I am afraid that I know the answer to the question but I will ask anyway. I have a 1999 DI with 104k miles on it. I have had some oil leaking, not much, that accumulates at the bottom of the front of the bell housing. It seems to be coming from the passenger side of the bell housing along the starter mount. I just don't want to believe that it is the rear main. We left town last week and parked the truck in the driveway on a slight incline. When we got back after a week, there was a spot under the bell housing about the size of a large pancake. There was also a noticeable leak off of the bottom of the bell housing, apparently coming from down the passenger side of the bell housing or above the starter and running dowm the side, opposite side of the drip hole in the bell housing. I am baffeled, I can't tell where it is coming from. When I remove the access cover on the bottom of the bell housing everything seems dry inside. While sitting, and not running, is there anywhere where oil would be sufficient to drip to the extent described?

If it is the rear main, does the tranny need to come out or can it just be unbolted, along with the transfer case, unbolted from the rear prop shaft and shifted back to allow access to replace the seal? How big of a job is it to do? Anything else to do while I am in there? Thanks, here's to hoping it is something simple. Other than the described leak, the engine and tranny are virtually dry. Phil

 

Ok, I won't say what you don't want to hear, but did you ever take a small inspection mirror and look at the back of your head? (engine)

Mines leaking at the front of the valve cover, you can't hardly see it because the oil is clean until it gets down the block a ways.

I think your bell housing would be oily inside if it was the rear main.

Hows that?

luck,greg

 

Yeah, I'd be looking everywhere else very carefully before diving in the the rear main seal, especially since you say it's dry in the flywheel and bell housings.

If it does turn out to be the rear main, there are two schools of thought.
1. It's most likely the cross seals (called they because they look like a cross) on the sides of the rear main bearing cap, which can be replaced without separating the the engine/gearbox.
2. If you replace the cross seals it will disturb the rear main seal (it's held in place by the bearing cap) and you'll need to replace it anyway.

I lean towards #2, but others claim good success with just #1.
For #2 you can slide the gearbox back as far as you need to gain access to removing the flywheel and replacing the seal.

 

Well after looking at it for the last 6 months, I pulled the front access cover off of the bell housing. Not the round inspection cover on the bottom, but he crescent shaped cover on the front of the bell housing. Had about 8 8 mm bolts and 2 12 mm bolts, not sure on the 12 mm bolt size, I just put the one on that fit and couldn't read the small number on the craftsmand socket..... Dry as a bone inside, the only oil residue was that which slipped in from the top and ran down the inside of the cover plate. Turns out the oil is coming from the front of the right side head gasket, dang. The oil runs down the block, and then along the oil pan, to the fron of the transmission, bell housing. From there, it spreads out along the top of the bell housing front cover. It isn't too bad, I have lost about 1/2 quart over the last 2000 miles, but I have been cleaning it off with simple green on a weekly basis, the oil drips on the driveway are killing me.

Other than the oil leak, no ill effects from the head gasket issue, temp is consistently just below the midline on the gauge. I suspect it is just a matter of time.

I did note that it looks like I also have a leak from the front transfer case input seal. Does that seal require the t/c be removed to replace? i replaced the rear seal a few months ago, not too bad a fix, just a pita.

Thanks

Phil
1999 DI
2001 DII