BMW R1200RT/R1250RT Forum

Just doing final drive oil for the first time (100k service on my 08 RT) and noticed some rust on the u joint.

Perhaps from a slightly deformed boot?

Should I apply spline grease to the rusty areas or something else? Is it possible to apply some grease or silicone to the outside of the boot to make it more water tight?.




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craig.dougall.1 wrote: Just doing final drive oil for the first time (100k service on my 08 RT) and noticed some rust on the u joint.

Perhaps from a slightly deformed boot?

Should I apply spline grease to the rusty areas or something else? Is it possible to apply some grease or silicone to the outside of the boot to make it more water tight?.

Re: Final drive service: some rust should I be worried?Re: Final drive service: some rust should I be worried?Re: Final drive service: some rust should I be worried?Re: Final drive service: some rust should I be worried?Re: Final drive service: some rust should I be worried?Re: Final drive service: some rust should I be worried?Re: Final drive service: some rust should I be worried?Re: Final drive service: some rust should I be worried?Re: Final drive service: some rust should I be worried?Re: Final drive service: some rust should I be worried?


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Looks bad. My 07 R looked the same. In my case it wasnt rust, but overheated/burned moly lube. I had a transmission seal leak that washed all of the lube out of the Ujoints. I pulled the shaft and at the distal U joint everything was ok, but at the proximal U joint there was a "catch" articulating it back and forth. The only way to be sure is pull the shaft, if its like a 07 R that means pulling the fork. Once in hand articulate all the U joints. If they articulate free of "catching" and grinding you're good, otherwise you're on borrowed time. Google R1200 shaft failure and you will see the catastrophic consequence of a U joint failure, serious injury to your bike and more importantly to yourself.

I also heard that instead of pulling the shaft, a real pita, you can just put the bike on center stand w the final drive all buttoned up, put the bike in neutral and start it up. If the rear wheel rotates slowly while in neutral thats a good indicator there is no binding and you're ok.

In my case I had a bad shaft that was confirmed at a local shop. I could spend over $1000 for a new oem non serviceable shaft or send my shaft to Brunos Driveshaft in Canada. For $400 he replaces the oem "lifetime lubricated" joints w serviceable joints. I went w bruno who did a great job, but it was a pain shipping internationally and took about 3 weeks.

Goodluck

I wouldn't be overly worried about that Wayne. It's surface rust on a very substantial & strengthened component- if it was in the actual joint it could cause problems but that will shift easily. Try coating it with a decent white Lithium grease instead of oil. This sticks better & will remain in place for longer when the component gets warm. It does appear that the rubber boot has been badly fitted & possibly allowed water ingress.