another FD issue

[roostershooter]

Is this picture indicative of a leaking seal or perhaps a bearing issue, there is not much fluid on the wheel and only about one or two drops of fluid on the bottom of the boot. Any one have any thoughts?

 

[PGlaves]

Is this picture indicative of a leaking seal or perhaps a bearing issue, any one have any thoughts?

That is a typical symptom of gear oil seeping past a seal: either the final drive pinion shaft seal or the transmission output shaft seal. Oil seeps into the swingarm and eventually seeps past the rubber boot.

With these seals - sometimes it is a bearing problem - but the vast majority are simply seeping seals. I would remove the tie from the front (large) end of the boot, peel the boot back, and see if it is possible to see a stream of oil which has come rearward from the transmission. That is at least a clue.

Then I would thoroughly clean the oil off the inside of the boot and the nose of the final drive where the shaft attaches and reinstall the boot with a new tie. Then see how long it takes to see more seepage.

This is a problem that can seep for a long time before you need to do anything about it in most instances I've seen.

What type and weight oil is in the transmission and final drive??

 

[roostershooter]

Thanks for the reply Paul, the last major service was performed at 12 k miles by my local BMW dealer. The bike now has 21k on the clock. I would assume that the tech used BMW fluids and that they were of the correct viscosity. I did peel back the boot and only about two drops of fluid were in there. I will keep an eye on it.

 

[DrPaul]

Is this picture indicative of a leaking seal or perhaps a bearing issue, there is not much fluid on the wheel and only about one or two drops of fluid on the bottom of the boot. Any one have any thoughts?

My 2002 R1150RT pinion seal is very sensitive to FD fluid level. When it is filled to the TOP of the fill plug threads, it seeps. When the level is at the lower threads it DOES NOT seep. I run Castrol Syntec 75W-90 in mine.

Dr. Paul

 

[bikerfish1100]

most acurate fill method is to measure and pour. Only slightly less accurate is to fill to bottom of threads; has worked for years on all models of BMW, but have never heard of using top of threads as a mark. Probably for good reason.