Engine oil in bellhousing?
 

Trying to figure out where it's coming from.

Main seal seemed OK, but I'm replacing it anyway. The old flywheel had a fairly deep scoremark from seal wear (27 years on it) but it didn't LOOK likethe oil was coming from there, either.
Funny thing is, a couple of tension bolt heads are wet from oil... but none of them pass thru oil channels - - they only transit the water jacket area, far as I'm aware.
Only places I can think of being possible are:
Main seal
Base of the stationary gear
Possible spilled oil from filter change that seeped in and got trapped.
Anyone else ever seen oil in the bellhousing that had another source?
Puzzle!

the FD's love to leak from the stationary gear O-Ring.

Good to know. I will doulbe-check in that area, but it seemed tight. I backed up the o-ring with silicone on the flange at rebuild time, and haven't previously had issues there.

It's not a ton of oil. But it should be dry in there.

Is it on the back side of the flywheel? As if to be slung from the back of the engine? or is it mostly on the bottom?

Sure its motor oil? Could be gear oil but that defiantly has a distinct smell. Just tossing it out there.

Could be from the oil pan. There is a small notch in the bell housing on the bottom (I assume to let any liquids drain) This could collect oil from the oil pan; however the oil gathered here wouldn't get on the back of the flywheel but could be picked up and slung around in the bell housing.



Could have a crack in the rear iron. :O But I think that mostly affects FC engines.

The flywheel itself seemed oil free, front and back, as did much of the rear face of the iron except at the bottom, and on a couple tension-bolt heads to the lower right (looking forward).

Thin coating of black burnt-oil residue all the way around the inside the bell housing itself, so clearly it gets 'flung' by the flywheel. Definitely not gear oil based on lack of smell.

I rechecked the interface between the stationary gear and the rear housing, and it seemed dry all the way around. Retorqued the bolts there, and checked all the tension bolts but none had worked loose or broken (which would be a water issue rather than an oil issue, generally), replaced the e-shaft seal and as I'm using a brand-new counterweight the shaft seal should now be 100% tight.

Oil pan seal would seem too low in comparison, but I suppose it could wick upwards.

No obvious signs of an iron crack - and as mine was painted at last build, it should be easy to see if oil was coming through from under the paint.

I guess I'll just have to see if it recurs. Transmission went back in last night.

I'll post some pix of the uncleaned iron when time presents.

Excessive grease on input shaft from last clutch/gearbox install?

I'd also guess the stat gear o-ring as well, maybe some of the sealant released and created a small leak. If the rear main seal is good there shouldn't be oil getting through there - what a conundrum!

Definitely wasn't install grease - consistency of engine oil.

Maybe three drops dripped out when I separated the trans from the engine, in all respects looked, smelled, and felt like 20w50. the rest was just trace oil stuck to surfaces.

I sure hope it's not the o-ring, as I really don't cherish the idea of removing and remounting the trans again. Took me and two friends a couple hours of crawling around under the car on a roasting hot day to get proper alignment.