Flaky final drive

[Stan Walker]

'02 1150RT with 69,166 miles.

 

I drained the oil from my final drive this afternoon. The oil looked pretty normal and the magnet had captured a fair amount of fine dark goo, but no particles of note.

 

I started with a clean oil drain pan, as I always do. After the oil had finished draining I swirled the oil around and much to my surprise found an interesting bit of metal. It's about 1/8" wide, maybe .010 thick, 3/8" long and curled up like the main spring in a watch (about 2 loops worth). The material is non magnetic, shiny, and breaks easily.

 

I kind of looks like something left over from manufacturing. Still, after this many miles it's surprising that it would still be in there, and not ground up into dust. I did remove the ABS sensor before draining the oil today, first time ever out, so maybe it was hiding up there and I dislodged it.

 

The final drive feels good, no rough spots, minimal leakage from the pinion seal. The crown gear seal shows just the slightest trace of seepage, not enough to run, but not entirely dry either.

 

My inclination is to ignore it, but keep a close eye on the final drive. Maybe drain the oil again in a few more thousand miles.

 

Any thoughts?

 

Stan

[flat_twin]

....The final drive feels good, no rough spots, minimal leakage from the pinion seal. The crown gear seal shows just the slightest trace of seepage, not enough to run, but not entirely dry either.

 

My inclination is to ignore it, but keep a close eye on the final drive. Maybe drain the oil again in a few more thousand miles.

 

Any thoughts?

 

Stan

 

 

 

 

I'd do as you suggested, keep a close eye on it and check the fuid again. When mine failed there wasn't much warning at all. The vibration, noise and wet rear seal all came at the same time. From the time I noticed a clunky sound and a weird feeling in the footpegs till the time I knew I had to stop, I covered all of 50 miles.

If you detect any roughness at all when you rotate the wheel, it's toast. Your weepy seal may also be a sign of bearing failure on the way.

[smiller]

I haven't needed to do it yet myself, but as I recall from a tutorial I saw on the Advrider site it isn't very difficult or intrusive to take the rear drive down far enough to visually inspect the crown bearing. It might be worthwhile to do this before taking off on any very long trips.

[bigboy]

hey stan

I think it is probably part of the gasket because invarably

they are oversized ,my instinct tells me it is probably nothing to be concerned about.

kind regards

ansd stay upright

derek

[steve.foote]

As long as it's non-magnetic, I wouldn't worry about. Like you said, it's probably something from the original assembly.

[LJR]

Depends on your plans. Got any long trips coming up?

 

I get really clean oil out of the final drive. If it started getting darker, I'd probably rebuild it.

 

My inclination is to ignore it, but keep a close eye on the final drive. Maybe drain the oil again in a few more thousand miles.

 

 

Draining the oil in a couple of thousand is a good idea.

 

I've forgotten where you live, maybe a couple of thousand miles will be done this winter. Mine won't do a thousand miles till it warms up.

 

Keep us posted, it'd be nice to have an indicator of future bearing failure.

[Stan Walker]

Your weepy seal may also be a sign of bearing failure on the way.

 

Or maybe just the seal. Maybe....

 

I'll wipe it clean and keep an eye on it.

 

I think I'll also play safe and order both the crown bearing and it's seal from Chicago BMW. Expensive spares but I plan on keeping this bike a very long time.

 

I check my rear wheel for play and bearing roughness every time I check the air pressure (once a week). Heck, I'm already down there on the ground. I've been noticing a very slight bit of play (top / botton) and have been blaming it on the final drive pivot bearings. My visual inspection of them during my ongoing spline lube confirms they are toast. Perhaps I'll find out that they were masking some play in the crown gear bearing...... I won't know until I put it all back together.

 

Stan