large pieces in drained oil '97 R1100RT

[SULLY]

Drained the rear drive oil, and found many pieces of steel attached to the magnet on the drain plug. 2 of them measure ~5mm in size.

I've never had a problem, but my mind is screaming "rebuild the drive unit!!!". It's 85 miles to my mechanic, but I'd rather he handle it if I can't get a decent rebuilt unit delivered to me via UPS.

Please share your thoughts and opinions; I found nothing after searching the forums here--- maybe I was using the wrong search term?

Sully, itching to ride up here in the currently snow-free Great White North.

 

[breyfogle]

Drained the rear drive oil, and found many pieces of steel attached .... 2 of them measure ~5mm in size.....

Are you sure you mean 5mm (almost 1/4 inch) ? If so, something major has failed internally, even if there is no external oil leak, yet. I would definitely NOT ride the bike until the FD is repaired/replaced.

 

[PGlaves]

Almost certainly the cage for the big ball bearing has failed. This happens when the balls fail and get stuck. The drive would be totally unreliable at speeds over 5 mph.

Take it off. Take it in or send it to Tom Cutter at Rubber Chicken Racing Garage, Get it fixed.

This, by the way, is why I change final drive oil every 6K with the engine oil. I can see debris before outward signs strand me.

 

[Walking Eagle]

Ouch!

What else can I say? Except. . .

Good luck.

Walking Eagle

 

[globalrider]

Almost certainly the cage for the big ball bearing has failed.

Paul, is the cage made of steel? I have not had any of my FDs fail, so I wouldn't know.

To the OP, spike the oil with DC M Gear Guard at 5% and it should last longer. I have nothing on my FD drain plug between changes. I also use dino type Bel-Ray 90.

 

[PGlaves]

Paul, is the cage made of steel? I have not had any of my FDs fail, so I wouldn't know.

To the OP, spike the oil with DC M Gear Guard at 5% and it should last longer. I have nothing on my FD drain plug between changes. I also use dino type Bel-Ray 90.

Yes, the cage is bright steel, and very brittle. At one time there was a school of thought that the cage was breaking causing the failures. I never believed it. Absent a great deal of force that cage won't break and the only thing that will apply a lot of force is the bearing turning with a jammed ball. It is clear that the typical failure mode is chipping of the races followed by surface damage to the balls. Eventually a ball jams and the rest follow along behind like a train wreck, breaking up parts of the cage.

So little metal flakes on the magnet are chips off the races. The first sign. A heavy paste is usually worn off the balls, the second sign, and shiny strips or chunks are from a broken race. Little hairs are normal for the first many K miles, and are from the gears wearing in to each other.

If he has chunks they are either race chips or broken pieces from the cage.

 

[SULLY]

thanks, guys!

the two largest pieces are 5mm on their long side, and both have convex radii showing--- hopefully confirming Paul's opinion that it's only a bearing race, not broken gears.

Took the wife out for a Mother's Day ride on it today and it performed flawlessly, but I'll park it until I straighten it out.

It only has 61K miles on it; after replacing the right cylinder head's base gasket for a serious leak at 55k, I'd like to keep this scooter for another 100k.

Thanks, y'all, for your input.

Sully