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What parts do I need to purchase to work on my WW2 jeep transmission??

What parts do I need to purchase to work on my WW2 jeep transmission??

This is a question you will be able to answer only after you have torn down your transmission, cleaned and inspected the parts.  However, Richard Grace suggests, “the minimum parts replacement would have to be a Small Parts Kit which includes main drive gear rollers, thrust washers, synchronizer dogs and springs. One other almost necessity is mainline bearings.” 

Of course, you will want a new clutch disk and throw-out bearing (you might consider a new pressure plate as well).  So for a minimum investment (perhaps for less than $100, not including clutch disk and pressure plate), you could have a rebuilt transmission ready to install in your jeep.  Anyway a lot less than a so-called rebuilt transmission from a vendor and you will have the satisfaction of knowing you did it yourself.  You will need to add to your costs any defective or out of tolerance parts that you find during the cleaning and inspection process.

For much more about the WW2 jeep transmission, T-84J, check out my book – Trouble Shooting And Rebuilding The T-84J. This book, written by me, will take you through the process step by step–with lots of pictures!

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Backlash! I'm not talking about someone getting back at you for something you did or didn't do. No, I'm talking about your teeth. Well, your T-84's teeth on the gears, that is.

Backlash! I’m not talking about someone getting back at you for something you did or didn’t do. No, I’m talking about your teeth. Well, your T-84’s teeth on the gears, that is.

BACKLASH – Play between teeth of two gears which are in mesh (or engaged).
Check out 42FordGPW.com for more about WW2 jeeps and related information.
Are you rattled by your jeep?

Are you rattled by your jeep?

[1] A rattling sound, apparently originating in the clutch, may be caused if the clutch-pedal pull-back spring is disconnected. Connect the spring, and check to see if the rattling is eliminated.

[2] If rattling continues it may due to weak pressure-plate retracting springs or excessive clearance between driving lugs and cover. The clutch assembly must be replaced.

Other trouble shooting information and tips can be found in the following two volumes:

Automotive Trouble Shooting For World War Two Wheeled Vehicles, Volume 1 is a useful manual for anyone. Do you know what to do when the cranking motor will not crank the engine? Engine fails to start? No spark? Misfiring at high speeds or under full load? Problems with your battery or battery cables? Do you know how to adjust your breaker points? Inspect the coil? Do you know how to polarize the generator? Use a jump wire to test your main light switch? Adjust your headlights? Trouble shoot your carburetor or fuel pump? All these and much more are covered. Put a copy in your truck for those little roadside emergencies! Originally produced by the US Gov’t, Ordnance School, Aberdeen Proving Ground, August, 1945. Edited by Robert Notman.

Automotive Trouble Shooting For World War Two Wheeled Vehicles, Volume 2, is a useful manual for anyone and it takes off where volume one ended! Learn about the engine oil system. Do you know what to look for when rebuilding a block? Problems with valves? Find out how to trouble shoot and adjust the valves for wheeled vehicles. Problems with the clutch rattling? Check this manual out! Worried about your transmission or transfer case making noises? Check out the trouble shooting section. Any noises coming from your propeller shafts, universal joints or axles? Its discussed here. Trouble shooting the wheels, hubs, and rims? Chassis. Steering. Do you have brake problems, including Hydrovac brakes? Its all here and much more. Put a copy in your WW2 truck for those little roadside emergencies! Originally produced by the US Gov’t, Ordnance School, Aberdeen Proving Ground, August, 1945. Edited by Robert Notman.

Well, yesterday I was telling you not to blame the carb..but sometimes it really is the fault of the carb..or the person that put it back together.

Well, yesterday I was telling you not to blame the carb..but sometimes it really is the fault of the carb..or the person that put it back together.

 Here’s a letter that Half-Mast received from the field…
Dear Half-Mast,
I’ve run into some trouble with carburetors on the 1/4-ton Willys’ got a batch of them to overhaul and after I’d cleaned them up and replaced all parts with new ones, they were put back on the vehicles. But they just wouldn’t idle.  I checked them all over: the idle jet was clear and all passages free of dirt and lead accumulations, the economizer was free of all foreign matter, the floats were set at the specified level, and the metering rod adjusted to the proper operating length.  I also checked for cracks in the base of the carburetor and the body, and I checked the rivet plugs.  All was in order. Can you clear up the mystery?  Another question is: What are the Welch plugs on the side of an engine block for and what’s their purpose.
T/4 M.P.A.
Dear Sergeant,
There’s a lot of conditions in the engine that could prevent it from idling properly.   But I’m gonna assume the engine idled all right before you overhauled the carburetor-and then I’m gonna suggest you check the throttle butterfly.
If you didn’t assemble the butterfly with the letter “C” facing the manifold and towards the port opening in the carburetor body at the air-adjusting screw, that ‘d be your difficulty. Because if you checked all the things you said you checked the trouble is probably improper assembly of the parts.
The Welch plugs on the side of the engine block are simply to close up the holes made by the core sand legs when the block was cast at the foundry.  And just because a lot of guys call them freeze-out plugs, don’ t think they’ll prevent cracking of a cylinder block when the water inside freezes solid -they won’t.
Do you have engine trouble of some sort? Is your first thought to blame the carburetor?

Do you have engine trouble of some sort? Is your first thought to blame the carburetor?

Despite good performance, the carburetor is often called a lot of names and blamed for almost everything that can happen to a vehicle aside from flat tire and crumpled fenders.
Many mechanics are apt to make a hasty diagnosis and say, “Maybe it is the carburetor”, and then proceed to work as if that statement was a fact instead of a wild guess.  Of course, carburetors – even the best of them – do go wrong on occasion. But blaming everything on the carburetor covers entirely too much territory.  A better plan is to dig into the actual cause first, then place the blame where it really belongs and work it from that angle.
Check out the engine troubleshooting tips on 42FordGPW.com.
Don’t always blame the carb!
I suppose the 'heart' of the jeep is its engine.

I suppose the ‘heart’ of the jeep is its engine.

Below are pictures of the jeep engine in the RAW!  Pretty sexy, huh?  Okay, all kidding aside the WW2 jeep engine was pretty amazing when you consider what all it was put thru during the war years.  Also, consider that it was basically a reworked engine from the 1930s Willys-Overland automobiles.

The engine used in the 1/4-ton 4 x 4 Truck is the 4-cylinder, L-head, gasoline-type (figs. 1, 2, and 3), equipped with a counter-balanced crankshaft. The camshaft is operated off the crankshaft through a timing chain. The oil pump and distributor operate off the camshaft.

 

frtvw

Fig. 1 – Front View

 

Type ……………………………………………………….. L-head

Numbers of cylinders ……………………………… 4

Bore and stroke ………………………………………. 3.125 x 4.375 in.

Piston displacement ………………………………… 134.2 cu in.

Compression ratio ……………………………………. 6.48 to 1

Max. brake horsepower …………………………… 54 at 4,000

Compression (lb per sq in. at 185 rpm) ……. 111

SAE horsepower ………………………………………. 15.63

Maximum torque …………………………………….. 105 ft-lb at 2,000 rpm

Firing order ……………………………………………… 1-3-4-2

 

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Fig. 2 – Left View (Driver Side)

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Fig. 3 – Right View (Passenger Side)

 

From TM 9-1803A, February 24, 1944.

The Complete WW2 Military Jeep Manual contains TM 9-1803A and other publications that should be of interest to WW2 jeep enthusiasts.

Occasionally it will be necessary to flush the oil system because of an accumulation of sludge or other foreign material.

Occasionally it will be necessary to flush the oil system because of an accumulation of sludge or other foreign material.

I like to keep my jeep clean.  Don’t you?  Here are some instructions straight out of WW2 that will help you keep clean…the jeep that is.

Drain the oil from the system after warming the engine to normal operating temperature. Be sure to use CAUTION as the oil will be HOT.
Fill the oil pan to half the indicated level with light engine oil.
Start the engine and allow it to warm up thoroughly. This will allow the light oil to clean the system. Watch the oil pressure gage, and stop the engine at the slightest sign of low oil pressure. This may be caused by a clogged strainer.
When the engine is thoroughly warmed, turn off the engine and drain the oil.
Fill to the proper level with the correct engine oil.
If the oil filter has a replaceable filter element, inspect it and replace if necessary.
Caution: These are recommendations from WW2, always consider if this practice is considered safe for you or your equipment before proceeding. If you follow these instructions I would use extreme caution and watch closely the oil pressure gauge. I would also suggest using 10w oil as my “cleaner” and I would fill it till it was at the full mark instead of half. The sump pickup in a jeep may not pick up the oil if it is only half full. I suggest always changing the oil filter when changing the oil. But I wouldn’t change the filter until after the cleaning. Again, exercise caution.

The Complete WW2 Military Jeep Manual contains many more procedures that will help you with your WW2 jeep.  If you don’t own the WW2 jeep manuals–you need them!

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