K1100 Driveshaft "U" joint failure

[richo2006]

1993 K1100 with about 85,000 miles. I bought this bike in 2016 and have put about 50,000 miles on it. Second serious issue in about a week.

I had an interesting ride today. While riding west on I-94 in Michigan I heard a loud noise from the rear end. I called a friend that lives about 45 miles west to bring his trailer with his truck and my daughter that lives about 45 miles east to bring our truck. We loaded the bike and then swapped the trailer from his truck to ours.

After draining the final drive oil, there was no metal on the drain plug or in the oil. Of course, that leaves only the driveshaft. I removed the final drive and found the rear "u" joint had a catastrophic failure. The joint failed and the yoke was destroyed.

I was fortunate that the rear wheel didn't lockup and cause a high-side.

Is there any way to inspect and/or prevent this from happening again?

For some reason I'm unable to upload pictures.

 

[pglaves]

1993 K1100 with about 85,000 miles. I bought this bike in 2016 and have put about 50,000 miles on it. Second serious issue in about a week.

I had an interesting ride today. While riding west on I-94 in Michigan I heard a loud noise from the rear end. I called a friend that lives about 45 miles west to bring his trailer with his truck and my daughter that lives about 45 miles east to bring our truck. We loaded the bike and then swapped the trailer from his truck to ours.

After draining the final drive oil, there was no metal on the drain plug or in the oil. Of course, that leaves only the driveshaft. I removed the final drive and found the rear "u" joint had a catastrophic failure. The joint failed and the yoke was destroyed.

I was fortunate that the rear wheel didn't lockup and cause a high-side.

Is there any way to inspect and/or prevent this from happening again?

For some reason I'm unable to upload pictures.

This happened to Voni's R1100RS at 202,000 miles. I do think there are some warning signs. A slight click-click when the wheel is rotated by hand with the bike on the centerstand is a very good clue. Since hers failed I have removed shafts and manipulated the joints every 50K miles or so to check for emerging failure.

 

[richo2006]

Thank you Paul.

The final drive pivot bearings were also destroyed. I guess tomorrow I'll order a new driveshaft and two pivot bearings.

Regards,


Richard Flood

Commerce Township, MI

 

[52184]

After draining the final drive oil, there was no metal on the drain plug or in the oil. Of course, that leaves only the driveshaft. I removed the final drive and found the rear "u" joint had a catastrophic failure. The joint failed and the yoke was destroyed.

I was fortunate that the rear wheel didn't lockup and cause a high-side.

Is there any way to inspect and/or prevent this from happening again?

I had a similar failure on my ‘04 K1200GT sidecar rig, destroying the shaft yoke and both pivot pins on the paralever. In my case, the bike was overdue for a driveshaft spline cleaning and lubing. While the splines at both transmission and final drive still had grease, the splines on the center of the two-piece shaft were dry, corroded, and seized solid—the rear half of the shaft had to pulled out of the front using a press. Pre-failure symptoms included a change in feel of the rear suspension and a noticeable vibration during the 40 or so miles before failure. The failure was totally on me for deferring maintenance and trying to squeeze in one more trip, then ignoring the messaging/symptoms the bike was presenting.

When I installed the new shaft I made sure the phasing was correct (https://managedmobile.com/driveshaft-phasing-importance/ or https://www.drivelinesnw.com/part-trouble-shooting/vibration-analysis/phasing/) then paint-marked both parts of the shaft so they could be separated, cleaned and greased with moly paste, and reassembled in the correct phasing. That now happens every other year or at every 24k service, whichever comes first. And of course, the splines at the yokes get treated at the same time.

I don’t have a copy of the 12k or 24k service checklists handy at the moment but I believe those checklists only call for lubing the splines at each yoke, and don’t mention the middle splines. In theory, the design of the paralever is such that the pivot points of the yokes and the swingarm/final drive are concentric, so no length adjustment takes place as the swingarm moves up & down. I believe in practice it’s close, but not quite, so the middle splines need to be able to compensate. But, I’m not an M.E. so take that fwiw. For sure, regular cleaning and lubing of all the shaft splines is your best bet for long life on the shaft.

Good luck,
DeVern

 

[richo2006]

Thank you DeVern for your reply. I put 223,000 miles on a previous K bike without any driveshaft issues. The cross member of the u joint shows obvious sings of wear and pitting from lack of lubrication. I will need to pay closer attention in the future for any changes in noise and vibration and remove the driveshaft and manually check the u joint and of course grease the spines.

Regards,


Richard Flood