Originally Posted by siclmn
A picture is worth a thousand words. Here is mine
THAT is just like my bike was, at least the tranny output seal. The rear drive input seal was also leaking but I had to take the drive out and set it on its end to see it. But that is not Flyingkiwi's problem, his leak is on the other side.....!
The cause: a bad Driveshaft which caused the seals to go. The cure.....new Driveshaft, Seals, Pivot bearings, Etc....and as I was taking it apart anyway I went as far as the Clutch O-Ring. That one was not leaking but was certainly showing signs of degradation at 43,000 Km.
Now why did the driveshaft fail? Because the previous "Mechanic" DID NOT phase it correctly, a procedure that IS NOT in the BMW Shop Manual or the Clymer's.....! That same "Mechanic" DID NOT tighten down the slave cylinder and also FORGOT to tighten the left side swingarm pivot pin......!
The only sign of the failing driveshaft, besides the leak, was a vibration at high speed, that is 160 Km/h +, but if you have any suspicion that this is what may be happening with your bike, DO NOT ride it like that, you may wreck more than just seals, possibly the rear drive and tranny bearings, and maybe the swingarm too if the U-joint fails completely. That last one happened to me on my R100GS, but just lucky I was not doing 70 MPH when that U-Joint self destructed and smashed into the swingarm.