Replaced rear main seal on 3.0 and have a leak

[80stech]

If there was a noticeable groove on the crankshaft that's not good. No it won't wear in. I actually need to do mine and haven't seen one of these yet up close but I was hoping it might be a teflon seal but I am starting to doubt that. The answer to the worn crankshaft would be either a sleeve or place the seal into the carrier slightly deeper or shallower to avoid the groove. Easier said than done though because the seal still needs to be perfectly perpendicular, although sometimes if your lucky and this is a known issue the replacement seal is designed to ride in a different spot when installed flush.

Also I think there is sensor or something on the left side of the block that can look like a rear main leak so maybe check that.

[e39_touring]

Originally Posted by 80stech

If there was a noticeable groove on the crankshaft that's not good. No it won't wear in. I actually need to do mine and haven't seen one of these yet up close but I was hoping it might be a teflon seal but I am starting to doubt that. The answer to the worn crankshaft would be either a sleeve or place the seal into the carrier slightly deeper or shallower to avoid the groove. Easier said than done though because the seal still needs to be perfectly perpendicular, although sometimes if your lucky and this is a known issue the replacement seal is designed to ride in a different spot when installed flush.

Also I think there is sensor or something on the left side of the block that can look like a rear main leak so maybe check that.

The seal doesn't seem to be teflon. It's a very delicate double lip seal and does not have the tension spring like most seals do. In fact, in the instructions, they tell you not to touch the sealing lip at all for risk of damage.

I've seen those speedi sleeves but can't find one ready-spec'd for the M54. I think my next time in, I'll recess the new seal a bit further and give that a shot. Hate to do this trial & error though since the pain in the a$$ it is to get to.

[aureliusmax]

Originally Posted by e39_touring

I've seen those speedi sleeves but can't find one ready-spec'd for the M54. I think my next time in, I'll recess the new seal a bit further and give that a shot. Hate to do this trial & error though since the pain in the a$$ it is to get to.

All you need to do is contact a manufacturer in the heavy equipment seal industry. They will need the new shaft diameter specification, width and a sample of the oil seal. A custom repair sleeve can be made and sent out.
I have ordered these before when repairing old fork-lift truck seals where there are no parts availability. Once you replace the seal and repair sleeve at the same time, and the crank case pressure is not over the limit, there will be no leaks. be sure to follow correct procedure such as use assembly grease on the parts.