Final Drive seal replacement

[DarkCloud]

The left side of the final drive on my R1100GS has a very slow leak.
How much of a job is it to replace the big rubber O ring that BMW wants $6.30 for? Can I do it without removing the final drive? Thanks, JON

[ragtoplvr]

Easy, takes another 20-40 minutes over time to RR rear wheel'

Hint, Harbor freight has metric socket bit kit that not only has the 7MM size you need for this repair but the big socket you will need someday for the pivot bearing.

The assembly with the ring ear and bearing can easily be held in position with one had while the other gets the Allen head screws started and lightly snugged up. Then you have 2 hands for final torque

Male sure you can remove fill plug before starting, sometimes they stick.

Rod

[TrailingJack]

The left side of the final drive on my R1100GS has a very slow leak.
How much of a job is it to replace the big rubber O ring that BMW wants $6.30 for? Can I do it without removing the final drive? Thanks, JON

I'm wondering the same thing.
Mine started leaking while riding some gravel/dirt over the weekend.

It was showing up on the tire and upon further inspection, appeared to be leaking around the seal. After deciding to ride back to our base, I stopped and bought some gear oil, figuring that I could nurse it home (250 miles) as long as I checked it occasionally.

Funny thing was, it leaked a few drops onto the ground when it first started and at the auto parts store but after we got back to our base (hotel) and wiped it clean, checked the level (which was still up to the threads), it has barely leaked at all. I rode almost 300 miles back home and it had hardly gotten wet, let alone dripping onto the ground. The level is still good.

What gives?
It's possible that it was slightly over-filled the last time which I suppose could damage the seal.

There doesn't seem to be any other signs of damage - no noise, wobble/freeplay or abnormal heating of the FD. No metal in the oil.

Advice?

[TrailingJack]

Turns out, my leak was nothing more than the big seal around the crown gear.

Got lots of help over at ADV.
Here's the thread:

http://www.advrider.com/forums/showthread.php?t=585299