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 general 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 from that angle.
Check out the engine trouble shooting 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’s 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 pickup 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!

What's in a name?  Jeep, who knows where that came from?

What’s in a name? Jeep, who knows where that came from?

So I’m driving around in my 1942 Ford GPW “Jeep” and it occurred to me…what the heck does “jeep” mean?  Where did it come from?  Do we even know? Well, I think the best answer is maybe…
 gpflyncls2
There’s a book by Paul Dickson, “War Slang” that says the jeep is “1, a small, low, khaki-colored car in general use in the Army. 2, a rookie; a recruit.OR you could go with his quote from another source, San Francisco Call-Bulletin, November 22, 1941 ” Do you know why those swift little army cars are called ‘jeeps’? It’s Model G-P produced by that automobile manufacturer–and G-P easily becomes ‘jeep’.” In 1941 Ford was producing a vehicle for the Army that was a model GP.

The unfortunate thing is that the War Slang book does not mention the jeep term being used during WWI or the inter-war period.  The book is available at Amazon for those that might be interested – War Slang: American Fighting Words and Phrases Since the Civil War, Second Edition.

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I like to keep my WW2 jeep in tune.  Here is the right way to do it!

trouble1

As pictured above you should start with: Sparkplugs, Battery/Ignition Cables, Distributor, Ignition Timing, Valve Clearance, Carburetor. It’s important to work through the steps and systems to ensure that you locate the source of the problem.

Source: OS 9-72 vol 1, April, 1945 and Willys Mechanics Manual, 1948. For more: http://www.42fordgpw.com/trouble/