oil leak not from rear main seal

[evaddave]

My buddy is trying to get the Jeep ready to go to TDS next weekend. He is having trouble stopping the oil leaking from the rear of the engine near the cover oon the front of the transmission. We changed the rear main seal and oil pan gasket and only managed to slow the leak down a little.
What else could be causing the leak at that spot?
We are running out of time and really want to go to Truckhaven and play.
Any help?
Its a 1980 CJ7 with a 304.

 

[TerryMason]

Were you able to figure out where the leak was?

 

[SteelHeadz]

If the leak appears to be coming higher from the trans. bell housing on the engine, check the valve cover gasket for seapage or check the torque on the bolts. also check the rear of the intake manifold gasket.

 

[jbcj5]

Had the same problem, turned out the oil presure sending unit was weeping when motor was running and the oil dripped down the block on top of the starter and worked its way down to the inspection cover and dripped on the ground and also made us think it was a rear main seal leak.

 

[SteelHeadz]

Had the same problem, turned out the oil presure sending unit was weeping when motor was running and the oil dripped down the block on top of the starter and worked its way down to the inspection cover and dripped on the ground and also made us think it was a rear main seal leak.

The Oil pressure sending unit on a 304 and 360 is on the side of the block passenger side just above the Oil filter in the front area.

 

[jbcj5]

The Oil pressure sending unit on a 304 and 360 is on the side of the block passenger side just above the Oil filter in the front area.

My bad, I'm a little 304-360 challenged, have a 258, need to read the whole thread before spouting off next time.

 

[evaddave]

haven't fixed the leak yet but did manage to solve another problem and learn a bit about the inner workings of the lifters. It was backfiring out the carb and it turned out to be a severely worn lifter on #7. I know it most likely has a bunch of worn lifters and the cam is probably flat but like I said in my original posting we are just trying to get to Desert Safari.
Still looking for ideas as to what else can cause a good size leak on the back of the motor.

 

[ljrubitm]

Not to put you down, but are you sure you did not scrach or cut the seal when you installed it? Just a thought.

 

[T-rav]

Did you clean the surface where the new seal was going. If theres any residue from the old gasket the new one wont seal.

 

[evaddave]

Okay we're back and had a great time. We did give our mother earth some of her oil back but not too much. Oil does come from the desert, right?
Anyways back to the seal. I'll admit that I had to change that seal twice. Apparently when I looked at the way the lip on the upper half of the two piece seal went(forward of coarse) I inadvertently rotated or flipped the seal before installing into the block. It leaked way worse than it originally did and I replaced it again not believing what I did. The surfaces are clean and looked good. Oil pan seals and gaskets were in tact and right where they should be. The leak is now slower than before doing the job but still a pain in the ace.

Now that we are back and don't need the Jeep until Memorial day weekend I suggested he do a cam, lifters and valve springs. Is there a cam seal or other seal in the rear of the block?

Would taking the inspection cover off the transmission give me any insight? It wouldn't be a straight line of sight thing. I could maybe stick a dental mirror up in there but would I be able to see any higher than the crank?

I've had the intake off and on again and used a new gasket (metal) and RTV Black on ends and around the water ports. The block and intake surfaces were clean and in good shape. It just drips down between the trans and engine

 

[ljrubitm]

So your saying it still leaks? Go get yourself some engine cleaner, clean the whole engine and around the Trans. Run the engine for a while then look under the jeep . See if that helps to locate the leak.

 

[buckaroo kid]

Its more an likely going to be your valve cover gasket leaking

 

[SteelHeadz]

Okay we're back and had a great time. We did give our mother earth some of her oil back but not too much. Oil does come from the desert, right?
Anyways back to the seal. I'll admit that I had to change that seal twice. Apparently when I looked at the way the lip on the upper half of the two piece seal went(forward of coarse) I inadvertently rotated or flipped the seal before installing into the block. It leaked way worse than it originally did and I replaced it again not believing what I did. The surfaces are clean and looked good. Oil pan seals and gaskets were in tact and right where they should be. The leak is now slower than before doing the job but still a pain in the ace.

Now that we are back and don't need the Jeep until Memorial day weekend I suggested he do a cam, lifters and valve springs. Is there a cam seal or other seal in the rear of the block?

Would taking the inspection cover off the transmission give me any insight? It wouldn't be a straight line of sight thing. I could maybe stick a dental mirror up in there but would I be able to see any higher than the crank?

I've had the intake off and on again and used a new gasket (metal) and RTV Black on ends and around the water ports. The block and intake surfaces were clean and in good shape. It just drips down between the trans and engine

There is a Cam Plug on the back of the block. also, there is a oil galley plug on the rear behind the flywheel.. That intake seal shouldn't leak at all if it's properly done..

 

[evaddave]

Its definately NOT leaking from the intake or the valve cover gasket. These plugs you speak of, are they usually changed at overhaul time or just when they leak?

 

[SteelHeadz]

Its definately NOT leaking from the intake or the valve cover gasket. These plugs you speak of, are they usually changed at overhaul time or just when they leak?

The plugs are removed during a major overhaul for cleaning all the oil galleys in the block from honing or other machine work that may leave abrasive trash. the plug is a screwed into the block and can be re-sealed after service.

 

[evaddave]

okay thanks for all the help guys. I'll pass it on.