rear main seal leak after swap

[Dirtnap30]

so 2 months after completing my m52/zf trans swap I've started to develop from what seems to be a rear main seal leak. I'm beginning to get concerned because I keep hearing mixed things about wether or not I can drop the trans by itself. I've only had the car up on a lift once to diagnose the leak but I did not get a good view of the bell housing bolts to really confirm this. how should I go about this?

[Thrizzle]

Yes you can drop the trans by itself.

But first Id get a better look at the underneath. Get a light up in there and inspect around the oil filter housing, vanos line and such, see if they aren't the problem.

[scottinAZ]

another likely source of leakage is the flywheel bolts. if they are not sealed, they will leak. Mimics the look of a rear main seal without the hassle to change the seal itself.

as for dropping the trans, its easiest if you remove the sound deadening material. Top pass side bolt is nearly impossible to get with it in place, piece of cake with it removed.

[Dirtnap30]

I honestly cannot tell if its the back of the pan or the rear main. I doubt its the flywheel bolts because I used loctite and im sure with that kind of leak my clutch would be slipping. also I sealed the shit outa the pan with anerobic sealer and let it cure. only seal that wasnt replaced was the rear main :( didnt leak when it was in the previous car so I figured leave it alone.

[Jand3rson]

only seal that wasnt replaced was the rear main :( didnt leak when it was in the previous car so I figured leave it alone.

This is the same mistake I made when I first dropped my M50 in, I just totally forgot it. Sure enough, every time I drove the car, I'd have about 2-3" wide puddle of oil right under the bellhousing.

Pulled the motor back out (had some other stuff to do), and put in a new RMS, with an SKF Speedi-Sleeve on the crank/seal shaft, hasn't leaked a single molecule since.

[Dirtnap30]

should I use a sleeve even if the motor doesn't have high miles?

[scottinAZ]

should I use a sleeve even if the motor doesn't have high miles?

Yes, especially if there is a pronounced ridge where the seal rides. the sleeve (IIRC) is chromed steel, and will not wear in like the cast (forged) iron crankshaft. do it once, and forget about it until the end of time.

[Dirtnap30]

yeah i never want this thing to leak again! pulling this tranny seems like its gonna be awful, I hope i don't have to resort to pulling the motor

[36brua]

This is the same mistake I made when I first dropped my M50 in, I just totally forgot it. Sure enough, every time I drove the car, I'd have about 2-3" wide puddle of oil right under the bellhousing.

Pulled the motor back out (had some other stuff to do), and put in a new RMS, with an SKF Speedi-Sleeve on the crank/seal shaft, hasn't leaked a single molecule since.

did you leave the flange on the sleeve or remove it ? thanks

[Jand3rson]

Left it on, there's no real reason to remove it. They're supposed to just snap off, but I've heard of a few people that when they tried to remove it, fucked up the sleeve itself. And at $45 a pop, you don't really want to do that too many times.

[Doughnut]

put in a new RMS, with an SKF Speedi-Sleeve on the crank/seal shaft, hasn't leaked a single molecule since.

*Goes outside to find 2 gallons of engine oil on the driveway*

:p

[36brua]

Left it on, there's no real reason to remove it. They're supposed to just snap off, but I've heard of a few people that when they tried to remove it, fucked up the sleeve itself. And at $45 a pop, you don't really want to do that too many times.

Thanks for the info