Chilton's General Motors Full-Size Trucks 1988-98 Repair Manual [28624] 0801991021, 9780801991028

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28624

'

FULL-SIZE TRUCKS 1988-98 REPAIR

MANUAL

Covers all U.S. and Canadian models of Chevrolet/GMC Pick-Ups, Sierra, Blazer, Tahoe, Yukon and Suburban; 2 and 4 wheel drive, gasoline and diesel engines

t

f?

7*\. -'

Fig.

16 Screwdrivers should be kept to prevent injury or

good condition age

wtiicli

could result

if

in

the blade slips

punches and

chisels,

knuckles ruining the bolt and often harming your

use the proper size and type

Do

wrench or socket straight, not

that fits the nut or boll.

Do be

.

hand.

Do

a vehicle

supported using salety stands

The wrench or socket should

that the force is

deep

into

around

rather than

push on

it,

a

ana

fall.

of the fixed jaw,

hammer; avoid glancing blows,

Do

strike squarely with a

Do

drive wheels set the parking brake and block the

if

the

your body

A

fail

or

bump

work requires a

.

,„

wrap

a spinning shaft or fan.

Don't

gasoline, cleaning solvent or other

smoke when working around

Don't

charged,

it

,.,^

smoke when working around gives

off

the battery.

,.

When

.

„

the battery

„i^:„„ being

is

explosive hydrogen gas.

excellent soaps avail. Don't use gasoline to wash your hands; there are additives which can enter the body through a able Gasoline contains dangerous natural oils from the the all also removes cut or through your pores. Gasoline oil and grease. skin so that bone dry hands will suck up you are equipped with . Don't service the air conditioning system unless the necessary tools

running engine.

.

can drive a screwdriver

can Even a rag hanging from your back pocket

flammable material.

sit

,

^

Don't use pockets for toolboxes.

.

.

on a wrench handle

on the side

under a hat or cap.

.

select a

closed on the nut or bolt sure that adjustable wrenches are tightly

and pulled so .

the process.

^

adjust your stance to prevent a .

in

ol tool for the job at

cocked,

Do, when possible, pull

.

is

and grip on slippery surfaces Watches soles protect your toes and give a better vehicle. Long hair should be tied back jewelry is not safe working around a

cracked sockets, slipping worn screwdrivers, spread wrenches (open end), can cause accidents. ratchets, or laulty droplight sockets „ ^ „ . . can slip ott a bolt heaa, wrench greasy . Likewise, keep your tools clean; a

.

NEVER work under it

(jackslands)

hammerheads, mushroomed properly mainlain your tools. Loose excessively Irayed or poorly grounded electrical cords,

Do

18

unless

a nut

from the screw

.

Fig.

17 Using the correct size wrench will oil help prevent the possibility of rounding Fig.

dam-

/\t

When

and training

released to atmospheric pressure

This

will chill or freeze

anything

it

it

will

liquid or

compressed gas

refrigerant is

absorb heat from whatever

it

contacts.

touches.

other than driving screws! A screwDon't use screwdrivers for anything least expect it, causing used as an prying tool can snap when you good screwdriver. injuries At the very least, you'll rum a ratchet, scissors, or pantograph . Don't use an emergency jack (that little anything other than changing a "at' These lack supplied with the vehicle) for use out on the road; they are NU jacks are only intended for emergency serious about maintaining your vehidesigned as a maintenance tool. If you are least a V/2 ton capacity, and at in a hydraulic floor jack of at .

.

Don't run the engine in a garage or

anywhere else without proper ventitime to leave

it takes a long lation— EVERi Carbon monoxide is poisonous; deadly supply of it in your system by the human body and you can build up a not realize you are slowly poisimply breathing in a little at a time. You may windows, fans and/or open the soning yourself. Always use power vents,

garage door. .

wearing loose clothing, bhort Don't work around moving parts while with neoprene much safer than long, loose sleeves. Hard-toed shoes

driver

cle yourself, invest least

two sturdy jackslands

sleeves are

FASTENERS, MEASUREMENTS AND CONVERSIONS Bolts, Nuts

and Other Threaded Retainers

» See Figures 19 and 20 found in the modem car or Although there are a great variety of fasteners fastener (nuts, bolts^ most commonly used retainer is the threaded may be reused, provided that they screws studs etc), IVlost threaded retainers repair. Some retainers (such as stretch are not damaged in use or during the designed to deform when tightened or in use

truck the

I

m

bolts or torque prevailing nuts) are

and should not be

reinstalled.

which should be Whenever possible, we will note any special retainers always inspect the condition of a replaced during a procedure. But you should any that show signs of damage. Check retainer when it is removed and replace

LOCKWASHERS

increase the torque necessary to threads for rust or corrosion which can that fastener was originally selected. achieve the desired clamp load for which fastener has not been comAdditionally be sure that the driver surface of the cases a driver surface may promised by rounding or other damage. In some driver to catch in only one direcbecome only partially rounded, allowing the and tightened, many of these occurrences, a fastener may be installed

©

all

(§)

tion. In

but the driver If

would not be able

you must replace a

ALWAYS

to grip

fastener,

and loosen the fastener again. to design or damage, you must

whether due

be sure to use the proper replacement.

In all

cases, a retainer of the

Fig.

19 There are many different types

on vehicles

of

threaded retainers found

GENERAL INFORMATION AND MAINTENANCE

1-6

B

DIameler (major diameler)

C Threads per Inch D Thread lengrh -

or

mm

E Size of the wrench required F - Root diameter (minof diameter) -

ICCS1038 IL.LblUJ«

20 Threaded retainer sizes are determined using these measurements Fig.

Fig. 21

Various styles of torque wrenches are usually available at

your local automotive supply store

same

design, material and strength stiould be used. Markings on the heads ol

most

bolts will help determine the proper strength ot the fastener. material, thread and pitch must be selected to

Click (Breakaway) Type

The same Another popular design of torque wrench

assure proper installation and

safe operation of the vehicle afterwards.

is

the click type. To use the click

type wrench you pre-adjust

it to a torque setting. Once the torque is reached the wrench has a reflex signaling feature that causes a momentary breakaway of the torque wrench body, sending an impulse to the operator's hand.

Thread gauges are available to help measure a bolt or studs thread Most automotive and hardware stores keep gauges available to help you select the proper size. In a pinch, you can use another nut or bolt for a thread gauge If the bolt you are replacing is not too badly damaged, you can select a match by finding another bolt which will thread in its place. If you find a nut which threads properly onto the damaged bolt, then use that nut to help

Pivot >

Head Type

See Figure 22

select the

replacement

bolt.

Some torque wrenches (usually of the click type) may be equipped with a it to be used in areas of limited access. BUT it must be used properly To hold a pivot head wrench, grasp the handle lightly and as you pull on the handle, it should be floated on the pivot point. If the handle comes in contact with the yoke extension during the process ol pulling there is a very good chance the torque readings will be inaccurate because this could alter the wrench loading point. The design of the handle is usually such as to pivot head which can allow

WARNING

:!"!:

Be aware

that

when you

damaged threads you may it was threaded into has also been you may have to drill and tap the hole

tind a bolt with

also find the nut or drilled hole

damaged.

It

this Is the case,

replace the nut or otherwise repair the threads.

replacement

bolt to

fit

into the

damaged

NEVER

try to force a

make

it

inconvenient

threads.

to deliberately

misuse the wrench.

^It should be mentioned that the use of any U-joint, wobble or extension will have an effect on the torque readings, no matter what type of wrench you are using. For the most accurate readings, install

It

would be tightening a threaded retainer such as a nut. bolt or screw Measuring is one ot the most common ways to help assure that

torque

a threaded retainer

has been properly fastened.

When

tightening a threaded fastener, torque

the head, the bearing surface

sured torque

is

used

in

and

the

clamp

is

load.

applied

in three distinct

About 50 percent

of the

the socket on the wrench driver. If necessary, straight extensions (which hold a socket directly under the wrench driver) will have the least effect on the torque reading. Avoid any extension that alters the length of the wrench from the handle to the head/driving point (such as a crow's foot). U-joint or wobble extensions can greatly affect the readings- avoid their use at all times. directly

Torque

is defined as the measurement of resistance to turning or rotating tends to twist a body about an axis ot rotation. A common example of this

areas

mea-'

overcoming bearing

friction. This is the friction between the bearing surface of the bolt head, screw head or nut face and the base material or washer (the surface on which the fastener is

rotating).

Approximately 40

percent of the applied torque is used in overcoming thread friction This leaves only about 10 percent of the applied torque to develop a useful clamp load (the force which holds a joint together). This means that friction can account for as much as 90 percent of the applied torque on a fastener.

TORQUE WRENCHES >

See Figure 21 In

most applications, a torque wrench can be used to assure proper installaTorque wrenches come in various designs and most automo-

PIVOTED HANDLE TORQUE WRENCH

tion of a fastener. tive

TCCS1041

supply stores

will carry a variety to suit your needs. A torque wrench should be used any time we supply a specific torque value for a fastener Again the general rule of "if you are using the right tool for the job, you should not have

22 Torque wrenches with pivoting heads must be grasped and used properly to prevent an incorrect reading Fig.

to strain to tighten a fastener" applies here.

Beam Type

Rigid Case (Direct Reading)

A

The beam type torque wrench

is one of the most popular types It consists of a pointer attached to the head that runs the length of the flexible beam (shaft) to a scale located near the handle. As the wrench is pulled, the beam bends and the pointer indicates the torque using the scale

to

rigid

case or direct reading torque wrench

show torque

values.

One advantage

of these

is

equipped with

wrenches

a dial indicator

is that they can be held at any position on the wrench without affecting accuracy These wrenches are often preferred because they tend to be compact, easy to read and have a

great degree of accuracy

GENERAL INFORMATION AND MAINTENANCE CONVERSION FACTORS

ih;;

lORQUf ANGLI:

LfNOTH-OISTANCe each laslener or thieaded hole

wil

vary,

Because Itie Irictional characterislics ot applicaon torque will vary as well In most clamp loads which are based strictly But. in certam applicasignificant enough to cause worry. lions this variance is not loads are clamp Precise ™'e may determine that necessary (such

is

VOLUME

engineers

tions; a manufacturer's

the case with

STangie method ol

many aluminum

installation

would be

cylinder heads),

IMPPIfliillMPin)

installing las eners

When

specilied.

these cases, a

Iri

predetermined seating torque and standard which are torque angle tightened, a Ihe remove any compliance Irom the |Oint. loioue wrench are usually used first to in additional portion of a turn measured fastener

is

5^. A

then tightened the specified protractor) torque angle gauge (mechanical

is

used

for

these applications lS0.11oo.(USMil

Standard and Metric Measurements »

See Figure 23 Throughout

manual, specifications are given

this

to help

deteriiiine the

you

your vehicle, or to assist you m their condition of various components on common measurements include length (m or

Some

installation

cm/mm) Hg)

torque

of the

lbs.,

(ft.

most cases, we

In

most

Nm) and pressure (psi, in. Hg, kPa or mrn determined provide the proper measurement as

inch lbs. or

strive to

by the manufacturer's engineers.

Thouoh what

in

some

.

cases, that value

with not be conveniently measured

may

Luckily, is available in your toolbox.

many

of the

measuring devices which

riieasurescales so the Standard or (Metric are available today will have two various measuring tools which are ments may easily be taken. If any of the specifications, in the the same scale as listed available to you do not contain to determine the proper value. the accompanying conversion factors

use

and

given specification factor chart is used by taking the the factor. For instance looking at by the necessary conversion should be 2 in inches such as "free-play line if you have a measurement conversion the in by multiply 2 millimeters, but your ruler reads only in

The conversion multiplying first "

in

factor of

tion

it

25 4

of to get the metric equivalent

was given only

(Nm), then look ply

column

the center

50.8mm.

measurement, first.

If

tor

the

NUMBER

Likewise,

example

in

if

the specifica-

Newton Meters

measurement

to get 73 8 by the conversion factor of 0,738

it

SERIAL

>

at

in a IVIetric

is

100 Nm, multi-

lbs

ft

IDENTIFICATION

See Figures 24 and 25 The Vehicle

of the

Identification

instrument panel, and

Number is

(VIN) plate

is

mounted on the

driver's side

visible through the windshield.

trucks including the Tahoe,

size C/K The models covered in this book are full renamed in 1992 the Blazer was Jimmy, Yukon and Suburban. Starting Jimmy/Yukon. the Jimmy the Blazer/Tahoe and number is the vehicle line and The 5th digit on the vehicle identification Blazer,

chassis type: .

C and R are 2-wheel

.

V and K

Fig.

drive conventional cabs

cabs are 4-wheel drive conventional

24 The Vehicle Identification Number (VIN)

the windshield

is

visible through

1

Ha

- ui~iii

1-7

1-8

GENERAL INFORMATION AND MAINTENANCE VEHICLE IDENTIFICATION CHART

GENERAL INFORMATION AND MAINTENANCE

Mi

m slls

lllltllllH

llll^

i

a?

111 If

HillH

|i lift 111, III till

fgltiti

'5^5

.sills

1-9

GENERAL INFORMATION AND MAINTENANCE

1-10 On On On

the

NP231. NP233 and NP241,

the

NV241 and NV243. it is attached to the Warner 4401/4470. it is attached

attached to the rear case

is

it

hail.

I

'

rear case half.

the Borg

to

an extension housing

bolt

Service Parts Identification Label »

See Figure 27

is

usually located on the inside of the glove compartment door.

The service parts

identilication label,

you may have to look

trucks,

for

on

all

special equipment. Probably, the

all

as the option

3^^^^

list,

On some

on an inner fender panel. The

it

the vehicle serial number, wheelbase,

and

commonly known

label lists Ptim technology

Regular Production Options (RPOs)

most valuable piece

this label is the paint code, a useful item

of information

when you have occasion

84901020

need

to

Fig.

paint.

27 Service parts identification label

ROUTINE MAINTENANCE AND TUNE-UP Proper maintenance and tune-up life.

shown

Studies have

is

the key to long and trouble-lree vehicle

that a properly

tuned and maintained vehicle can

owner and

log to jot

down which

services you performed,

and the exact odometer reading

items as engine

problems or

to

and

oil

filters,

The

In

the light. filter.

If

no glow

of light

If

holes

the

filter

in

can be seen through

filter

element are apparent

are evident, replace the

filter.

so

at

that they

later.

Keep your own personal

how much

the parts cost you,

the time. Keep

may be

all

such

receipts for

referred to in case ol related

determine operating expenses. As a do-it-yourselfer, these

you have

receipts are the only proof

formed.

filter at

or signs of dirt seepage through the

aside a Saturday morning, say once a month, to check or

driver, set

replace items which could cause major problems

the date,

and look through the

the element material, replace the

achieve better gas mileage than an out-of-tune vehicle. As a conscientious

that the required

maintenance was per-

the event of a warranty problem, these receipts will be invaluable.

literature

provided with your vehicle when

includes the factory this literature,

it

was

originally delivered

recommended maintenance schedule.

If

you no longer have

replacement copies are usually available from the dealer.

Air Cleaner 1.

»

See Figures 28, 29 and 30

wing Nut Hole Cover Cleaner Assembly Cleaner Extension TBI Assembly

2. 2

3. Air 4. Air

The element should be replaced Maintenance

at the

recommended

Intervals chart later in this section.

If

changes

will certainly

and

Early spring

early

element and check

housing or in

for

signs of

for

be necessary Inspect the element fall

are always

good times

any perforations or tears

dirt or

dust that

may have

is

the

at least

1-

3.

4 5

Fig.

the

5.

filter.

twice a year

Remove

Check

leaked through the

through the snorkel tube. Position a droplight on one side

2

in

operated under

more frequent

lor inspection.

in

shown

intervals

your truck

severely dusty conditions or severe operating conditions,

the

the cleaner lilter

ol the

element

M901023

Fig.

29 Exploded view

of tlie air

cleaner fiousing— 1993 gasoline

engines

element

cleaner Seal Exlension

Aif

Slud Nul 18 inch lbs

28 Typical

-

air

gasoline engines

cleaner housing assembly components

—1988-92

Fig.

30 Exploded view

engines

of the air cleaner

housing

—6.2L

diesel

GENERAL INFORMATION AND MAINTENANCE

uj ec UJ

S^

" ~

1-13

Fuel Filter

See Figures 31. 32, 33, 34 and 35 REtVIOVAL & INSTALLATION

On oldei model vehicles, loosen Ihe wingnut(s) and lit! oil the housing On newer model vehicles, unfasten the retaining clips and separate the

1.

cover

Carbureted Gasoline Engines

Iwo case halves

On

2,

olf to

the 6,5L diesel. position the cover

vi/ith

the air cleaner flexible

hose

FILTER IN

CARBURETOR

the side

3 4,

Withdraw the element Irom the housing and discard With a clean

rag,

remove any

dirt or

>

it.

dust from Ihe front cover and also

The

from the element sealing surface. install:

5.

Position and install Ihe nevt

filter

element so

that

it

seats properly

in

the

On

the 6,5L diesel. position the cover with the attached

hose over the

early

model

vehicles, install Ihe housing

wingnul(s) to about 18 inch

8

On

Filter

late

model

lbs. (2

fuel fittings to

al

the interval given

of fuel fillers are used, a

on the Maintenance

bronze type and a paper ele-

replacement should be altempled only when Ihe engine It

is

a good idea to place

catch the gasoline which will

is

some absorbent rags under Ihe out when the lines are loos-

spill

ened.

element and snap the retaining clips into place.

On

ment type

should be serviced

Two types

cold Additionally.

housing,

7.

fuel filter

Interval chart

To

6

See Figure 36

lid

1

and tighten the

Disengage the

opening

Nm).

vehicles, place the housing cover into position

and engage

2

wrench

the retaining clip

WARNING

connection

fuel line

al

the intake fuel

tillef nut.

Plug tne

to prevent loss of fuel

Remove

the intake fuel

filter

nut from Ihe carburetor with a

1

in

open end

(or adjustable wrench).

3,

Remove

4

Check

the

filter

element and spring.

the element for restrictions

by blowing on the cone end Air

should pass freely

Do

not drive the vehicle with air cleaner

removed. Doing so

will

dirt and a variety of other foreign particles to enter the engine and cause damage and wear. Also, backfiring could cause a fire in

allow

the engine compartment.

5

To 6 filters

Clean or replace Ihe element, as necessary. install: Install the

element spring, then the

filter

element

8798IP01

Fig. 31

Loosen the wingnut and remove

from the

air

cleaner cover

^SZ,

it

in the

carburetor Bronze

should have the small section of the cone facing out.

87981 POj

Fig.

33

ment

Remove

the old air cleaner ele-

.

, ..

GENERAL INFORMATION AND MAINTENANCE

1-14

new gasket on

Install a

7.

body and

Install the fuel line

8.

ttie

intake fuel nut. Install the nut in the carburetor

and tighten the connector.

may have an inline between the pump and

trucks

the fuel line

plastic or metal.

To replace the

some absorbent when removed.

Place

1

gasoline

Use a

2.

ber hose.

Do

the

same

This

the carburetor.

new

Installed with a Install the

4.

It

may be made

new

Inspect the

Remember,

filter.

the point to

which the

filter

will

it

ol the

be

pipe extends

with the other clamp. filter

pipes.

Remove and

come

with

new

dis-

filter

for leaks with the

tioses that should be

clamps back

into the hoses, slide the

engine

Appalt a tew drops of clean engine

new

9.

Tighten the housing by turning

filter

cartridge

%

clockwise

it

Connect the negative battery cable.

1 1

Start the

12

Repair as necessary

engine and check

filter

>

on the

for fuel leaks.

See Figures 40 and 41 The fuei/water separator

is

usually located on the header

Drain the fuel from the fuel

fuel injected

models

is

found along the frame

2.

Remove

3.

Unstrap both

To

rail.

4.

used on the V6 and V8 engines contains a constant bleed feature in the pressure regulator that relieves pressure any time the engine is turned off. Therefore, no special relief procedure is required, however, a small amount of fuel may be released when the fuel line is disconnected. To reduce the chance of personal unit

in

filter

Remove install:

bail

wires with a screwdriver and remove the

Before installing the

4.

Install the filter

fuel lines

new

filter,

insure that both

new

snap

Install the

6.

Close the water drain valve and open the I.D.

hose

filter,

to the air

7.

Disconnect the

8.

Crank the engine to cool.

Repeat

engine

>»The

test the truck

filter

to

20

and check

has an arrow

sure to Install

bolt.

9.

Close the

and replace the

and tighten the ft.

bolt to lbs.

for

12

ft.

lbs.

(16 Nm). Connect the

tit-

into place with the bail wires. air

bleed valve. Connect a Va

fuel injection

for

pump

shut

off

10-15 seconds, then

solenoid wire.

wait one minute for the starter

observed coming from the

manifold which could result air

air bleed.

be cranked, or starting attempted with the air in

dirt

from being pulled

engine damage.

bleed valve, reconnect the injection

pump

solenoid wire

fuel tank cap.

Start the engine, allow

it

to idle for

5 minutes and check the fuel

filter for

leaks.

leaks.

6.5L (fuel flow direction)

on the side

of the case,

correctly in the system, the with arrow facing

it

10.

(26 Nm).

any

mounting plate

filter

bleed port and place the other end into a suitable

until clear fuel is

is to

into the air inlet

from the retainer or mounting

and tighten the nuts

Road

5

filter

in the tank.

filter.

dirt.

5.

'^If the

fuel lines.

the fuel

bleed and the

vacuum

the fuel tank cap to release any pressure or

cleaner removed, care must be taken to prevent

3

air

install:

(3mm)

motor

cover the fuel line with cloth to collect the fuel and then in an approved container.

To

assembly

by opening both the

container.

place the cloth

Disconnect the

into position.

gasket seats, then

water drain valve allowing the fuel to drain out into an appropriate container.

CAUTION

2

housing

until the

turn.

10.

tings are clear of

injury,

new housing gasket and

the

oil to

and the place the

Install a

and

Properly relieve the fuel system pressure.

The 220 TBI

signs of corrosion or damage, replace as

6.2L ENGINE into place,

idling.

See Figures 37 and 38 inline filter

for

8.

1

1

cartridge.

housing

Diesel Engines

EXCEPT CARTRIDGE TYPE

The

filter

filter.

Fuel Injected Gasoline Engines

>

filter

tighten the housing an additional

the rub-

in

housing and gasket from the base.

filter

the fuel

install the gasket.

full of

then

filter,

the

install:

7.

filter:

rags under the

filters

Remove Remove

6.

To

of either

filter.

••Most replacement

fuel to drain into

necessary

a can-shaped device located in

is

Gently twist and pull the hoses free of the

3.

card the old

check

filter.

5.

4.

expand the clamp on one end

pair ot pliers to

clamp down past

slide the

housing counterclockwise and allow the

filter

a suitable container

INLINE FILTER

Some

Turn the

3.

tighten securely.

ENGINE

be

away

»

See Figure 42

from the fuel tank. 1

CARTRIDGE TYPE »

See Figure 39

Fig.

Disconnect the negative battery cable.

37 The fuel

frame

rail

filter is

found along the

vacuum

the fuel tank cap to release any pressure or

in

the tank.

equipped, remove the upper intake manifold cover,

If

3,

Open

4,

Spin

the air bleed valve off

on top

of the filter

the element nut at the top of the

assembly

filter

—

it

looks

like

a large

knurled knob,

Properly relieve the fuel system pressure. 2.

Remove

2,

5,

Fig.

38 Using two

flare nut

connect the fuel lines

Lift

the

filter

wrenches, dis-

element out

of the

Fig.

header assembly

39 The cartridge type

located along the frame

fuel filter Is

rail

,

GENERAL INFORMATION AND MAINTENANCE

1-15

To Install: b Ifie

CiiMii

surfaces o' "

iimIiiuj

lilt;

widest key slot

'

•

Disconnect the

•

'-adet

•

Align

nul by hand.

tfte

to

into a suitable glass container

pump shut-down

fuel injection

tfie filter

assembly, pusti the

lighten

'

assembly Connect a hose

oi ti.e liiiei

end

and

"iBIy

•

'

the bleeder valve and insert the other 8.

'

the element c-n

in

element down until the two surfaces 7 Open the air bleed valve on top

solenoid wire or the

FUEL SOL relay center fuse (whichever applies to your in 10-15 second intervals until clear clean tuel

vehicle, then crank the

engine

is

coming out

ol (he

hose

•^Walt about one minute between cranking Intervaltl

Remove

9

1

Water drain vatw«

2 Bail wires 3 Fuel liller elemen

6 Air bleed port

4 Air bleed

8 Fuel tieater

5

Filter

7

engine and allow

cap

lor leaks

PCV Valve >

See Figure 43

9 Water sensor

adapter

40 Exploded view

install the fuel

lew minutes Check

to idle (or a

it

Restriction swrtch

M9D103I

Fig.

the hose and close the bleeder valve

Connect the shut-down solenoid wire or fuse and

10

Start the

of the fuel filter—6. 2L

^Diesel engines do

engines

The

PCV

is

the heart ol Ihe positive crankcase ventilation sys-

tem, should be changed as noted ol this section. ol dirt

FUEL FILTERWATER SEPARATOR

c>

FILTER INLET

FUELFILTERWATER "SEPARATOR

The main thing

m

the

keep in

When

the valve

Maintenance Intervals chart

in

mind

is that

at the

or

gummed

becomes

sticky

up.

and

end

the valve should be free

working order As long as the valve

becoming damaged

ol

function properly.

HOSE

to

and residue and should be

showing signs

f^FWD

PCV system.

not utilize a

which

valve,

it

should perform

will

is

not

its

not operate freely,

it

should be replaced.

PCV

The

•

valve

used

is

to control the rate at

which crankcase vapors are

returned to the intake manifold The action of the valve plunger

is

controlled

by intake manifold vacuum and the spring. During deceleration and manifold vacuum

plunger bottoms

it

it

overcomes the tension

when

and Ihe

reduces, but does not stop, the passage of vapors to the

When

the engine

is

lightly accelerated or

speed, spring tension matches intake manifold takes a mid-position

idle,

of the valve spring

manifold end of the valve housing. Because of the

in the

valve construction, intake manifold.

high,

is

in

operated

at

constant

vacuum pull and the plunger more vapors to flow into the

the valve body, allowing

manifold

Fig. 41 Fuel filter/water separator

—6.2L engines

The valve

is

either

mounted on

the valve cover or in the line which runs from

the intake manifold to the crankcase. valve.

If

the valve is faulty, replace

Do

not attempt to adjust or repair the

it.

NUT fLEMENT ASSEMBLY. ELEMENT ASSEMBLV, HEADER .

SEAL,

WATER SENSOR

ASSEMBLY. WATER SENSOR

SCREW, SENSOR MOUNTING SEAL CAP ASSEMBLY HEATER NUT CAP CAP AlH BLEED

REMOVAL & INSTALLATION t

See Figures 44 and 45 1

Remove

the

PCV

valve from the cylinder head cover or from the mani-

fold-to-crankcase hose.

Fig.

42 Exploded view

of the fuel filter

—6.5L engines

2.

Visually inspect

deterioration

all

hose connections and hoses

and replace as necessary

for cracks,

clogs or

GENERAL INFORMATION AND MAINTENANCE

1-16

Fig. Fig.

44

PCV

Pull the

valve out of

45 Disconnect the PCV valve from the

hose and remove the valve from the vehi-

tlie cylin-

der head

cle

Crankcase Depression Regulator and Flow Control

The evaporative emission canister compartment, with a

located

filter

COR valve— 6.2L

46

Fig.

located on the

is

bottom

in its

(if

left

engine

side of the engine

applicable),

Valve f^For further information on the evaporative emission system, please refer to Section 4.

SERVICING To service the canister 1,

I

See Figures 46 and 47

»This system

Loosen the clamps and remove the and throw

Pull the filter out

The Crankcase Depression Regulator (CDR) crankcase vapors

in tiasically

engines The valve the valve and

The and

is

the

designed

is

same manner as

the

PCV

to

ventilation pipes

scavenge

On

this

new

Install a

valve on gasoline

located by the right cylinder head cover.

are replaced as an

filter

hoses, tagging them as necessary

of the

in

case any have to be removed.

found only on diesel engines.

is

filter:

Note the installed positions

canister

Install the canister

system,

canister.

away

it

filter.

and tighten the clamps.

Check the hoses.

assembly

and tubes should also be cleaned and replaced as wear

tear dictates,

w^Do not attempt

to test the cranl(case controls

on these diesels.

assembly and vent pipes and check the vent pipes. Replace the breather cap assembly every 30,000 miles (48.000 km). Replace all rubber fittings as required every 15,000 miles Instead, clean the valve cover filter

(24,000 km).

PRECAUTIONS Always use caution when working on or near the battery Never allow a

ground between the positive cable/termi-

careful not to allow a tool to provide a

and any metal component on the

nal

cause

Do

vehicle. Either ot these conditions will

a short circuit, leading to sparks

not

smoke

or

battery; the

gases contained

in

could cause severe injury or death.

ignited,

it

regardless of type, should be carefully secured by a battery

All batteries,

hold-down device vehicle operation,

discharge

and possible personal injury

open flames/sparks near a

all

the battery are very explosive and,

it

tool

bridge the gap between the negative and positive battery terminals. Also, be

to

faster.

not, the terminals or

If

A

battery

which

Always inspect the battery case

If

the battery

eat

away

lor cracks,

at

may may

crack from stress during

allow acid to leak, making

components under the hood.

leakage and corrosion,

on nearby components would

sive substance on the battery case or

ing or cracked battery.

casing

not secured

is

The acid can also

is

cracked,

it

A

white corro-

indicate a leak-

should be replaced immediately

GENERAL MAINTENANCE Always keep the battery cables and terminals Fig.

47 CDR valve

—6.5L engine

clean these

components about once a

Keep the lop

be used

Evaporative Canister

any

of the battery clean, as a tilm of dirt

used

tery that is not

free of corrosion.

for long periods,

lor cleaning, but

Check and

year.

A solution

be careful to flush this

of the solution into the tiller holes.

can help discharge a bat-

of

baking soda and water

olf

with clear water,

may

DO NOT

let

Baking soda neutralizes battery acid and

will de-activate a battery cell.

Batteries in vehicles

SERVICING

which are not operated on a regular basis can

parasitic loads (small current drains battery).

The only regular maintenance emission canister vi/hich utilize

one;

is

to regularly

1991-98

condition of the hoses. are is

If

that

need be performed on the evaporative

change the

filter

(on those 1988-90 models

trucks do not have a canister

filter)

and check the

any hoses need replacement, use only hoses which

marked EVAP. No other type should be used. Whenever the vapor vent hose

replaced, the restrictor adjacent to the canister should also be replaced.

Normal

or

may

tall

victim to

which are constantly drawing current from the drain a battery on a vehicle that

is in

storage

6-8 weeks. Vehicles that have additional accessories such as a an alarm system may discharge a battery sooner, the vehicle is to be

and not used

phone

parasitic loads

for

II

stored for longer periods

in

a secure area and the alarm system

is

not necessary,

the negative battery cable should be disconnected to protect the battery.

Remember

that constantly

and recharging

tt)

will

deep cycling a battery (completely discharging

shorten battery

life.

GENERAL INFORMATION AND MAINTENANCE BATTERY FLUID >

Check

Battery electrolyte contains sulfuric acid

Ihe battery electrolyte level at least

weather or during periods ies,

cell

cell, or

add only

low,

is

on your skin or often in

level in

the line

clear wafer.

each

should be kept

tilled to

case

ol the

through the opening

Each

must be checked and

cell

tilled

your eyes, gel medical help immedi-

In

The

many

fluid (suffuric acid solution)

contained

submerged below

extremely important And, because the specific gravity of the acid tion ol electrical charge, testing the Ifuid

added

in freezing weather, the

can be an aid

in

an indica-

determining

il

the bat-

its life

tery is

is

most drinking

in

water are harmful to the battery and could significantly shorten water

you

the lluid level in order to operate, Ihe fluid level is

individually Distilled water

should be used, because the chemicals and minerals lound

II

in Ihe battery cells will tell

things about Ihe condition ol the battery Because the cell plates must be

until the level

kept is correct.

lands

II it

translucent) or by

marked on the outside

distilled water

II you should splash any your eyes, flush the allecled area with plenty ol

In

fiot

ately.

caps The electrolyte

cell

Ihe level

more

or

extended vehicle operation On non-sealed batter(if

Ihe split ring inside each II

ol

once a montti,

the level can be checked either through Ihe case

removing the

CAUTION

\"\:

See Figure 48

1-17

vehicle should be driven several

must be replaced A

system should require

battery in a vehicle with a properly operating charging

maintenance, but carelul. periodic inspection should

little

miles to allow the water to mix with the electrolyte. Otherwise, the battery could reveal

problems before they leave you stranded.

(reeze

At least once a year, check the specific gravity of the battery

Although some maintenance-free batteries have removable

cell

caps, the

between electrolyte condition

checked using the But,

most

and

level

built-in

on

all

sealed maintenance-free batteries must be

hydrometer "eye." The exact type

of

eye

20 and

1

1

26 on the

gravity scale

each

to test Ihe specific gravity in

cell.

battery manufacturers, apply a sticker to the battery itself explaining

The

has a squeeze bulb

battery testing hydrometer

the other Battery electrolyte

^Although

the readings from built-in hydrometers will vary, a green eye

usually indicates a properly charged battery with suflicient fluid level.

normally an indicator

iark eye

is

which

low

trolyte

charge.

in

A

light or

A

from If

The

seat

gravity

low

is

checked again

yellow eye usually indicates that elec-

specific gravity

has dropped below the necessary level.

In this last

case, sealed

must usually be discarded.

battery

in

sucked

is

into the

one end and a nozzle

at

hydrometer

at

until the lloal is lifted

specific gravity is then read by noting the position ol the float

one or more

to see

if

cells, the battery

the gravity has

between any two

should be replaced, as

it

come

cells varies

should be slowly charged and

up. Generally,

il

after

more than 50 points

charging, the (0.50), the

can no longer produce sufficient voltage to

guarantee proper operation.

Checking the Specific Gravity

CABLES

See Figures 49, 50 and 51 >

A hydrometer

is

required to check the specific gravity on

not maintenance-free. is

its

of a battery with sufficient fluid, but

batteries with an insufficient electrolyte

I

variety ol

will vary.

the readings

is

should be

It

Most auto stores carry a

inexpensive battery hydrometers These can be used on any non-seale

See Figures 58, 59, 60, 61 and 62

smooth from slippage, while a good

visible. All

Cracks

worn

or

used— 90

ft

lbs.

(122 Nm);

V8—6.2176.5L diesel: used—67 belt is considered

ft.

lbs.

new— 169 lbs. (229 Nm). lbs. (197 Nm). (90 Nm); new— 146

"used" after 15 minutes

ft,

ft.

of operation.

Serpentine Belts

Inspect the belts tor signs of glazing or cracking, fectly

6—4.8L:

A

glazed belt

will

be per-

The serpentine belt will

have a slight texture

belt tension

can be checked by simply observing the belt

of fabric

acceptable belt wear range indicator located on the tensioner spindle. will

usually start

damaged

at

the inner edge of the belt and run outward.

drive belts should be replaced immediately

does not meet the specified range, It

is

best to

it

must be replaced.

If

the belt

.

GENERAL INFORMATION AND MAINTENANCE

Fig.

58 There are typically 3 types

ol

60 Deep cracks

Fig.

accessory drive belts found on vehicles

flex, building

today

lead

1-19

in this belt will

up heat that

cause

will eventually

to belt failure

Nippondenso BoiTough$

f Fig. 61

The cover

exposing the

of this belt Is

critical reinforcing

worn,

Fig.

cords

to

excessive wear

62 Installing too wide a

result in serious belt

belt

can

wear and/or break-

age

63

Fig.

Common

belt tension

gauges

REMOVAL & INSTALLATION •ELT DEFLECTION

V-Belts >

See Figures 65, 66 and 67

tTHAtCHT

EDGE

1

Loosen the driven accessory's pivot and mounting

2.

Install

Move

the accessory tov^ard or

a lever, but

do not use anything

bolt

correct.

an adjusting bolt to do

and

metallic,

this

work

It

such as a prybar. Certain models may Simply loosen the mounting

for you.

If

new

belts

have been

installed,

is

better to

have belts too loose than too in

tight,

the water

because overtight

pump and

alternator.

tielts will

However,

loose belts place an extremely high impact load on the driven component due to

64 Measuring belt deflection

the whipping action of the belt.

iJ-^^,

Fig.

Fig.

65 Push the component toward the

engine and

slip off the belt

belt.

run the engine for a few minutes, then recheck and readjust as necessary.

lead to bearing failure, particularly Fig.

the

the engine until

or broomstick, as

turn the adjuster.

Tighten the bolts and recheck the tension.

3.

Remove

bolts.

away from

You can use a wooden hammer handle,

is

utilize

MAKE SUAE RULER IS PEnPENDtCULAR TO STUAIOKT EOOE

the belt.

the tension

67 Pull outward on the component

and tighten the adjusting and mounting Fig.

66

Slip the

new

belt over the pulley

bolts

GENERAL INFORMATION AND MAINTENANCE

1-20

Serpentine Belts >

See Figure 68 1.

(AIR)

On

all

pump

models except

the 7,4L engine witti an Air Injector Reactor

(Calitornia emissions only), use a Vs

socket placed on

in.

breaker bar

witfi a

tensioner pulley bolt, rotate the tensioner to relieve belt

ttie

tension. 2.

On

suitable

all

7.4L engines

witti

an AIR

wrench on the pulley axis

pump

(California emissions only), use a

bolt to rotate the tensioner clockwise to

relieve belt tension. 3.

Remove

the serpentine

belt.

To install: 4.

Route the

5.

On

all

belt

over

all

the pulleys except the tensioner.

models except the 7.4L engine with an AIR pump

(California emis-

sions only), place the breaker bar and socket on the tensioner pulley bolt and rotate the tensioner to the released position. 6.

Install the belt

7.

On

suitable

all

and return the pulley

7.4L engines with an AIR

wrench on the pulley axis

to its original position.

pump

(California emissions only), use a

bolt to rotate the tensioner clockwise to

relieve belt tension. 8.

Install the belt

9

Check

and return the pulley

to

its

that the belt is properly seated in

original position

each pulley

Fig.

70 Drive

belt

routing— 1988-90 5.7L and 6.2L engines

GENERAL INFORMATION AND MAINTENANCE

A

RV

1-21

21 (w A/C)

50 CoolAni

Pump

Pulley

51

Cranunan PuNay

52

QtmUoi

Pul«v PoMWt SMvrtng Pump PuiWy 55 All Cond«or«ng ComprMMX Puli«v 54

Fig.

73 Drive belt routing— 1991 6.2L engines. R/V series

'

A

4 31.. SOL. STL Engines With Power Steenng Pump

B With Power 1.

2 3 4 5 6

K Pa 6 26 HO (W

P/S. P'S

7 8

Pump)

B P3 4 3L. 5 7L (W P/S) C P3 5 7L {WP-S and ACt

Mt

Ain

9.

Pump

'

E F.

Idler Pulley

Steering

Pump

and A/C Compressor With Powrer Steenng Pump and Alfl Pump With Power Steering Pump and AIR Pump arxl A/C Compressor

C

Condiltoning Compcossof Tenstooer Qeneraior Pottw Steering Pump Crankshaft Coolant Pump

Aif

6 2L Diesel Engirtes With Air Conng With Air ConOitK)ning or Vlicuum Pump or Idtor

PuMy

50 Coolant Pump Pulley Si Cranluhan Pulley S2 Genecaioi Pulley 54 Power Sleenng Pump Pulley 55 Aw Conekbomng CompresscK 56 idtoiPuney

F^Jlley

Fig. Fig.

74 Drive beit routing— 1991 6.2L

76 Drive

C/K series

HD and 4.3L engines

2

7 I

See Figures 89, 90, 91 and 92 radiator tioses along wilti the healer

Upper and lower checked

and

and loose hose clamps

lor delerioralion. leaks

miles (24.000 km)

is

II

beginning ol the

at Ihe

hoses should be

at least

every 15,000

also wise to check the hoses periodically or winter

tail

when you

in

early spring

are performing other mainte-

nance A quick visual inspection could discover a weakened hose which might have

CrtMAfTfOU.rr-'

you stranded

lelt

Whenever you

il

it

had remained unrepaired

are checking the hoses,

tem are cold. Visually inspect

make sure

lor cracking, rotting or

collapsed hoses, and replace

as necessary Run your hand along the length of the hose Fig.

86 Drive bell routing— 1996-98 4.3L. 5.0L and 5.7L engines

*;C

spot

is

and cooling sys-

the engine

II

a

weak

or swollen

noted when squeezing Ihe hose wall, the hose should be replaced

COMPRESSOR ENGINE WITHOUT KI9

IOl£RPUU£V

QENERATOR

Fig.

89 The cracks developing along this hose are a result

age-

of

related hardening

REMOVAL & INSTALLATION >

See Figures 93, 94, 95 and 96 1

Remove

the radiator pressure cap.

CAUTION

Fig.

87 Drive

belt

routing— 1996-98 7.4L engines C/K series

Never remove the pressure cap while the engine is running, or personal injury from scalding hot coolant or steam may result. It possible, wait until the engine has cooled to remove the pressure cap. If this is not possible, wrap a thick cloth around the pressure cap and turn it slowly to the stop. Step back while the pressure is released from the cooling system. When you are sure all the pressure has

been released, use the cloth - */C COMPflESSOfl

2.

to turn

and remove

ttie

cap.

Position a clean container under the radiator and/or engine draincock or

open the drain and allow the cooling system

plug, then

ate level. For

some upper

hoses, only a

little

to

dram

A/C

COMPRESSOR

the entire cooling

to

an appropri-

coolant must be drained. To

remove hoses positioned lower on the engine, such as a lower

radiator hose,

system must be emptied.

lOLER PULLEY

CAUTION

GENERATOR

When

draining coolant, keep

in

mind

that cats

and dogs are

attracted by ethylene glycol antifreeze, and are quite likely to drink

any that

is left in

an uncovered container or

ground. This will prove fatal

SECOND GENERATOR

88 Drive bell routing— 1996-98 diesel engines

Always drain

may be reused

unless

it

contaminated or several years old. 3.

Clamps Fig.

puddles on the

in sufficient quantity.

coolant into a sealable container. Coolant is

in

Loosen the hose clamps

at

each end

of the

hose requiring replacement.

are usually either of the spring tension type (which require pliers to

squeeze the tabs and loosen) or

hex drivers

to loosen). Pull the

of the

screw tension type (which require

saew or

clamps back on the hose away from the connection.

GENERAL INFORMATION AND MAINTENANCE

1-24

My Fig.

90 A hose clamp that

cause older hoses

to

is

ICCS1222

too tight can

Fig. 91

separate and tear on

clamp

either side of the

A

soft

spongy hose (identifiable by

Fig.

92 Hoses are

likely to deteriorate

the swollen section) will eventually burst

from the inside

and should be replaced

periodically flushed

if

the cooling system

is

not

Bead

\

Approximately 1/4 inch

Fig.

93 Remove the radiator cap

Fig.

94 Loosen the hose clamps

end

of the

at

each

hose requiring replacement and

Fig.

remove the hose

is

To

95 Position the hose clamp so that

about Vi

in.

from the end

of the

it

hose

install:

6.

Dip the ends of the new hose into clean engine coolant to ease installation.

7.

Slide the clamps over the replacement hose, then slide the hose ends

over the connections into position. Position and secure the clamps at least Va

8.

oi the

Make

hose.

9.

(6.35mm) from the ends

in.

sure they are located beyond the raised bead of the connector.

Close the radiator or engine drains and properly

refill

the cooling sys-

tem with the clean drained engine coolant or a suitable mixture col coolant

10.

If

and

available, install a pressure tester

tester is not available, run the

reached (allowing the system :•;:•=

of ethylene gly-

water.

engine

until

and check

for leaks.

If

a pres-sure

normal operating temperature

to naturally pressurize), then

check

is

for leaks.

CAUTION

for leaks with the system at normal operating not to touch any moving or Once temperature has been reached, shut the engine OFF, and check for leaks around the hose fittings and connections which were removed earlier. If

you are checking

temperature, BE

EXTREMELY CAREFUL

hot engine parts. Fig.

96 Properly

refill

the cooling system with a suitable mixture of

ethylene glycol coolant and water

4.

Twist, pull

the neck of the

»lf the hose

and

slide the

hose

off

component from which is

the

fitting,

the hose

is

taking care not to

damage

CV-Boots

being removed.

stuck at the connection, do not try to insert a screwdriver

or other sharp tool under the hose end in an effort to free

it,

as the con-

may become damaged. Heater connections especially may be easily damaged by such a procedure. It the hose is to be replaced, use a single-edged razor blade to make a slice along the por-

INSPECTION

nection and/or hose

tion of the

end

hose which

of the hose.

tion.

Do

is

stuck on the connection, perpendicular to the

not cut deep so as to prevent

damaging the connec-

The hose can then be peeled from the connection and discarded.

>

See Figures 97 and 98 The

the oil

CV is

boots keep water, grime, CV-joints,

5.

Clean both hose mounting connections. Inspect the condition

hose clamps and replace them,

if

necessary.

of the

(Constant Velocity) boots should be checked for

changed and any other time the vehicle

Any

expensive to

of

dirt

is

damage each time

raised for service.

These

and other damaging matter from entering the

these could cause early CV-joint failure which can be

repair.

Heavy grease thrown around the inside

of the front

wheel(s) and on the brake caliper/drum can be an indication of a torn boot.

GENERAL INFORMATION AND MAINTENANCE Tlioioughly check Ihe boots

aged,

It

lot

missing clamps and leais

should be replaced Immediately Please

the boot

II

Section 7

refer lo

is

dam-

km) As

the

gap increases, Ihe plugs voltage requirement also increases

requires a greater voltage to

proce-

lor

much

dures

voltage to

ratio control of

modern

Spark Plugs >

on a

lire

Ihe wider

the plug at high

modern

ignition

|ump

fuel iniection

systems

will often

gap and about two

speeds than

typical spark plug consists ol a metal shell

A

lator

metal electrode extends

and protrudes

a small distance.

the side ol the outer metal shell

bends

90'' in at a

angle so that

surrounding a ceramic insu-

downward through Located

at the

end

the center of Ihe insulator ol the

plug and attached

keep

in

mind

its tip is

just past

and

of

an inch or hundredths

1

2

parallel to the tip ol the

of a millimeter) is called the

3.

which the current can volts

coil

to

50,000

(depending on the type and application) which travels through the wires to

The current passes along the center electrode and jumps the

the spark plugs.

gap

The

arc.

produces anywhere from 20.000

to the side electrode,

and

in

doing so, ignites the

air/luel

mixture

in the

combustion chamber.

to

by remov-

nay become

if

Ihe vehicle has been run

Be sure

lo pull

Using compressed

air,

it,

then pull upward and

on the boot and not on the

may become

wire,

separated

blow any water or debris Irom the spark plug well

Ihe spark plug is removed.

If

compressed

air is

not available, use

a rag or a brush to clean Ihe area

•^Remove the spark plugs when Ihe engine is cold, vent damage to the threads. If removal of the plugs base

of

penetrating

of the plug,

oil

and allow

it

possible, lo pre-

is difllcult,

or silicone spray to the area it

Using a spark plug socket

a

lew minutes

that is

apply a

around the

to wortc.

equipped with a rubber

insert to prop-

erly hold the plug, turn the spark plug counterclockwise to loosen

Figure 100

drop as

assure that no harmlul contaminants are allowed to enter the combustion

chamber when

4.

>See

the boot from the plug

lew drops

SPARK PLUG HEAT RANGE

start

thoroughly cool

to

otherwise the connector located inside the boot

gap.

The spark plug does not produce a spark but instead provides a gap across

engine

Carelully twist the spark plug wire boot to loosen

remove

spark plug

Doni

a time

once, because, unless you number them, they

Disconnect the negative battery cable, and

recently, allow the

center electrode. The distance between these two electrodes (measured in

thousandths

all at

that efficiency will

at

mixed up Take a minute before you begin and number the wires with tape

to

the side electrode The side electrode

is

ing the plug wires

as

air/Iuel

the higher voltage oulpul ol

economy and power)

When you're removing spark plugs, work on one A

The improved

at idle

combined with

It

lo three times

allow an engine to run signKicanlly longer

set of standard spark plugs, but

Ihe gap widens (along with luel

See Figure 99

1-25

and remove

the spark plug Irom Ihe bore

Spark plug heat range

is

the insulator (or the larther

the ability ol the plug to dissipate heat. it

extends into the engine), the hotter the plug

operate: the shorter the insulator (the closer the electrode ing passages) the cooler

remains too cool not hot

enough

misfiring,

A

will

to

it

will operate.

A

oil.

^^^^f^K^\iM\

oil

will

much

heat will have

WARNING

the block's cool-

little

and carbon since

no deposits

but,

use a flexible extension on the socket. Use ol a llexiallow a shear force to be applied to the plug. A shear force could break the plug off In the cylinder head, leading to

Be sure not

heat and it

is

This leads to plug tooling and consequently to

plug that absorbs too

the excessive heat, the electrodes will burn

'.^.Jr

is to

plug that absorbs

quickly accumulate deposits ol

burn them

The longer

due

away quickly and might possibly

lo

to

ble extension

may

costly and frustrating repairs.

GENERAL INFORMATION AND MAINTENANCE

1-26 To install:

8

Inspect the spark plug boot lor tears or damage.

5.

II

a

damaged boot

found, the spark plug wire must be replaced.

Using a wire

6.

feeler

washer.

gauge, check and adjust the spark plug gap.

When

using a

should not be able to pass while the next smaller size should pass

Carefully thread the plug into the bore by hand.

7.

plug

Is

If

resistance

is felt

9.

before the

is

:•::::

supple enough

to twist before

it

If

you are

Apply

tlie

would allow

amount

of silicone dielectric

compound

spark plug socket to thread

ttie

plugs. Always care-

until

it

clicks into place.

The

f

n nq

deposits and wear.

Remember

which can sometimes be found

normally worn

I

tor

of the

install

may be

the

felt

they are not going to be replaced,

If

thai

any kind

efficiency of the plug. Plugs can be cleaned in

A

spark pluq should have liqht Ian or gray deposits on the tip

of deposit will

service stations, or you can do an acceptable

carbon fouled

plug. Identified by soft, sooty, black

deposits, may indicate an improperly tuned vehicle. Check the air cleaner,

This spark plug has been led in the engine loo long, as evidenced by the extreme gap- Plugs with such an extreme gap can cause misliring and stumbling

accompanied by

igni-

An oil fouled spark plug indicates an engine with worn poston rings and/or bad valve seals allowing excessive oil

to enter

the

chamber.

a

noticeable lack of power.

physically damaged spark plug may be evidence of A

severe detonation

in

that cylinder. Watch that cylinder carefully between services, as a contin-

ued detonation will not only damage the plug, but could also damage the engine.

determine engine running conditions

decrease the

on a spark plug cleaning machine,

tion components and engine control system

to

click

See Figures 101, 102, 103. 104 and 105

clean the plugs thoroughly

and damaging the cylinder head bore.

101 Inspect the spark plug

end

INSPECTION & GAPPING »

A

Fig.

to the

the plug to crossthread.

thread the plug by hand or using an old plug wire to prevent the

possibility of crossthreading

equipped

or heard, then gently pull back on the boot to assure proper contact.

In

WARNING

not use

installing is

and boot could be used as a

Check the plugs

Do

fully

you are

installing a tapered seat plug, tighten the plug to specifica-

a small

boot to the spark plug and push

threading tool. The boot will hold the plug while you twist the end of the wire and the wire

the plug

spark plug lead or inside the spark plug boot to prevent sticking, then

freely.

almost completely threaded, back the plug out and begin threading again.

small, hard to reach areas, an old spark plug wire

II

tions provided by the vehicle or plug manufacturer.

gauge, the proper size should pass between the electrodes with a slight drag. The next larger size

Carefully tighten the spark plug.

with a crush washer, seal the plug, Ihen tighten about V« turn to crush the

is

bridged or almost bridged spark plug. A

Identified by a buildup between the electrodes caused by

excessive carbon or oil build-up on the plug.

.

GENERAL INFORMATION AND MAINTENANCE

li

1-27

^

f

L.t

See Figure 120 Tires

tire's

must be

rotated periodically to equalize

position on the vehicle. Tires will also wear

wear patterns in

that vary with a

an uneven way as the front

steering/suspension system wears to the point where the alignment should be

^

reset.

Rotating the tires will ensure

ADAPTERS

not have to discard a rotation

is

tire

early

maximum

due

to

life

for the tires

wear on only

as a

set,

so you

wilt

pari of the tread. Regular

required to equalize wear

IC

Fig.

When

117 Most altermarket blades are available with multiple

same adapters to

fit

rotating "unidirectional tires,"

direction. This

means

that a tire

dlHerent vehicles not be switched to the right side

make sure

used on the

that they left

and vice-versa. Such

always

roll in

side of the vehicle tires

the

must

should only be

Front

t

} Fig.

118 Choose a blade which

will

fit

(FOR NON DIRECTIONAL TIRES

(FOR DIRECTIONAL TIRES

AND WHEELS)

AND WHEELS)

your

119 When

vehicle, and that will be readily available

Fig.

next time you need blades

blade

is tutly

installed, be certain the

inserted into the backing

Fig.

120 Compact spare

be used

in

tires

must NEVER

the rotation pattern

GENERAL INFORMATION AND MAINTENANCE

1-34

on

rotated Iront-to-rear or rear-to-lront, while always remaining

These

tfie vetiicle.

tion;

marked on the sidewall as

tires are

observe the marks when reinstalling the

Some

styled or

"mag" wheels may have

same

ttie

side ol

these wheels are equipped with unidirectional tire is

remounted

ol the vehicle

snow

the

tires are installed,

and drive accordingly

^Consider buying extra wheels on which to mount the snow tires. Once done, the "snow wheels" can be installed and removed as needed. This

if

damage

eliminates the potential

wheels from seasonal

to tires or

they cannot be rotated

tires,

removal and

Even

installation.

your vehicle has styled wheels, see

if

inexpensive steel wheels are available. Although the look is strictly for

emergency use.

change, the expensive wheels and pothole damage.

will

It

the tire rotation or placed on the vehicle for

in

if

proper direction of rotation.

for the

(•The compact or space-saver spare

must never be included

Once

of the vehicle.

tire(s).

different offsets front to rear. In these

cases, the rear wheels must not be used up front and vice-versa. Furthermore,

unless the

and braking characteristics

ing

you must re-learn the behavior

to the direction ol rota-

be protected from

will

ot the vehicle salt,

curb hits

everyday use.

STORAGE

TIRE TIRE

DESIGN

See Figure 121 For

should be used

satisfaction, tires

in

sets of four. Mixing of dif-

should be avoided.

(radial, bias-belted, fiberglass belted)

most cases, the vehicle manufacturer has designated a type

the vehicle will perform best. Your

use the same type of

When to

tire that

first

tire.

choice when replacing

the manufacturer

radial tires are used, tire sizes

maintain ground clearance and

specified

should be kept

All tires

brands or types

ferent In

maximum

tire

ol tire

basement, do not

wood,

should be

a

recommends.

t

sets of tour.

in

See Figures 122

employs

air

air at

to the original size as

marked on

the

P-IWetric This allows the exact identification of the less of the manufacturer.

while the vehicle

is

selecting a different

If

tire for

any sign

tire

remember

to

with the body or suspension

can produce a big advantage

does not have

snow, a

street radial tire

control.

The small grooves

behaves

like a billiard ball

snow

tire will

sufficient tread to provide traction

of a street tire quickly

on a marble

slippery weather, but

in

floor.

pack with snow and the

in

A

and

hours.

The more open, chunky tread

self-clean as the tire turns, providing

much

better grip

A

of a

on snowy

tires carry either

M+

an

tires

necessary when buying snow

In

after the tire size

the opposite

hose

much

at

your corner garage

abuse. Always check

end

ol the vehicle

tire inflation,

is

hood, tailgate or trunk

tire

nec-

compartment: an tire

pres-

pressure when the tires

do not drive more than a mile before checking.

normally provided somewhere lid)

ai' out).

This

will

not accurate

is

you must move the vehi-

If

more than

cause the

tire to

off air

three

(door post,

in the vehicle

which shows the proper pressure

counteract excessive pressure build-up by bleeding

for the tires. I^ever

pressure (letting

run hotter and wear quicker.

general, no

change

CAUTION

stamped on in tire size

Never exceed the

tires.

Most manufacturers strongly recommend the use vehicles for reasons of stability

some

during weather emergencies,

S designahon

the sidewall, or the designation "all-season."

lose

tire will

fixture in every glove

generally one that has not been driven for

tire is

plate or sticker

some

To satisfy municipalities requiring snow

is

cold

tire

surfaces.

most snow

permanent

a

of the air

suffers too

it

check the

cle to radial tires

A

of air periodically is not

are cold, as pressure increases with temperature.

Tires

Good

add a few pounds

sure (including the spare) regularly with a pocket type gauge. Too often, the

because

Snow

to

tire.

pressure gauge and a tread depth gauge. Check the

tire

tire

designed around the supporting

perform as intended.

tire's ability to

Two items should be

gauge on the end

stopping, turning sharply or heavily loaded.

is

It

a specified pressure. For this reason, improper inflation

essarily a sign of a leaking

accurate

cannot be overemphasized. A

tire inflation

structure.

its

day-to-day use; having

air in tire,

specifications, regard-

size or brand,

tire

ot interference

127

thru

proper

of

as part of

strength of the

described using an industry size code sometimes referred to as

check the installed

strips of

newspaper. Keeping them away from direct

of

INFLATION & INSPECTION

drastically reduces the

tvlost tires are

the garage or

position.

flat

The importance

pay attention

in

them on

and wheel diameters should be selected

Radial tires should never be used on only the front axle.

tires,

floor; set

load capacity equivalent to the original

Radial tires should always be used

selecting

they are stored

If

them stand on a concrete

let

paramount importance. Tires should not be stored upright, but

of

is

store the tires at proper inflation pressure.

a cool, dry place.

to

CAUTION

When

in

mat or a large stack

a

moisture

on which

in

tires

mounted on wheels,

they are

It

>

of

4

snow

tires

on

This

their

snow tires are fitted only to the drive wheels, may become very unstable when braking or

maximum

tire

the pressure to be used

is

ing, but

it

is

pressure embossed on the

when

the tire

is at

tire!

maximum

load-

rarely the correct pressure for everyday driving. Con-

It

turning on slippery surfaces. This instability can lead to unpleasant endings

sult the tire

owner's manual or the

tire

pressure sticker for the correct

pressure.

if

the driver can't counteract the slide in time. f>Jote

snow

that

snow

situations.

tires,

The

whether 2 or

stiffer,

heavier

4, will affect

snow

vehicle handling

tires will noticeably

in all

change the

turn-

the correct tire pressures for several weeks, you'll

Once you've maintained

non-

be familiar with the vehicle's braking and handling personality. Slight adjust-

ments

in tire

pressures can fine-tune these characteristics, but never change

the cold pressure specification by ETRIC TIRE SIZES

sure

will

tire will

more than 2

psi.

A

slightly softer tire pres-

A

give a softer ride but also yield lower fuel mileage.

slightly harder

give crisper dry road handling but can cause skidding on wet surfaces.

Unless you're

fully attuned to the vehicle, stick to the

recommended

inflation

pressures.

V2

have built-in tread wear indicator bars that show up as

All

automotive

in.

(13mm) wide smooth bands across

tires

the

tire

remains. The appearance of tread wear indicators replaced.

In fact,

many

when Vie

means

in.

(1.5mm)

that the tires

of tread

should be

states have laws prohibiting the use of tires with less

than this amount of tread.

You can check your own

tread depth with an inexpensive

gauge or by using a

Lincoln head penny. Slip the Lincoln penny (with Lincoln's head upside-down) into several tread grooves.

grooves, the replaced.

Fig. 121 P-Metric tire

coding

tire

If

you can see the top

has less than Vie

You can measure snow

side of the Lincoln

penny

time to replace the

snow

It

in. (1

.5mm)

tires in the

tread

left

head

in

2 adjacent

and should be

same manner by using

you can see the top

tire(s).

of Lincoln's

of the Lincoln

the "tails"

memorial,

it's

GENERAL INFORMATION AND MAINTENANCE

1-35

KMUWm WU«

Fig.

122

Common

lire

wear patterns and causes

S:;

•

RADIAL TIRF

Fig.

TCCS1096

Fig.

123 Tires with deep

wtiich bulge, should be replaced

tires

have a characteristic

sure by looking at the

Immedi-

air pressure

ately

Fig.

124 Radial

sidewall bulge: don't try to measure pres-

cuts, or cuts

tire.

Use a quality

Fig.

125 Tread wear indicators

when

gauge

the tire

is

will

appear

worn

126 Accurate tread depth Indicators are inexpensive and handy

FLUIDS AND LUBRICANTS

Used

fluids

fluids, consult with etc. is

begin with

such as engine

are hazardous wastes and

oil,

transmission

must be disposed

your local authorities;

in

(luid, antifreeze

of properly.

many

areas, waste

being accepted as a part of recycling programs

and brake

fluid

Before draining any oil,

A number

antifreeze,

will

of tfie recycling center's policies before draining

any

to

known as

fluids,

as

meaning they

"straight weight",

many

10W-40 means 10 weight

oil,

lubrication.

that in winter (the

ideal in cold

oil

lubrication

would therefore be

will

to the oil viscosity chart tor oil of

Automotive Engineers (SAE) grade number indicates the vis-

cosity of the engine

oil; its

resistance to flow at a given temperature.

The lower

The American Petroleum engine

oil

it

choose when changing the be operating

oil

engines

internal

and not as

offer better protection at higher

50 weight

make sure you

in until

the

oil

Whichever

are anticipating the

changed again. Refer

oil is

recommendations according

Institute (API)

The

acts like a straight

for the

acts like a

oil,

etc

acts like a thin

offering rapid

slightly heavier than

weather as the 10W-40, but would

viscosity you

temperatures your engine

I See Figures 128. 129 and 130

however the

up,

oil

when cold and

and protection

rpm and temperatures because when warm oil

such as 10W-40, 20W-50,

the designation) the

in

Once the engine has warmed

components. A 20W-50

OIL

The Society

"W"

allowing the engine to spin easily

40 weight, maintaining good

Recommendations

and do not

Multi-viscosity oils offer the important advantage of being adaptable to temperature extremes. These oils have designations

not accept different fluids that have been mixed together.

Fuel and Oil

are of a single viscosity,

vary with engine temperature.

of service sta-

tions and auto parts stores are also accepting waste fluids for recycling.

Be sure

SAE grade number, the lighter the oil. For example, the mono-grade oils SAE 5 weight, which is a thin light oil, and continue in viscosity up SAE 80 or 90 weight, which are heavy gear lubricants. These oils are also

the

Fluid Disposal

to temperature.

designation indicates the classification of

used under certain given operating conditions. Only

oils

designated for

GENERAL INFORMATION AND MAINTENANCE

1-36 MOT WEATHER

HOT WEATHER

.^^3i% API

UE ;

(^

5*M

10W

"'^^°

SERVICES

M IF

NEITHER SAE 5W-30

NOR SAE 10W.30 GRADE OILS ARE AVAILABLE. SAE 30 GRADE MAY BE USED AT TEMPERATURES ABOVE 40*F (4'C)

SH,'CD.SG,SF.CC I

RETURN USEO

OIL TO

SAE 15W-40 PREFERRED

SAE 10W'30

DON'T POLLUTE. CONSERVE RESOURCES

COLLECTION CENTERS

(^ COLD WEATHER

Do Not Use SAE 10W-40 Grade Oil or

Not

any Other Grade

Recommended

84901084

Fig.

128 Gasoline engine

chart

oil

viscosity

Fig.

129 Look

label

for the

API

oil

identification

when choosing your engine

oil

Fig.

130 Diesel engine

oil

viscosity chart

GENERAL INFORMATION AND MAINTENANCE Sometimes becomes necessary to it more than a lew

pings, knacks or runs on. switch lo a higher grade ol luel. just

changing brands

problem

will cure the

II

It

Remove

•

oil

from skin by washing thoroughly with soap and water or

waterless hand cleaner

change

retard the timing from speclllcatlons. don'l

•

1-37

Do

not use gasoline, thinners or other solvents

Avoid prolonged skin contact with oil-soaked clothing

degrees. Retarded timing will reduce power output and luel mileage

and

will

» See Figures 131, 132 and 133

Diesel engines require the use ol diesel luel At no lime should gasoline be

Two grades o( diesel luel are manulactured. No 1 and No 2. No 2 grade is generally more available Better luel economy results Irom the use ot No 2 grade luel In some northern parts ol the US and in most parts ol Canada, No 1 grade luel is available in the winter or a winterized blend ol No. 2 grade is supplied in winter months. When the temperature tails below

Every time you stop

substituted

although

20F {-70. No,

1

grade or winterized No, 2 grade

be used Cold temperatures cause unwinterized gels), blocking the fuel lines

• • • It

Do Do Do is

home

luel are the

No

(it

actually

heating

oil in

not use any luel additives

It

is

that the

engine noise

level is louder

also normal that whitish/blue

alter starting

use

in

gasoline engines

during the warm-up period

and during warm-up The amount

of

Open

3

the

smoke depends upon

level

the

hood and

best lor the engine to be at operating

is

it

oil

immediately

locate the dipstick its

should be between the

OIL marks on

5

tube, wipe

which

it

If

the

oil is

FULL

or

it

»

below the

ADD

mark, add

Fig.

131

Remove

check the

Fig.

oil

the

oil

dipstick

ot the cylinder

Reinsert the dipstick and check the

Irom the

134 With the proper

loosen the drain plug

size socket,

head cover See the

oil

tiller

ADD

to the

FULL, Excess

and Fuel

rating ol

again

oil level

oil will

alter

one quart

generally be

adding any

oil.

Be

of oil will raise the

consumed

at

an

should be changed every 7500 miles (12,000 km) General Motors the

oil filter

be changed with every

oil

Fig.

Fig.

132 Remove the

Fig.

135 Remove the drain plug while

oil filler

with every other

change There

133 Using

is

to

from running out prematurely

keep

Fig.

136 With

oil filter

oil

change; we suggest that

approximately

a funnel,

grade and viscosity

cap

maintaining a slight upward force, oil

'Oil

and

& FILTER CHANGE

The

the

the

or

rate,

and

level

ADD

and

the proper viscosity through

oil ol

See Figures 134. 135. 136 and 137

oil:

oil

side ot lf« it

horizontally, read the oil level

OPERATING RANGE

on the lop

OIL

Avoid prolonged skin contact with used motor

left

the dipstick

recommends changing •

on the

chart in this section tor the proper viscosity

level

when handling used motor

will lead to

oils,

accelerated

ple precautions

is

Recommendations' acceptable

6

CAUTION

stopping

clean and reinsert

careful not to overfill the crankcase Approximately

Prolonged and repeated skin contact with used engine oil. with no eftorl to remove the oil, may be harmtul. Always follow these sim-

after a

the capped opening

the outside temperature.

•::•:

as follows;

oil

ground,

oil level

Pull the dipstick out again and. holding oil

ADD

smoke may be emitted Irom

check the engine

for fuel,

engine Pull the dipstick from

The lor

on

checking the

drain back into the crankcase

4

your truck,

recommended

f'ark the truck

When

a lalse reading Wait a few minutes after turning off the engine to allow the oil to

only fuels that can

2 to thicken

1

2

temperature, although checking the

and preventing the engine Irom running,

not use ether or starting assist fluids in your truck,

normal

in winter.

exhaust

not use

CHECK

OIL LEVEL

Increase the engine temperature.

Diesel Engines

1

quart ot

add the proper

of oil

a filter

wrench, loosen the

counterclockwise

.

.

GENERAL INFORMATION AND MAINTENANCE

1-38

Open

12

a container ol

new

gasket of the ter

by hand

oil filter.

until the

new

Get a

oil

and smear some where the

feel lor

ol this oil

filter

gasket contacts the seat. Turn the

post

is

onto the rubber

and

start the

fil-

%

an addilional

filter

turn with your hand. 13.

Install the drain

enough

threads. Over time the drain plug

is.

plug and metal gasket. Be sure that the plug

does not leak

that the oil

you

will

out. but not tight

a torque wrench

If

enough

is tight

to strip the

develop a sense of what the proper tightness of

18

available, tighten the plug to

is

It.

lbs.

(25 Nm),

^Replace

the drain plug gasket at every third or fourth

Through a suitable

14.

plastic or metal funnel,

proper grade and viscosity through the sure that the Fig.

137 Before installing

with clean

new

a

coat

oil filter,

tlie

rubber gaslcet

oil level

Install

16.

Start the

mark on the

registers near the (lull)

and tighten the

15.

oil filler

engine and allow

it

on the top

oil filler

change.

oil

add clean new

oil of

the

ol the valve cover.

Be

dipstick.

cap.

to run for several minutes.

Check

for leaks

oil

and drain plug. Sometimes leaks

at the filter

will not

be revealed

until the

engine reaches normal operating temperature. remaining

dirty oil left

seems

every year

in the old oil filter

every time you change the

filter

The

drain plug

oil

if

not changed!

is

it

a small price to pay for extended engine

is

A lew

—

life

more

dollars

When you

located on the bottom, rear of the

pan (bottom

oil

of the

The mileage

your truck

If

road conditions, change the

same goes

and

oil

oil after

normal operating temperature. Hot be removed along with the

and

filter:

oil

it

it

oil

have

oil

the

flow

oil

more

from the

freely

mark. This

3.

Stop the engine. Raise the hood and remove the

the dipstick, wipe

it

Position a suitable

off

oil

will

and

set

it

cap from the oil

drains.

movement

of the oil

when

in

the pan

is

•

NVG 4500: Castro! Syntorq GL-4 NVG 5LM60: Syncromesh Transmission Fluid NVG 3500: Syncromesh Transmission Fluid

With the proper size socket or wrench (DO

messy

deep

keep the

to

it

NOT

use pliers or vise grips),

oil

Irom running out around

it

(and your hand). Allow the

dram pan

drain into the

Fluid

the lubricant level at least twice a year, even

more

frequently

if

driven

water.

With the truck parked on a

level surface,

remove the

filler

plug from the

side of the transmission case. Be careful not to take out the drain plug at the

bottom. 2.

If

lubricant begins to trickle out of the hole, there

fully insert a finger

oil spills.

loosen the drain plug. Back out the drain plug while maintaining a slight upward

oil to

it

See Figure 138

edge

to the

force on

117mm: API GL-5,SAE80W-90 85mm: Syncromesh Transmission

Getrag

1

pulled from under the vehicle.

This will prevent time lost to the cleaning up of 5

recycling and dispose of

oil for

IVIuncie

Check

aside.

drain pan under the drain plug

»AII diesel and gasoline engines hold approximately 5-8 quarts of oil (give or take), so choose a drain pan that exceeds this amount to allow for

into

LEVEL CHECK »

oil filler

top of the valve cover. This allows the air to enter the engine as the

4.

it

gas station

pan.

oil

Park on a

level surface,

C

now possess

pour

at least

apply the parking brake and block the wheels.

2.

Remove

garage which accepts waste

•

•

by running the engine for a short period of time or

needle on the temperature gauge rises above the

until the

make

the

to

or anti-freeze containers. Then, find a

•

•

Warm

is

FLUID RECOMIVIENDATION

addition to the engine.

in

1.

it

oil

the

oil to fill

do with

Manual Transmission

be

to

as necessary.

to

it

more contaminants

drained, using the drain plug. Be sure to add enough

cooler

to bring

were drained cold. To change the

cooler, this will also

to

oil

there.

only for short distances.

enough

The best thing

Add

notice that you

will

off-

frequently than specified. The

traffic or

flow easier and

oil will

than

equipped with an

is

more

the engine has been running long

will

»lf the engine

filter

stop-and-go

lor trucks driven in

Always drain the

assuming normal

intervals

being used under dusty, polluted or

is

oil.

such as milk

plastic jugs, or service

recommended

figures given are the

oil level.

have finished this job, you

several quarts of dirty

oil!

engine, underneath the truck).

driving and conditions.

Stop the engine and recheck the

17.

so change the

3.

If

to bring 4.

not, it

add

enough.

If

not, care-

level is

to the

ft.

5LM60. Road

proper

lbs,

level.

You can also use

plug and tighten (40

to

17

a

test the truck

and check

for

any

common

(23

lbs.

ft.

Nm) on NVG 4500; and 44

Nm) on

kitchen baster. the Ivluncie

(60

Nm) on

level in the

manual

ft,

lbs.

and

the

NVG

leaks.

CAUTION The engine oil will be hot. Keep your arms, face and hands away from the oil as It is draining. Remove

6.

the drain pan and wipe any excess

oil

Irom the area around the

hole using a clean rag.

Clean the threads

7

any sludge deposits

from the

filter

With

9. filter off

the

that

of the drain

the

a

on

to the

filter

filter

oil

does not

10.

Remove

plug and the drain plug gasket to remove

may have accumulated.

Place the drain pan under the

8.

oil filter

location to prevent spilling any

oil

ground.

wrench, loosen the

post the rest of the

oil filter

counterclockwise and back the

way by hand. Keep

spill out. Tilt the filter into the drain

pan

the

filter

end up so

that

to drain the oil.

the drain pan from under the vehicle and position

it

off to

the

side.

With a clean

1 1

seal-

Make

remove

it

rag,

wipe

off

the

sure that the old gasket

is

filter

seating surface to ensure a proper

not stuck to the seating surface.

and thoroughly clean the seating surface

of the old

If

it

is,

gasket material.

Fig.

138 Use your finger

mission

up

and tube, or a squeeze bulb

sufficient lubricant with a funnel

Install the

Getrag; 30

is

(watch out for sharp threads) and check that the

ol the hole.

to

check the

oil

trans-

.

GENERAL INFORMATION AND MAINTENANCE has been running

DRAIN &REFIU

pulling a

No

intervals ate specllied lor

changing the tfansmission

lubricant, but

is

it

a

idea

deep

vi/ater

on a used

vetiicle,

one

ttiat tias

been worked

tiard, or

one driven

level surface

and

Remove wipe

operating temperature

3 Place a pan of sullicient capacity under the transmission drain plug

3.

Remove Remove

4

:•:

the upper

(till)

running

and

let

the dipstick (on newer models,

clean and reinsert

COLD

•

plug to provide a vent opening

the lower (drain) plug

the lubricant drain out

The oil will be hot! Be carelul when you remove the plug be taking a bath In hot gear oil.

It.

lbs,

or you'll

plug and tighten to (40

1

7

It

lbs

the fluid level should

the fluid level should

Early

COLD

Add

5

the fluid level

II

Nm) on'NVG 4500; and 44

Check the

lbs,

It,

Nm) on

to overfill

(60

the

level often

is

is

Reinstall the

that

it

to flip

up the handle

has been pushed

fall in

all

the

way m.

horizon-

it

this

range when the engine has been

fall

in this

range when the engine has reached

Overfilling will

it

gun

or squeeze bulb,

plug.

tiller

Run

the engine

and check

lor leaks.

The

Automatic Transmission

the

ADD

mark, the level should be

cold

not within the proper area on either side of the dipstick,

as you are

Approximately one pint

lubricant with a suction

:•"•: 7.

uv\;-

side to the dipstick

models have two dimples below

between these when the engine

the l\/luncie

Nm) on

(23

NVG 5LM60, 6.

you may have

Be sure

firmly

if

the dipstick and check the fluid level while holdirrg

pour ATF into the dipstick tube This

and Getrag: 30

'J-^'W tin'

normal running temperatures. 4

5

rti irjiit.y

only a short time

for

HOT

•

CAUTION

Install the drain

iii

thirty miniii-

parking brake

set the

models have a HOT and a

tally All

2.

It

Remove

Position the truck on a level surlace

1

about

lor

the lubricant should be first),

at

long period,

for a

down

cool

in

2

The vehicle should be on a

It

P and

mission Into

good

high speed

at

trailer, let

Park the truck on a level surlace with the engine

1

1-39

of

is easily

filling

done with

the transmission

the aid of a funnel.

Be extremely

careful not

cause slippage, seal damage and overheating.

ATF

will raise the level

from one notch

to the other

WARNING

fluid

on the dipstick should always be a bright red

color.

It

If

is

discolored (brown or black), or smells burnt, serious transmission troubles, probably due to overheating, should be suspected. The

FLUID

transmission should be inspected by a qualified service technician

RECOMMENDATIONS

to locate the

Use Dexron

lir or its

superseding

cause

of the burnt fluid.

fluid type.

DRAIN & REFILL LEVEL CHECK > >

See Figures 142, 143, 144 and 145

See Figures 139, 140 and 141 1

Check the

checked with the engine

Fig.

once a month. The

level of the fluid at least at

fluid level

139 Remove the dipstick

to

check the

transmission fluid level

Fig.

If

142 Loosen

all

the pan bolts

pan

The

fluid

fluid

should be drained with the transmission if

the truck

always easy without a

140 Hold the dipstick horizontally and

143

to drain

Fig.

the truck

check the

Fig.

,

change the

should be

normal operating temperature and running.

Pull

one corner of the fluid

is

raised

somewhat from

The transmission must be

Fig.

warm

It

is

easier to

the ground, but this level for

it

is

not

to drain properly.

141 Use a funnel to add transmission

fluid

fluid level

most

lift

of the

pan down

and remove the

Fig.

144 Remove the old pan gasket and

clean both gasket mating surfaces

.

.

GENERAL INFORMATION AND MAINTENANCE

1-40

FILLER PLUG

145 Remove the

Fig.

from the trans-

filler

Loosen

makes

messy, once

wipe

out,

it

you

Remove

5

and threads

risk leaving bits of lint

the

or strainer retaining bolts.

filter

400, there are two screws securing the

solvent and air dried thoroughly. The

Install

7.

Install a in

new gasket and

a

6.

new gasket on

Wipe

you use a rag

to

5.

Add

6.

When

Add DEXRON'III

8.

the Turbo Hydra-Matic

body A may be cleaned

strainer

The

or

18

bolts evenly to

amount in

Park,

of

ft.

is

gun or squeeze bulb.

up

to the

bottom

of the filler hole, install the

to specifications.

4401 and 4470 models: 18

.

NV241 and NV243 models: 35

lbs.

ft.

ft.

(25 Nm). lbs.

(47

Nm)

start the

engine and

let

Do it

not overfill.

ADD

mark.

warm up

oughly

Front axles use

idle.

Do

not

90 gear

through each position, holding the brakes.

must be drained

Add

fluid,

if

off.

Overfilling

{6mm)

necessary.

fluid level after the truck

the transmission.

in.

has been driven enough

the transmission

It

causes aerated

is

excess

transmission

slippage and probable damage.

and damage

its

>

III'

or

fluid type its

on models through 1994. On

superseding

fluid.

LEVEL CHECK See Figure 146 Check

the four wheel drive transfer case lubricant at least twice a year.

With the truck parked on a

rear of the transfer

level surlace,

remove the

filler

plug from the

case {behind the transmission). Be careful not to take out the

drain plug at the bottom. If

lubricant trickles out, there

and check

that the level is

up

to the

is

may

be added,

it

enough.

edge

wheel drive cases which should be V2 Lubricant

There

in.

not, carefully insert a finger

EXCEPT in lull time {13mm) below the hole.

of the hole,

necessary with a funnel and tube, or a

squeeze bulb.

TightentheplugtolSft.

If

lbs.

{25Nm).

is

is

SAE 80W-

lubricant available from dealers

not used, noise, uneven opera-

also a Posi-traction additive used to cure

well.

See Figures 147 and 148 The

bulb.

superseding

1995-98 models, use Dexron

Lubricant. Rear axles use

must use special

the special fluid

LEVEL CHECK

filler

or

will result.

oil

level in the front If

driven

in

and/or rear differentials should be checked

deep water

four

it

fluid level in the front axle

plug opening. The fluid level

RECOMMENDATIONS II*

If

warning sticker near the jack or on the rear wheel

twice a year

Transfer Case

Use Dexron

stores.

noise and slippage. Posi-traction axles have an identifying tag, as well as a

ward. The

FLUID

SAE 80W-90, GL-5 Gear

Posi-traction axles

to thor-

overfilled, the

fluid, resulting in

oil.

and most auto parts tion,

Check the

11

RECOMMENDATIONS

lbs.

transmission fluid through

the Capacities Chart.

is in

should be between the two dimples on the dipstick, about Vt

below the

4.

it

Front and Rear Drive Axles

Return the lever to Park, and check the fluid level with the engine idling. The

3.

the lubricant level

.

FLUID and tighten the

superseding type

its

correct

l\^ove the gearshift lever

10.

2.

lubricant with a suction

in

filter.

the pan,

With the gearshift lever

9.

1

the drain plug from the bottom.

the area clean and install the drain plug.

plug and tighten

race the engine.

>

Remove

level surface.

plug from the rear of the transfer case (behind the

tiller

a crisscross pattern.

the dipstick tube.

level

4.

the

install:

Nm)

(25

If

and gasket must be replaced.

filter

Remove

there

the transmission.

On

Slide a pan of a least 6 pts. capacity under the case drain plug.

or screen to the valve

may be found on some models. The

reusable strainer

To

filter

dry

in

With the transfer case warmed up, park on a

3.

transmission).

Remove the pan bolts and empty out the pan. On some models, may not be much room to get at the screws at the front of the pan. to air

1

2.

installed.

3.

it

these locations

DRAIN & REFILL

burnt, serious transmission troubles,

Clean the pan with solvent and allow

differential filler plug

in either of

to drain nnost of the

probably due to overheating, should be suspected.

4.

may be

pry the pan loose. You can buy aftermarket

this operation a bit less

removed smells

fluid

one corner down

bolts, then pull

VERY CAREFULLY

drain plug kits that

»lf the

pan

the

all

sticks,

it

If

147 The rear

Fig.

fluid

level with your finger

Place a shallow pan underneath to catch the transmission fluid {about 5

2.

pints). fluid.

146 Check the transfer case

Fig.

mission

plug opening. Lubricant

in

should be checked immediately should be V2

in.

(13mm) below

at least

after-

the

filler

the rear axle should be up to the bottom of the

may be added

with a suction gun or squeeze

GENERAL INFORMATION AND MAINTENANCE 1

Park on level ground

2

Remove

3

II

Ihe

plug Irorn the dillerentlal housing cover

lillcf

lubricant ttlckles out there

and check

up

that the level Is

should be run

LOCK

in the

Fill

enough

bottom

position lor

assure proper lubrication to 4.

to the

is

ttie

II

Refill Ihe differential Install the filler

Locking

Iront

hubs

10 miles (6 km) each month

to

Iront axle.

with the proper lluid. install the plug and

tighten

to:

proper lubricant—do not

ttie

—25

-25

Nm)

•

8'/f in

.

9'/^and10'/iin— 19lt

.

9%-10

See Figures 152. 153, 154. 155 and 156

DRAIN & REFILL

The cooling system was tion that is

ing

» See Figures 149, 150 and 151

down

good

to

for year

the factory with a high quality coolant solu-

filled at

around operation and protects the system from

-20F (-29C) (-32F/36C

Canada)

in

It

is

good

years or 24,000 miles (38,500 km), whichever occurs

No

intervals are specilied lor

every year or so.

II

changing axle lubricant, but

you have driven

in dialer

it

a

is

good

idea

proper concentration

over the axle vents, change the fluid

immediately.

The hot coolant

normal operating tempera-

of

coolant

level

and the cold coolant

Park the vehicle on the level with the axles at

1.

overlilll

FRONT:

REAR:

•

with

plug and lighlen both plugs to

REAR:

not. carefully insert a linger

ol Ihe hole

at least

1

8

1-41

is

two

lull

Ireez-

calendar

provided that the

maintained

should be

level

first,

for

the

at

should be

at

FULL HOT mark on

the

the expansion tank

FULL COLD mark on

the lank.

Do

not remove the radiator cap to check the coolant level.

ture.

tial

2.

Place a pan of

3.

Remove

4.

If

the

at least

filler

6 pints capacity under the

housing.

differential

FLUID RECOIVIIVIENDATIONS

plug.

you have a drain plug, remove

it.

If

not, unbolt

and remove the

differen-

On 1988-95 models,

the coolant mixture in

Chevy/GMC

trucks

is

50/50 eth-

cover. install the drain plug, or differential cover. LJse a

5.

new gasket

ylene glycol and water tor year round use. Use a good quality anti-freeze with if

the differ-

water ential

cover has been removed,

6.

Install the drain

plug and tighten

it

so

it

«/ill

not leak.

pump

lubricants, rust inhibitors

and other corrosion

acid neutralizers.

Do

not over-

On 1996-98 models. Use Do good idea

to replace Ihe

gasket at this time.

Fig. Fig.

149 Using a wire brush, clean the

bolts

Fig.

and edges

of the differential

cover

152 The system should be pressure-

tested once a year

150 After removing the

fully pry the

not mix any other type of coolant with the

patible

bottom

of the

and may cause damage

Fig.

to the

coolant and water. they are incom-

cooling system.

bolts, care-

cover

off

and

153 Remove any debris from the

Fig.

151 After the

oii

has drained, remove

the differential cover

drain the fluid

ator's cooling fins

DEX-COOL' DEX-COOL' as

a 50/50 mixture of

tighten.

'^It is usuaily a

inhibitors along with

radi-

Fig.

154 Coolant condition can be checked

with an inexpensive tester

1-42

GENERAL INFORMATION AND MAINTENANCE GASKET

GENERAL INFORMATION AND MAINTENANCE Ihe dirt Irom

around the covet

master cylinder

Clean

Clean

Be sure

2

Be sure

3.

Carelully pry Ihe clip Irom Ihe lop ot Ihe master cylinder to release the

3.

Carelully

On some

4

The

cover.

The

4

all ol

Itiat ttie

lluid level

11

is

just pull

and

% in

marl