M35A2 Deuce- Small Oil leak when sitting through Flywheel !

[saddamsnightmare]

July 8th, 2008.

Gentlemen:

I'm just looking for thoughts on source of small leak of engine oil through flywheel drain hole when stopped (shut down)..... She doesn't do it every time, when she does it will very from half dollar size spot to pringle's can lid diameter.......
The dripping's driving me nuts, about as bad as a Model "T", but she normally doesn't go through a quart or at most two, of Rotella in the usual 1000 miles run, so the leak can't be hairy bad. Will Wagner and I have been discussing possible sources, and I think a Texas heavy truck mechanic instituted the problem by overfilling the lube system when changing the lube oil filter gaskets and replacing the rear Air Compresser crankcase head gasket.... The puppy didn't believe me when I said don't add oil as it takes 6 hours to drain back to the crankcase and so the dipstick reading will be off..... SLOW LEARNER!!!!
I figure there's gotta be a worn seal or gasket where the crankshaft passes out of the rear of the crankcase, and I know I'm gonna be out for at least the seal and a new crankcase oil pan gasket, but there's gotta be a solution short of a complete tear down.
The truck has about 24,800 miles since rebuild in 1990, and most of what I've been fixing is the usual gasket and hose failures due to age.... Oh, yes, she's a normally aspirated multifuel, used to be Bull Dog Mack 13's first serious ride before last October (2007), gets about 12 to15+ miles run daily, below 40 MPH (actually averages about 22-28 MPH),
so she's in normal Tactical Truck running speeds, with much more care then the Army ever gave her!

Throw your hat(s) into the ring, this oughta be a good instructional piece, and thanks for the insights.

Sincerely,

Kyle F. McGrogan

1971 Kaiser Jeep M35A2 Wo/W "Saddam's Nightmare" Desert Storm and Vietnam Veteran Deuce
1968 Johnson Corp M105A2 Trailer
1967 Hercules MEP023A gasoline generator set
1963 Swiss Army Cargo Unimog S404.114 MB NATO green

 

[renovate7]

I'm sure you already have but make double sure it's actually coming out the drain hole. Stick your finger in it and see if it's wet inside. The oil can be coming down the side of the engine as a thin film, not big enough to notice, and collecting there when stopped. I've had two different leaks that I thought were rear main seal leaks coming thru that hole and both were forward and higher. Thats the lowest point so anything leaking is going to end up there. My leaks were valve cover and return line between the turbo and block.

 

[devilman96]

If it IS comming out of the bell housing its rear main time... Not a heap of fun but not so bad ether. Consider your options as far as clutch, seals, etc while your doing it.

 

[OPCOM]

I thought my deuce was leaking because of as little bit of oil there, but then discovered it's the normal operation of the undercairriage anti-rust system that comes stock on most deuces.

 

[SasquatchSanta]

I thought that was the automated floor lubber system.

I guess it could double as both

 

[m-35tom]

also note that the rear main has nothing to do with pan gasket.

 

[BKubu]

Smell the leakage to determine if it is gear lube or engine oil (they have distinctly different smells).

 

[BEASTMASTER]

if it don't leak, it ain't a truck

 

[BEASTMASTER]

if it don't leak, it ain't a truck

 

[BEASTMASTER]

oops!!

 

[FSBruva]

To quote Kenny (Recovry4x4):

"There's a reason they're called 'road oilers!"

If 's really bothering you, you might try one of those "seal remedy" thing to make the rubber more.... better. Keep in mind that according to the military, losing 1 quart of oil per 61 miles of operation is acceptable. That includes past the turbo seals, the rear main and anywhere else oil might exit the engine.

As a word of warning before you drop the transmission -
I was getting a drip similar to the one you describe. So, I replaced my rear main seal, and my pilot bushing. With a brand new rear main seal, the drip was reduced, but still does it on warm days or when run hard/hot. Just something to keep in mind.

Matt

 

[chuck500cc]

Mine leaves drops about the size of a baseball when I park it at night. Problem is that I am getting some "clutch hop" now.

Chuck XD Fan