I'm asking here b/c there are some smart fewlz here.

How the heck is oil getting into the bellhousing?

I took off the flywheel today and noticed that the inside of the bellhousing is coated w/ oil. The backside and front of the flywheel are dry. The areas in red had thick oily gunk on it.

Can oil only enter the bellhousing through the rear main seal? The mating surface of the tranny and block look clean, so I don't suspect it leaked from up above by way of leaky cam seals.

Can oil from oil pan leak somehow work its way upwards? I know my oil pan is leaking like a mothertrucker. The flywheel cover had oil both on the outside and inside.

Rear main seal looks fine. Even the dowel on the engine side had oil IN IT.

 

My money is on the rear main seal

 

input shaft seal? can you tell if its transmission fluid or engine oil for sure?

 

obviously one of the seals. whether the engine or transmission shafts depends on the oil.

sadly the rear seal on mine is going out

 

I can't tell. It looks like sludge. Smell is indistinct.

 

"indistinct" sounds like engine oil, though the tranny side does seem dirtier. Unless Honda uses something different (like they do with all their other fluids) gear oil smells pretty much like a dead whale, beached upon a mountain of sulfur from an ocean comprised entirely of unprocessed sewage, burst open from the internal pressure of decomposition over a week of 95°F days.

Is it possible that this fluid has seeped into the bellhousing from outside, possibly by riding the clucth fork past the boot?

 

Honda MTF is dino oil with some additives. I've had my share of leaky honda oil pans and the bell housing has never looked like that. The only fluid i could see getting past the clutch fork is clutch fluid. You dont have a leaky slave, correct? I would have to guess it's the input shaft seal then the rear main seal second.

 

Could be the throwout bearing gave up and tossed its cookies.... that combined with clutch dust can make a mess. Also confirm that the slave cylinder isn't leaking into that boot and then into trans.

It doesn't look like a rear main seal to me, just because its so clean against motor, that side spray would just be something sneaking onto flywheel and spraying.

ALSO.. check that HG on that side isn't a slow leak culprit... or the distributor isn't leaking it down, then into crack between motor/trans.

 

This is going to sound completely dumb, but if the INPUT SHAFT SEAL were leaking, where about the input shaft would it leak from?

Would it be the part in yellow I circled? I don't see any fluid around there whatsoever. The area behind the yellow all appears to be casted as 1 piece w/ the bellhousing.

 

kenzo, Yes. The yellow circle is where it would leak if it's the input shaft seal. I'm out of ideas, good luck.

 

The oil could have been flung off when the shaft spins, and then dried up around the seal before you removed the trans