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Rear engine seal/ clutch

arkmark

New member
So I’ve got a good amount of oil leaking from between the engine and transmission. Without disassembly I’m thinking rear main seal is leaking and since I’m sure thats getting oil on the clutch I also plan to replace it and the slave cylinder while I’m there. Any words of wisdom before I tackle this job from someone who’s been there before would be appreciated. Particularly any tips and tricks. As a bonus if your in the central Oklahoma area and familiar with this job I’ll buy you a cup of coffee to swing by and lend a hand.
 
Assuming it's a 1200
Very likely the counterbalance shaft seal.
Lots posted on youtube on how to.
 
Yes, it is a 2012, 1200. I’ll add the counterbalance shaft seal to my order list.
 
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How many miles? If it’s just the CB seal, do you really want to spend a lot of dollars on clutch bits? And, if main seal not weeping... I wouldn’t touch it.
Parts are pricey, but readily available and I wait until a full diagnostic is done before I put that order in.

Are you seeing oil on ground or just weeping at mating surfaces of engine/ tranny? A weep looks bad, a regular puddle is way diff to me. Is clutch slipping?
 
I'd add the transmission input shaft seal to the list as well. Agree with above, if the main seal is not leaking I would not mess with it. Straight forward job good luck.
 
It’s got 120k miles on it and leaves a puddle on the ground. Clutch isn’t slipping yet but there’s no way that it isn’t getting oil coated from the leak. I do a lot of bike work at the house and can’t tie up room for a long time waiting on parts, so I want to have all the parts before I start since I’ll be loosening work while working on my own. I do predominantly harley work mine is the only bmw that I work on so its still pretty new to me. I rebuilt the rear end about 3 years ago other than that just regular maintnance is all its needed.
 
I had transmission oil leak coming out on the "shelf" that sticks out from the crankcase below where the transmission mates to the engine. The bike had 188,000 miles on the original clutch so I sourced a clutch and all the seals, 4 I think, that go into the back of the engine or front of the transmission. Its a lot of disassembly to remove the transmission and expose the clutch and would be a bummer to have another seal leak in the future or the high mile clutch start slipping. My only gotcha was I did not see that BMW recommends replacement of the one-use bolts that secure the flywheel so there was a wait on those bolts before reassembly.

Turns out in my case the transmission input shaft bearing was in failure. The oil leak was there but the real problem was the bad bearing shedding metal into the transmission an unknown period of time. I sourced a low mile fleabay transmission and put it all back together.

This is not a hard job just a lot of disassembly/reassembly in particular order. Also think about how to support the front sub frame when the rear sub frame is unbolted and pulled away. The same bolts secure both to the engine. I had a friend that had done this job and he lent me the 4 threaded studs he made that did this.

RT Tranny Replace (2).jpg
 

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