PS Magazine Issue 045 1956 Series [45 ed.]

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WEDDING NOTICES t."

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PS MAGAZINE

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"tin" is happy to a nnounce the macriage today of one of its veh icles to G I driver. Maid of H onor is Connie Roo d, who first introduced the couple at a

pool.

~,r"W~ Next time someone comes up to you and asks- ""Whose vehicle is that you're driving?" don ' t beat around the bu sh . Come right out and tell him it' s

yours-AR 750·5 (23 Jan 5.3) says so.

Para 9 of this AR makes operators and crew chiefs personally r es pon sible for their vehicl es; it makes squad , section and platoon leaders respo nsibl e for the s upe rvis ion of vehicles in their command ; and it makes unit and organization co mmamlers r es pon sibl e for seeing Ihat the vehicles in their command are prope rly cared for ami used.

t, the main respon s ibilil y ~ with);.ou - thc rlriver or crew

chief. ~o , as long a s you ~ re the Ofte'_resp§T1 s ible for everything that , "appcn s 10 thai vehicle~ you eanJu sl go ah{,811 and assume , l hat iI~ s yo urs-cvery nut boh of it . Please treal il as s uch-jusl for me-huh?

1956 s...i.s

IssUtl No. 45

Published by the Departllt,t of the Army for the inform.· tion 01 'lla.inltio",1 mailtenaltCe and supply personae!. Distribution is made through normal publication channels. Within limitations of availability, older issues may be obtained direct from Preventive Maintenance Agency, Raritan Arsenal, Metuchen, New Jersey.

IN THIS ISSUE FEATURE ARTfCLES M42 "Duster" Mount Track Suspension Wheels Power Timing Light 5-Ton Clutch The New UER Man-to-Man (Cartoon .Section) Your BAR Up to Par? Switch Those Fuse Holders (Engineer) Losing .Its Prime? (Engineer) Coat Your Can

2 8 10 14 21 38 42 44 48

DEPARTMENTS Half-Mast Connie Rodd Armament Engineers Publications Contributions Connie Briefs

30 34 38 42 4S 47 49

PS Magazine wants your ideas and contributions, and is glad to answer your questions. Just write to: Sit HaH·Mast, PS Malazine, Raritan ArseRal, Metuchen, New Jersey. Names and addresses are kept in confidence. Tlte ,rimng ef PS Magazine, ~e PREVENTIVE MAINTENANCE MONTHLY, is ap~rned by tile Director, Burtallef the Budget (4 Alii. 53), nd is llistri· ~uted as loins: DISTRIBUTION: ACTIVE ARMY: Gen Staff, OA (1) ext.,t DCSPER (2); '"$S, DA(l); hc SVt, OA (5) except COrENGR (15), CorORD (275); AdlliR & Tee SIC Bd (5); Hq CONARC (10); OS Maj COlld (5); OS Base Ce.d (3); MOW (5); hies (SOl; Corps (3); Div (2) exce,t n~ Oil (1DD), Tng Div(50); Brig (3); RegtlGp (3l; Bn (5); Co (18) exce,t CIlIC. (8L Med Co (8), QM Ce(S); Ft & Cp (6); Gen & Br SVt Scll (5) nee,. EDgr Seh (lOD), Ord Sch (25); USMA (25); Joint Sch (5); Specialist Sd (5); PMST (3) ntept PMST Ord ROTC Units (25); GeD napets (5); SIP Sec, Ge. Oepets (5); DejlClts (5); AN (5); RTC (100); Trans Teminal Clflld (3l; AlII' hrlliaal (3l; OS Sup AgeAcies (2); PG (5l; Arsenals (25); DB (25); CruitMai. Sta(3); Div hgr(2); Oist Eng:r (20), NG; State AG Special List. USAR: Mil Dist Special list, FIr explanatillll II abbreviations IIsed seeSR 32G-50·1.

That's right. You ' ll never do mu ch fancy ridin' and shootin ' if you don't know your .mount-as any of you broncbusters know. So, gather round and get the right cadence for running that ~4El mOunt on the M42 " Duster "-your (win 40mm antiaircraft job. 'Course, d o the regu lar automotive [-!,~~~'-k~ checks eve n before climbi ng up on the gu n mount. Put fuel se lenor va lve o n BOTH ON, Go over your engi ne, transmission, Li 'l Joe, batteries and air cleaners. When a ll regular before-operation maintenance is taken care of, you're set to hop into the 'm o unt and get ready to unlimber {h ose {w in 40's in power operation. D o it this way , by these num bers, and only this way. It'll save life and limbs and statements of charges, Good idea to

~~~=!!~~aiM~i~~ ..

-

memorize the steps shown in the fo1lowing drawings:

2. Be sure you'reporked on level

I't'

That's right. You'll ncve r do much fancy ridin' and shootin' if you don 't know your m o unt-as any of you broncbusters know. So, gather round and get the right cadence for running that ¥ 4E 1 mount on the M42 "D uster"-your twin 4 0mOl antiaircraft job. 'Course, do the regular automotive [:~~;~;2:-:J.-~ checks even before climbing up on the gun mount. Pur fuel sclenor va lve on BOTH ON. Go over your engine, transmission, Li 'l Joe, bancries and air cleaners. \'\fhen all regular before-operarion maintenance is taken care of, you're se t to hop into the mount and get ready to unlimber those twin 40 's in power operation. Do it this way, by these numbers, a nd only this way . It' ll save life and limbs and statements of charges. Good idea to

~~lC_iil~~. - ~mori ze the steps shown in the fol!!!I

lowing: drawings:

2. Be sure you're parked on level

7. Check oil level in azimuth and elevationoil-gears. If side inspection window isn't ot leost half full, pour oil in .. . real slow, like molasses in the deep freeze.

3

7. (heck oil level in azimuth and elevotionoil-gears. If side inspection window isn't at least holf full, pour oil in ... reol slow, like molasses in the deep freeze.

3

9. Inslall

10. Manually pull sight light slowly to le't to see if there's e~ough play in sight light cable. (On (J new vehicle you may hove to loosen (I couple of I to let Ollt (oble before traversing.)

time.

Now here's where you've gO[ to be careful, because that swiech lever has caused Ordnance more work chan a thousand gremlins. Some guys have the habit of disengaging that switch lever, then engaging her again when the mount's still moving. Naturally, this grinds out the slewing clutches in the two oil gcars real sudden-like-and your vehicle goes back to Ordnance. When you're firing, keep the switch lever engaged all the time. Never, never throw her in gear when the mount's moving,

or when oil gears are not completely stopped. 4

If you've done everything right so far, flip on the rate switch and she's ready to roll. Be sure the rate switch is the last thing you turn on. If it's on and you hit the control handles as you sit down in your seat or as you move around, the mount'll be whipped around like a dart in a wind storm.

For manual operation, you've got only five steps:

3. Put on the ring sights, making sure the wing-nuts are tight.

elevation-locks, and she's ready for manual operation.

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You've also got to keep your preventive maintenance on the ball in other ways with the "Duster's" mount. Keep the mount free of dirt and moisture. Remembe'r that the gun mount, recoil cylinders, and equilibrators need exer-

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.

By setting the speed knobs

at IOO·MPH

In ROtating the direction of flight knob manually in ,both positions

Don't tamper with the computing sight or try to open it for service or lubrication. She's [00 delicate for that. Just keep her exercised. 5

SCOTCH THAT SCORCH! "

Been doing any trailer towing with your M42 l' , "J twin·40 ? Then you know how your towed load gets stuck in the Jine-o-fi re of those main engine exhausts. Right? WeJl, the idea people have been cooking up a

twin deflectors which shoot the scorchy lIJl instead of back. To get yo ur "D uster" fixed up with the tors, see your Ordnance support unit. Kit, modification, Ord Stock No. 5702092, containing two deflectors, two U·bolts and two clamps. Besides the kit, a few other items ore needed for the job. These ore to be had through regula r supply ,honnels, 4 Nuts, s/16 18NC-2, O,d Stock No_ HOOI-4167541 ; 4 Washe~, lock, S/16 in HOOI-7023711 ; 4 Washers, ploin, '/. in HOOI -04463 63 _

They

4.

Now all y'goHo do to SKure the fs tighten the nuts on the U.bolt-moking sure you've got it well over the underskte of the deflector, so WII hold

Shove the deflector forward on the tail pipe 1'/, ilKhes, with the beveled end up and

at 0 4S-degree angle toward the renter of the vehide. 6

ENGINE WIRING JUNCTION BOX

Here's onc to watch if yo_u'rc working i?!.'"Ound the wiring circuits of your M48 tank. The generator has two coorrolling circuits -the field circuit and the generator equalizing circuit, sometimes called the paralleling citcuit. The field circuit is No. I, and the equalizing circuit is No. 478. OK-as long as these are hooked up right you've gOt no problem. These leads plug into the little three-wire plug in the centcr of your engine wiring junc-

tion box. The field circuit, No. I, is on pin

n of the plug, the equalizing circuit, No. 478, is on pin A of the plug, and pin C of the plug is blank.

BULKHEAD WIRING DISCONNECT

Now, watch this: Back at the bulkhead wiring disconnect, these circuits also come through a three-wire plug. But they use differem pins. The field circuit uses pin A and the equalizing circuit uses pin B. As long as you leave this harness alone, no harm is done. Bue sometimes you may have to make up a new harness, or replace a plug. This is quite OK, unless ehe), go ahead and connect pin A at one plug to pin A on the other. This sounds logical , but ir's nor right. H you install a lead hooked up A to A and n to B-by yimminey, you got troubles. Such as a burned-out generator and/or regulators. This is more confusin' than amusin'-but look ar the right-hand side of rhe diagram, Fig. 109 in TM 9-7012 and you' ll sec. Just follow circuirs 1 and 478 from rhe bulkhead wiring disconnect line our to rhe right, and you'll see 'em jump over. 7

Funny thing about track suspension the w.idth of the flat wear area will tell wheels. Lotta people seem to think the -indirecdy-how much of the flange'S rubber tread on the thickness has been wheel is about the worn away (Fig3). only thing that Now-if y'know needs to be watched how wide the wearfor wear. area should be when T'ain't so. Those the wheel's ready wheel metal disks for turn-in, you're set to save those have flange area bogies (and support (Fig J) that's conrollers, idlers, etc.) stanely rubbed, scraped and scoured :==::':=::::::::::::':=::::::===~ So rest your best eye on the flangeby your track cenwear chart. The first ter-guides. The three columns idenflange wears down SIX t'i fy your wheels eventually; and, if IN(H (disks). The fourth it wears toO far, the SUllE column tells yOll at wheel is shot-for what point (wear keeps. area width) the However, by WHEEL wheel should be keeping an eye on Fig 2 FLANGE this wear, and turned in. Do it then and knowing what to you save the wheel look for. you can -and a sizeable turn a worn wheel chunk of highly dein for rebuild while it's still in shape to sirable dough. Let it salvage. wear further and the The simplest way whole works goes to do this is take a down the drain. six-inch scale and You'll see this and measure the width a lot of additional of the flange wear area (Fig 2). Since dope on track and other suspension the original flange surface is rounded, items in the new revision ofTBOrd 562.

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8

USED AS

G163·1621440

Support roller

M18 Carriage (76-mm gun)

1fs in.

G200·1636637

Support roller

Ml9 AIV, M71 AIV, M19Al (orriog', M37 Carriage, M41 Corriage, M42 (SP), Gun (twin 40·mm gun), M44 Howitzer (SP) , T98E1 Howitzer (SP) , M2.fTonk, M41 Tonk, M8E2 Tractor Icargo)

]1/. in.

•

ON THESE VEHICLES

MAX. WIDTH Of WEAR SURfACE

DISK lORD STO(K NO.1

Gl04·1631849

Support roller

T97 Gun (SP) , nOB Howitzer, M4 Tanks, M26 Tonk, M46 Tonk, M47 Tonk, M48 Tonk, T43 Tonk

lS/16

in.

G104·1631861

Rear idler

M40 (arriage, M4 Tonk

19132

in.

Gl04·1631844

Roodwheel

M40 (crrioge, M4 Tonk

l Va in.

G211·6S76489

Roodwheel

M19' AIV, M71 MV, T8E4 Bulldozer, M19A·l Corriage, M3T Corriage, M41 (arriage,

11 1/16 in.

M42 GlIn (twin 40-mm gunl. M44 Howitzer (SP), 198H Howitzer (SP),

M24 Tonk, M41 Tonk" M8E2 Troctor (cargo) G163 ·1621441

Roodwheel

MIa Carriage, M39 Vehide (utility)

113/32 in.

G216·7013976

Rl)odwheel

197 Gun (SP), nOB Howitzer, M26 Tonk, M46 Tonk, M47 Tank. M48 Tonk, T43 Tonk

11/. in.

new Power Timing Light, FSN 6625·378·2073 that's showing up in the second echelon toolsets. If you're used to the old neon timing lights (Ord Stock No 41-L-1440) or the pistol-shaped commercial timing lights, you may get quite a surprise when you first meet the new one. Relax, you don't have to take that steel box down into the engine room with you. The lamp itself isn't any larger than the old neon type and isn't as big as the commercial style. The box you can leave on the fender or even on a work stand. But you'll find that this new light is many times brighter than the neon lights were. Also, since the principal source of power is the vehicle battery, it has'no tendency to cause the engine to miss. In the box is a selector switch which has positions for OFF, 24 volts, 12 volts and 6 volts, in that order. You set it for whichever voltage you are using, acto the vehicle and according to whether you're using one or both bat(You see, you can use only the under-hood battery on the M38Al, or one of the M135/M211 batteries if you choose.)

IT WORKS LIKE THIS-

Two battery leads, a high tension lead, and c careful that YOllr(cygin!t ()5:Sif't'r yit a~ay and speed up ove: figttfe. W:~t!:t1; going downhill. you should pick a"ng-hr gear range and use rour.., ~ice1;r;,tke to keep that engine.,. from evvingw'..up over 2800-

DEPARTMEMT

OF

THE

AlMY

TECHMleAl

'llLETIM

If-

RPM:"".~ ~...L';; Yp':! tan

cur

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out a little q ~ur tachometer to wam .li abou this;,' Like it shows v-, ,,~-I !~(he ~£'. th,~culQ.,u~,;ln be a ?anger m wuh:t~b:i...;se.~sted agamst the 2.. r , i).,.~ ur,.-ach and pointed

paste-lJp and pur i

:h~~h~~s alc .

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MWO::Ofd G744·W15 and MWO Ord G744·W16

~~ ~~6frmuch you can do about

th~~~O' ~except get yOut truck , baC}Ct >Orcln:lnce. They're higher ~~rr jO~7 }j~ they're classified as \; .-. clone right away

puc in a better seal that'll keep lube from getting into your clutch housing and tubing up the works. Once that oil and grease get on your clutch, the old boy burns and burns and burns.

That's it, except treating that clutch 15 (13 Sept 54) right while driving. Once you get these Mar 55) and TB's and MWO's carried out (and Cliang~~~lrre:5.f) ~lls Ordnance to you're nOt doing some fool thing like put . ~ t,s ~ 9n your clutch- riding the clutch) and your clutch is rd s() \!:~e ;tts on the lever still bugging up. there's only one thing won ~~~, nd foul up the in- you can do-deadline the thing and get nards 0; a UER (Form 468) off soonest. \Vhen ~\V "~16 (5 Nov 54) that's done, you can sit back-you've and i~ 1\ (23 Mar--,-5'5 '"'"a n ""-done your work and it's now up ro Change 2 (1-3 Feb ,or{~lls 6rdl1jloce/(6 .r~Ordnance. 16

TRICKY THERMOSTATS "Deceiving" is the word for those Vernatherm thermostats you'll find mounted o n your G749 2 Yz-con trucks. Unless (hese babies are checked out right, they' ll give you the idea that they' re shot and read y for the junk pile. This Vernatherm is a solid expansion type control that is not adjustable. Sure, you'll find an adjusting screw on it, but if you'll Dorice this screw is soldered on-ie's only used for an inidal adjustment at the factory. Then again the adjustment range for this thermostat is only about twO or three degrees. So. just the way the thermostat comes to you is the way you're suppo:cd to usc it.

Another characteristic about this thermostat-it opens in the opposite way from the other type thermostats-in other words, it opens against water pressurc. The installation of this control is important, so follow the installation instructions to the letter. Now, here's how to check out thesc thermostats. If you don 't do it (he right way . you'll get the idea that your thermostat is on the bum whether it really is o r n Ot .

Toke. a container, oHeosf 1~~~~ on. gallon in in 1he wooer so irs pboot threeqtloll.,•• , I'" ~'

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10 FJ I G-W2 , C211 .... Ml. Ma, P'Ofldl .... IIt' I" ~~;'J IO pr ••• nt .ceO .01'110,,01 port. , f :J.4!J.WI fuze Kit" MJi, Inol'lI "OP po,.1 oll",prOWflidU iC/l ' Dff55 &\ ·W"14 M4 1 .1ICIM4 IAII,,,kl.M42Iwln40"'''', 1".UI .. QOu. " .... ,Ide 01 ~~lcll &2i2·W2J M41T1"_, R.pllClc .... marKI' ...

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