cup Primary piston

112

Chapter 9/Brakes

Fig. 9.7. The master cylinder. In this case the later type with unions for pipes from the bulkhead mounted reservoir

With guide pin

Secondary

cup

Secondary piston

Cylinder Fig. 9.8. To ease the secondary cup of the secondary piston out, and the primary cup in, a guide pin must be made to fit in the hole for the stop bolt. It needs to

be made from a 5 mm or 3/16 inch bolt, cut

to an

effective

length

Guide pin Without guide pin

of 8.5 mm,

which is nearly 3/8 inch.

lel

= Chamfer

14 If the master cylinder has needed overhaul, then it is likely

the wheel cylinders will do so too. If the incorrect type of fluid has been put in, the whole system must be flushed out with alcohol. New rubbers must flexible pipes renewed.

be fitted to all cylinders, and the

10 Fit the rubber boot. 11 Fit the master cylinder to the servo unit. Connect up the brake pipes, and the reservoir. Fill the reservoir. Bleed the system. Check the free play at the pedal. Check for leaks. Road test the car, and test the brakes.

19 Reassembling the master cylinder

20 Removing the brake servo power unit

1

Wet all the parts in brake fluid.

2 3

Fit the check valves and springs with the outlet fittings. Fit the large diameter return spring with its seat.

1 If the checks in Section 8 show the power unit to be faulty, it is quite easy to remove it, but its overhaul is delicate. It is recommended that if possible a reconditioned unit is fitted. If it

4 Fit the primary and secondary cups to the secondary piston, back to back, lips outwards.

5 Put the guide pin in the stop bolt hole, and insert the secondary piston assembly, with spring seat, into the cylinder. 6 Push the secondary piston up the cylinder with a screwdriver, as far as it will go. Remove the guide pin and insert the stop bolt. 7 Fit the primary and secondary cups to the primary piston, both with lips towards the secondary piston. 8 Fit the smaller return spring, and then the primary piston with spring seat. 9 Fit the stop washer and circlip. Check the pistons return to the off position, uncovering the ports.

has to be overhauled, then a set of new washers, seals and gaskets

will be essential. 2 The master cylinder is removed with the servo, then the two separated. 3 Have a container ready; then remove the pipes to the master cylinder from the reservoir. Do not let any fluid drip on the car, as it will ruin the paint. 4 Undo the pipes from the master cylinder to the front and rear brakes. 5 Disconnect the suction pipe from the manifold at the servo. 6 Disconnect the push rod at the brake pedal by removing the split pin and taking out the clevis pin.

113

Chapter 9/Brakes Eee

7 8

Undo the nuts that hold the servo unit to the dash. Lift off the assembly of master cylinder and servo. Take care the hydraulic fluid does not drip on the paint. 9 Clean the outside with alcohol or brake fluid. 10 Undo the nuts securing the master cylinder to the servo, and separate the two.

21 Overhauling the brake servo power unit 1 Remove the check valve for the suction on the servo front shell. 2 Mount the servo in a vice, pedal push rod end up, using padded jaws on the mounting flange for the master cylinder. 3 Scribe a mark so that the front and rear parts of the shell of the vacuum cylinder will be reassembled in the same orientation. 4 Remove the boot. 5 Arrange a pair of long levers on the servo’s studs that secured it to the dash. Rotate the rear shell clockwise to disengage its lips from those on the front shell. Hold it down whilst turning, to hold the rear shell down against the power piston’s return spring.

6

Lift the components out of the front shell.

7 8

Remove the rear shell from the valve body. Remove the diaphragm from the plate/valve body.

9 Remove the air silencer with the air filter from the valve body, being careful not to chip the plastics. 10 Press in the valve rod, and remove the valve retainer key. Remove the valve rod and plunger assembly. 11 Note that the valve rod and plunger are serviced as an assembly only. 12 Press the reaction disc out of the valve body. 13 Remove the push rod. 14 Remove the front seal from the front shell if it needs

replacement; replacement is recommended. The same applies to the rear seal. 15 Examine all parts for distortion, cracks, scratches etc. It is recommended that unless some particular defect has occurred after a short mileage, all flexible parts, such as the diaphragm, seals etc, are all replaced, as having been disturbed they are unlikely to be reliable for long. 16 Apply the special power brake lubricant to the cylinder surface of the plate/valve body and to the surfaces of the valve rod and plunger. 17 Insert the valve rod and plunger assembly into the valve body.

18 Press down on the valve rod and align the groove in the valve plunger with the slot in the valve body, and insert the retainer key. 19 Fit the diaphragm over the plate part of the valve body making certain the diaphragm is seated in the groove. 20 Put the air filter and silencer over the rod and into the valve body. 21 Lubricate the entire surface of the reaction disc liberally with power brake lubricant, and put it in the valve body. 22 Lubricate with power brake lubricant the outer bead of the diaphragm, and the part that touches the shell, to help assembly. 23 Fit the new seal to the rear shell. Lubricate it with the power brake lubricant, and then fit it carefully to the valve body. 24 Fit the new seal to the front shell. 25 Put in the return spring, and then reassemble the components into the front shell. 26 Close the two halves of the shell of the vacuum cylinder by rotating them anti-clockwise to engage the lips. 27 Fit the boot. Put the master cylinder back on. 28 Refit» the assembly to the car. Bleed the brakes. Adjust action, as detailed in Section 8.

ORCROROROR®

FIG. 9.9. THE BRAKE SERVO POWER UNIT

Rea ys

TANS

Check valve Push rod Diaphragm

Power piston/plate/valve body Reaction disc Vacuum passage Air valve plunger

Spring CONDAGH AWN Spring

70 Silencer 17 Filter 12 Front shell of the vacuum cylinder

713 Return spring 14 Key

75 Rear shell 716 Atmosphere port

17 Air valve piston

18 Floating control valve 719 Boot 20 Valve rod and plunger

22 Fault finding

Before diagnosing faults in the brake system check that any irregularities are not caused by:

1 2

3 4 5

Uneven and incorrect tyre pressures Incorrect ‘mix’ of radial and cross-ply tyres Wear in the steering mechanism Defects in the suspension and shock absorbers Misalignment of the bodyframe

Symptom

Reason/s

Pedal travels a long way before the brakes operate

Brake shoes set too far from the drums

Remedy :

Adjust the brake shoes to the drums.

(This applies equally even though disc brakes are

fitted,

but

only

the

rear

drums

need

adjustment.) Stopping ability poor, even though pedal pressure is firm

Linings and/or drums badly worn or scored One or more wheel hydraulic cylinders seized, resulting in some brake shoes not pressing against the drums (or pads against

discs) Brake linings contaminated with oil

Car veers to one side when the brakes are applied

Dismantle, inspect and renew as required.

Dismantle and inspect wheel cylinders. Renew as necessary. Renew linings and repair source of oil contamination.

Wrong type of linings fitted

Verify type of material the car and fit it.

which

is correct for

Brake shoes wrongly assembled Servo power unit inoperative

Check for correct assembly. Check manifold vacuum pipe overhaul servo.

Brake linings on one side are contaminated

with oil/grease/hydraulic fluid Hydraulic wheel cylinder on one side partially or fully seized A mixture of lining materials fitted between sides Unequal wear between sides caused by partially seized wheel cylinders

Renew linings and stop leak. Inspect wheel cylinders for correct operation and renew as necessary. Standardise on types of linings fitted.

Check wheel! cylinders and renew linings and drums as required.

Pedal feels spongy when the brakes are applied

Air is present in the hydraulic system

Bleed the hydraulic system any signs of leakage.

Pedal feels springy when the brakes are applied

Brake tinings not bedded into the drums

Allow time for new linings to bed in after which it will certainly be necessary to adjust

(after fitting new ones)

and check for

the shoes to the drums as pedal travel will have increased.

Master cylinder or brake backplate mounting bolts loose

Brakes overheating

Pedal travels right down with little or no resistance and brakes are virtually non-operative

Pedal creeps down when held on

Brake juddering

Retighten mounting bolts.

Brakes used too severely

Drive less hard.

Brakes binding

Check rear drum adjuster. Check master cylinder free play:

Leak in hydraulic system resulting in lack of pressure for operating wheel cylinders

Examine

the whole

of the hydraulic system

and locate and repair source of leaks. Test after repairing each and every leak source.

If no signs of leakage are apparent the master cylinder internal seals are failing to sustain pressure

Overhaul master cylinder. If indications are that seals have failed for reasons other than wear all the wheel cylinder seals should be checked also and the system completely replenished with the correct fluid.

Hydraulic leak

If no visible leak, master cylinder cups are being by-passed and need renewal.

Disc/drum out of true

Measure and replace. Tighten. Clean out drums.

Back plate loose Lining dust or road dirt inside rear drums

Chapter 10 Electrical system Contents

Specifications General description The battery- general Hesenoton Electrolyte Charging ... Battery leaks anive corrosion Alternator description

Testing the alternator Removal of the alternator Stripping and examining the alternator The regulator Starter motor - general erreneencnt Starter motor - maintenance

Removal of the starter motor Dismantling the starter Checking the starter Starter motor failures Reassembling the starter Windscreen wiper motor Lamps ae Turn indicator focher Instruments Horn OMDNOoORWN— Fuses ... Fault finding Pern Fault diagnosis

Specifications Battery...

Starter motor Capacity Free running test Lock test

Brush spring tension oe Magnet switch operating voltage Alternator Polarity Rated output Number of poles No load test ... Load test

Brush spring pressure Slip ring diameter Ratio of alternator to ein speed Regulator Constant voltage relay

Regulated voltage, without load Bulbs Headlamp 6 Front turn signal & ue oe Side turn signal lamp Fog lamp Interior lamp Step lamp Glove compartment lamp

Turn signal lamp (rear) Stop, tail & reverse lamp Licence lamp

60 amp hour

1.0 Kw Voltage: Current: Voltage: Current:

12V Less than 70A at 3600 rpm or more 6.0 V 60A or less

Torque: 2.7 m kg (19.5 lb ft) 1.13 kg (40.0 oz) 9.0 V

Negative earth

12V40A 8 Voltage: Current: Voltage: Current:

14V at 1050 rpm or less OA 14V at 2500 rpm or less 32A

350 gr (12.5 oz)

33 mm + 0.2 (1.299 + 0.008 in) 2:1

Air gap: 0.7 - 1.1 mm (0.028 - 0.043 in) Point gap: 0.3 - 0.4 mm (0.012 - 0.016 in) Back gap: 0.7 - 1.1 mm (0.028 - 0.043 in)

14+ 0.5V

50W/40w 21W/5W 3.4W 25W SW 6W 5W 21W 21W/5W/10W 10W

13 14 15 16 Ur/ 18 19

8

21 22 23 24 25

116

1

Chapter 10/Electrical system

5

General description

1 The electrical system is 12 volt, negative earth. The charging is done by an alternator. The starter motor is the pre-engaged type.

2 The emissions control system has electric sensing and operation of the control valves. This is dealt with in Chapter 3. 3 Much of the electric equipment is fitted to the dash, for which access to its rear is required. This is dealt with in Chapter 123

Battery leaks and corrosion

1 If the battery leaks, remove it immediately before the acid can do any more damage. 2 If the casing is cracked, take it to an expert to mend. It is not at all easy to get a repair to last. The corrosion from a leak is so severe that it is not a good risk to have an unreliable repair. Leaks in the joint round the top are more easily dealt with. A small one can be filled with a household sealant, but for larger cracks melt some pitch. 3 Halt any corrosion in the car by washing out the front with

plenty of water. 2

The battery - general maintenance

1 A large battery of 60 ampere hours capacity is fitted. This is because Wankel engines can call for much cranking to start. Initially there is a lot of friction from the seals. Then the engine may not fire for some time as compression is poor until running, as there is no gas pressure behind the apex seals. 2 Topping up the electrolyte is a weekly task, though it may need doing daily when on long journies. 3 When inspecting the engine compartment the battery should be checked for leaks, security, and corrosion. The terminals should not corrode if properly protected. To do so, disconnect them, and take out the terminal bolt. Clean all very thoroughly.

Smear

liberally

with

vaseline

(petroleum

jelly), not

grease.

Reassemble, and wipe off the surplus vaseline. If the area near the battery corrodes, treat it as described in Section 5,

3

Electrolyte

1 The liquid in the battery is sulphuric corrosive to the car, you, and your clothes.

2

acid.

It is highly

It should be kept topped up with pure water. The acid itself

does not get used up. The water bubbles off as gas as the battery

4 Once thoroughly dry, paint with a zinc based rust preventer, followed by the normal undercoat and top coats of paint.

6

Alternator description

1 The alternator develops its current in the stationary windings, the rotor carrying the field. The brushes therefore carry only a small current, so they last a long time, and only simple slip rings are needed instead of a commutator. 2 The AC voltage is rectified by a bank of diodes. These also prevent battery discharge through the alternator. 3 Very little servicing is needed. About every 50,000 the alternator should be stripped and the brushes cleaned and checked.

4

Fault-finding is more a matter of confirming the fault is in

the alternator, and it is probable then that a new unit will have to be fitted. However, if parts are available, component repair is possible. To fit new rectifiers or stator windings requires experience with a soldering iron, and should not be done by someone completely inexperienced. 5 The adjustment of the alternator drive belt is a 4,000 mile

(6,000 km) task, and was detailed in task 2.3 of the Routine Maintenance.

charges. The water is normally got in the form of distilled water. It is better to top it up with drinking water than to let the level get low for lack of the distilled water. 3 Due to chemical reactions inside, the electrolyte specific

6 To prevent damage to the rectifying diodes, the alternator leads should be disconnected whenever electric welding is being done on the car.

gravity

7

(sp gr) falls as the

battery

discharges.

This

can

be

Testing the alternator

measured with a hydrometer. 4 lf the battery acid is spilled the lost electrolyte must be replaced with acid. This must be mixed to the correct sp gr. If diluted concentrated acid, pour the acid into the water. NEVER add water to acid: It will explode. First dilute with 1 part acid to 2% parts water. Then continue till the required sp gr. is achieved as appropriate for that temperature.

1 The alternator can be initially tested on the car, as it will need to be run up to speed by the engine. 2 Disconnect the ‘B’ termina! which is the threaded post one, and insert between the wire and the terminal a 0-50 amp ammeter, the positive lead being on the alternator. Connect a voltmeter accurate to 0.25 volts, from the ‘B’ terminal to earth.

5

3 Start up the engine, turn on the headlights to load the alternator, and run the engine at 2,000 rpm. 4 The voltage should be 13.5 - 14.5 and the current 32 amps. 5 If the current is low the alternator is faulty. If the voltage is low the regulator is at fault.

On old batteries the sp gr. cannot be got back to that of a

new one due to permanent chemical changes.

4

Charging

1 If the car is used frequently, on good journies, and has a young battery, the alternator will keep the battery fully charged. 2 Old batteries do not hold their charge. 3 Town journies do not give good charges due to idling at

traffic halts. 4 If the battery is not kept fully charged its plates deteriorate faster than normal. 5 In winter the battery may well not be kept properly charged. It should therefore be recharged from an outside source at least once in the winter. 6 Charge at a rate not exceeding 3% amps. When fully charged the battery gasses move freely, and the sp gr. reaches a maximum. Continue to charge for about 2 hours after this. 7 Do not have a so called ‘‘boost charge”, which takes only about 1-2 hours. This will shorten the life of the battery by a factor of many years. 8 An old battery can often be revived by “’cycling’”’ it once or twice. Let it discharge fully, slowly, by leaving the parking lamps on. Then charge it at only 1%-2 amps, till fully charged.

8

Removal of the alternator

1 2

Disconnect the battery. Disconnect the wires to the alternator, at the plug and the

terminal post. (photo) 3

Remove

the bolt in the adjustment

slot. Slacken

pivot bolt. Remove the drive belt. 4 Take out the pivot bolt, and lift out the alternator.

9

the long (photo)

Stripping and examining the alternator

1 It is assumed at this stage that the alternator is only being stripped either to clean and check the brushes, or to trace a fault. So only partial dismantling is necessary. Fault-finding and repair should be left to the official agent if you have no experience of electricity and electronics.

2

Undo

the

long bolts clamping

the two

parts of the body

8.2 The connections to the alternator are made at this plug, and a threaded

8.3 The mountings and adjustment slot of the alternator

8.4 The long pivot bolt for mounting the alternator

terminal post for the main output

Brush holder Stator

FIG. 10.1. THE ALTERNATOR

Ball bearing (rear) Seal Brush end of body Heat sink Heat sink Clamp OANDAAARWH™~ Insulator 70 Rotor 17 Bearing plate

12 Ball bearing (front) 13 14 15 76

Drive-end of body Pulley ass’y Spring washer Nut

118

Chapter 10/Electrical system

together. Prise them apart, keeping the two straight. Pull the front part away, with the rotor still inside.

4 If the regulator is set at too low a limiting voltage, the battery will be kept just off full charge, so will deteriorate. If set

3

too high, on long journies the battery will be overcharged. In the short term this calis for frequent topping up of the battery. In the long term it is not good for the battery. 5 As the alternator output rises the increased magnetic field in the regulator windings draws the armature down against its blade spring, so Opening the contacts. This cuts the field current. The armature then vibrates as required to control the output. The setting depends on the mechanical adjustment of the points, and

Clean all the parts, but do not dip them in any liquid. Check

the condition

of the slip rings, which

should be smooth

and

shiny. The brushes’ minimum length of 2/3 of their original. 4 If the alternator has failed, it is now check the field windings on the rotor, and As a repair will need knowledge of radio soldering without overheating the diodes; assumed

here. Check

the windings

stripped enough to the stator windings. techniques, such as some knowledge is

are neither

open

circuit, or

shorted to their rotor/stator. The resistance of the field windings on the rotor whould 5 - 6 ohms. Check the diodes only allow current in one direction. 5 If the diodes or stator coils need replacement they must be unsoldered and removed from the brush-end of the body. Note all leads so that they can be reconnected correctly.

6 If the rotor or the bearings need replacement the drive-end must be dismantled. Undo the nut on the end of the shaft holding on the pulley. Pad the rotor, and put it in a vice with soft jaws, and then undo the nut. Press the drive-end bracket with the bearing off the shaft. The brush-end bearing can be pulled off the other end of the shaft. 7 The bearings are lubricated and then sealed on assembly. If they feel dry or rough, they should be replaced. 8 When reassembling, the brushes have to be fitted into their holders, and tied up with wire that can be withdrawn through the slots in the brush-end of the body.

the strength of the spring. Once the mechanical adjustments have been set, output is adjusted by tensioning the spring by bending its abutment stop. The adjustment of this stop is very delicate, a small bend giving a big effect.

6 After a long time the contacts will need cleaning. They should be polished with fine emery cloth. Then all dust must be cleaned away. Reset the mechanical clearances; point gap; air gap between

core and armature; back gap between the frame and the

contact arm. 7 For the electric setting the battery must be fully charged, so that little load is drawn. An old battery can never be fully recharged, so it may be necessary to buy or borrow a new One. Give it a final charge from a battery charger.

8 Connect a voltmeter between the ‘A’ and ‘E’ terminals of the regulator, Start the engine. Run it for about ten minutes at 2,000 rpm to stabilise the temperature of the regulator, and to recharge the battery after starting up. 9 With the engine still at 2,000 rpm, read the voltage. Allow the engine to slow down, and speed it up again, and watch for a

kick on the voltmeter as regulation starts. The reading should be 10 Regulator 1 A seprrate regulator is used to control alternator output, it being a single armature controlling current and voltage. 2 The regulator controls the current to the field coils, and responds to battery condition and the electrical load being drawn. 3 The correct function of the regulator is shown by the ammeter. Whenever the battery is less than fully charged, the charging rate is relatively high, and extremely so, immediately after starting up. As the battery becomes fully charged, the charge rate cuts back to a trickle. If an electric load is drawn, such as turning on the headlamps, the regulator responds and keeps the battery charge much as it was before. This effect should be noted when all is well, so that when trouble is suspected the ammeter readings can be interpreted readily.

Back

13.5 - 14.5 volts. 10 If the car is used much for stop-start driving, the output wants to be up the top end of the tolerance. If the work is mainly long journies, particularly in a hot climate, then it should be at the bottom end. To lower the voltage, the regulator spring must be weakened; the stop must be bent down, but only by a small amount.

Bending it up raises the output.

11 Starter motor - general arrangement 1 The starter is of the pre-engaged type. Turning the ignition key through to the start position connects battery voltage to the solenoid. It also works the relay for the boost arrangements on

the leading ignition coil, cutting out the ballast resistance, as when the starter is turning it will take most of the battery voltage.

8ap-

f—

Point

Zap

Fig. 10.2a. The regulator mechanical settings

Fig. 10.2b. Adjusting the regulator

119

Chapter 10/Electrical system 2

The starter solenoid draws the starter drive gear into engage-

ment with the flywheel. Once this is complete, the starter motor itself is connected. 3 Once the engine is running, and before the driver has had a chance to release the starter, the starter would be carried up to high speed by the engine. So a free-wheel is put in the drive to

allow the engine to over-run the starter.

12 Starter motor - maintenance

No routine maintenance is called for on the starter. It will work without attention for about the same mileage as the engine will go without overhaul. It should therefore be overhauled at the same time. All that should be needed is cleaning, replacement of the brushes, and re-lubrication.

11.1 On the end of the starter motor is the engagement gear, and reduction drive

13 Removal of the starter motor

1 2

Disconnect a battery terminal. Disconnect from the starter solenoid the small wire and the

heavy cable. (photos) 3 Undo the two nuts and two bolts holding the starter to the top of the engine, and lift it off.

14 Dismantling the starter 1 Disconnect the lead into the starter, to the field windings, from the terminal on the solenoid.

2 Take out the screws holding the solenoid to the housing. Remove the solenoid, with its spring and washers, and unhook the plunger from the gear lever. 3 Take out the through bolts, and remove the rear bracket. Take the insulator and washer from the end of the armature. 4 Take the yoke off the centre bracket. 5 Take the armature out of the centre bracket, with its thrust washer at the geared end of the shaft. 6 Separate the centre and front brackets. 7 Remove the gear lever, spring, and spring seat. Take out the freewheel from the front bracket.

13.2a The thin wire to the solenoid is the control from the ignition starter switch

15 Checking the starter

1 In cleaning the parts do not immerse the free-wheel in cleaning liquid, as it is ‘’sealed’’, so liquid will get in, but not out, and new grease cannot be put in.

2

Check all parts for damage.

3 The armature should be bright. If rough or burned it should be refaced. Minor marks can be removed by emery cloth, but if bad it will need a very light skim taken off on a lathe. The insulating material between the copper segments should be undercut. If not badly worn, the undercuts will need scraping out with a narrow screwdriver. If the commutator is refaced, then the undercutting must be redone, with a broken hacksaw blade, to a depth of about 1/32 inch (0.8 mm). The hacksaw blade should be narrowed on a grindstone so that it just fits between the copper segments. The commutator is not very strong, so all this work must be done lightly. Afterwards all grit must be cleaned off thoroughly. 4 The brushes should be replaced if they are worn more than 1/3 of their length. The new ones have to be soldered in place. Cut the old ones off leaving a good length of copper to which to solder the new ones. 5 If the clearance between the armature shaft and bushes exceeds 0.08 inches (0.2 mm) the bushes must be replaced. Soak the new ones in engine oil for 24 hours before pressing them in. If the old ones are kept, reoil them, and allow some time for oil to work into their pores.

13.2b The heavy cable is the live lead for the starter. The cable to the starter field is below and in series with, the

armature ee

13.3 Remove the air cleaner, then accessibility is good

120

Chapter 10/Electrical system

FIG. 10.3. THE STARTER MOTOR 1 Front bracket 2 Plunger 3 Spring 4 Gearlever 5 Solenoid 6 Gear lever spring 7 Free wheel 8 Metal 9 Washer 10Washer 11 Metal 12 Centre bracket 13 Washer 14 Armature 15 Insulator 16 Washer 17 Pinionshaft 18 Washer 19 Washer 20 Bush 21 Yoke 22 Field coil 23 Brush 24 Brush spring 25 Metal bush 26 Rear bracket 27 Through bolt

16 Starter motor failures

1 The solenoid can be checked for correct function. It must be tested for ’pull-in’ and ‘hold-in’. 2 Apply 12 volts between the switch terminal and that for the field winding of the starter. This is best done with the solenoid fitted to the assembled starter, so it has to move the gear. The field wire should be off its terminal. The solenoid should engage the gear without hesitation. 3 Now join the field terminal to the solenoid body, and the body to the negative battery terminal: In this case using only 8 volts; four cells of the battery. Join the switch terminal to the positive terminal of the 8 volt battery. As soon as the solenoid has pulled into engagement, remove the wire from the field terminal. The solenoid should hold in engagement.

1

2

A

17 Reassembiing the starter 1 Reassembly is the reverse of dismantling. 2 The armature bushes should be lightly oiled with engine oil. The other parts should be smeared with general purpose grease.

FIG. 10.4. UNDERCUTTING

3 The armature should have end-float of 0.004 - 0.015 inch

A the correct way

(0.1 - 0.4 mm). This is adjusted by the thrust washer at the gear

B the incorrect way

end. The pinion shaft should have end-float of 0.004 - 0.012

7 Insulator

inch

(0.1 - 0.3 mm). When

engagement

the solenoid pulls the gear into

the clearance between the pinion and the stop collar

should be 0.012 - 0.060 inch (0.3 - 1.5 mm).

THE COMMUTATOR

2 ees

Copper segments

121

Chapter 10/Electrical system eee

18 Windscreen wiper motor 1 The windscreen wiper motor is in the scuttle at the top of the bulkhead behind the engine. Access is given by a pair of plates either side of the bonnet catch. These plates also give access to the windscreen washer piping. 2 For fault finding just the right hand plate need be taken off. To remove the motor, both must be removed.

3

Remove the series of set screws round the edge of the plates.

Prise undone the clips holding the brake pipes to the plates. 4 Lever out the top edge of the plate. Once it is clear, swing it

over, leaving the cable still in the bracket. (photos) 5 The wiring of the motor is now accessible for fault-finding. 6 If the motor has to be removed, it is easiest to take it out complete with all the linkage, though this means disturbing the weather seals at the wiper pivots. The mountings for the motor on the linkage are very inaccessible. 7 Remove the nuts holding the wiper arms to their spindles, and pull off the arms. Undo the nuts clamping the pivots to the scuttle, and take off the sealing blocks. 8 Unplug the wires from the motor. Undo the two bolts through the resilient mounting below the motor, holding the bracket to the car. 9 Swing the pivots out of their holes, and thread the assembly clear. 10 The wiper motor should be overhauled in similar manner to that described for the starter motor. The pivots of the lever mechanism should be lubricated with molybdenum disulphide

18.4a These covers give access to the wiper mechanism

grease. 11 After putting back the assembly, position the motor mounting and pivots so that the weather seals can fit snugly, and the mounting is not strained so that the links will have to bend, and stiffen the operation. Before putting on the arms, run the motor to get it to the self-park position, then fit the blades in

their parked place near the bottom of the glass, but not so close they will hit the edge when in use, so get worn.

18.4b After prising out they can be

swung down without unclipping all the cables from them

19 Lamps

1 The lamps vary markedly to suit the different regulations in various countries. When getting a replacement sealed beam unit or bulb it is best to take the old one to check the new is the same pattern. It is recommended that spare bulbs for parking, brake, and turn lights be carried on the car. 2 To give access to the headlamps, the front grille must be removed by undoing the securing screws. 3 Access to the tail lamps is from inside the boot. The bulb holders should be turned to release their catches. (photos)

18.4c The plastic waterproof cover has been removed for this photo. Wrap up

20 Turn indicator flashers

1 Failure of a bulb will be shown by a change in the speed of flashing, and the note of the clicking. Failure of the flasher itself is usually complete, sticking with the lamps unlit or lit. 2 The flasher unit is under the dash. Access is possible direct, but it is easier to remove the dash panel completely. (See

the motor so no wet can get in

Chapter 12/14).

21

1

Instruments

Access

to

the

instruments

is gained

by

removing

the

dashboard as described in Chapter 12. The tachometer measures the engine speed by counting the low tension circuit to the leading coil. 2 The fuel and temperature gauges have their senders whose electric resistance varies according to the circumstances they are recording. The temperature gauge sender is on the rear of the water pump, just below the thermostat. The fuel gauge sender is ‘ : é

mounted

in the top of the tank, with access through a plate in

18.7 Hold the wiper arm before using the spanner, so no stress is put on the

linkage

eee

122

oS Mh

MLA

K Nn

Pg)

Bl

1,

|©»|Stop lamp

ei

Turn signal lamp

Wiring Renal colour code

Stop & tail lamp Reverse lamp

il ih

9 ee

Interior wt

ll

fiFuel pump Heated rear window

License lamp

Stop & Tal lamp Turn s@gnal lamp Reverse lamp

Example:

BR

G : Green B : Black

Black

Red

Y : Yellow W : White

Wiring diagram for all sedan/saloon models

Red

128

Head

Head lamp

Front turn

lamp

Front turn

signal lamp — Fog lamp

senal lamp

Side turn signal lamp 3.4W

]

SEsSTS

, Oil

a

tom

BN

pressure switch

Alternator

Ignition coil relay

Water temprature Gauge unit Screen Washer

Starter motor

Flasher unit

~