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Driveline slop

S

seniorasi

Guest
Hey! Just wondering if anyone could give me a heads up on my drive line? I am experiencing a thud that sounds like a ball peen hammer tapping the final drive case when I let the clutch out. I can also hear the noise when adding throttle or letting off the throttle, just not as loud. I put it on the center stand and jacked the back wheel off the ground, put it in 1st gear, opened up the drive shaft boot and took out all the slop in one direction. I then turned the wheel the other direction and noted the amount of slop in the final drive and the transmission. The final drive has about 3/4 of an inch before it contacts the transmission, the transmission has about 1/2 inch slop. My question: Is this normal slop?

Notes: 1983 R100RT: Measurements for final drive taken on the side of the tire, on the output flange for the transmission. I inspected the splines at both ends of the final drive and the transmission splines when I replaced the swing arm bearings. All appeared serviceable. I also replaced the drive line fluids at that time. I checked the drive shaft flange bolts and they are tight. I've put 1,000 miles on the bike since doing the work/purchase. I don't know for sure, but I think this is a problem that is getting noticeably louder as I don't recall hearing it when I first put the bike into service.
 
I had that huge spring in the cush driveshaft break which made all sorts of noise and slop yet the bike was still drivable.
 
Another area to check carefully is the connection of the final drive to the wheel. It attached by rivets and if they are worn or broken it will create what you describe. If the final drive was ever replaced, the chances of this problem are significant. Many mechanics don't have the tools or the experience to properly install the rivets.
 
Another area to check carefully is the connection of the final drive to the wheel. It attached by rivets and if they are worn or broken it will create what you describe. If the final drive was ever replaced, the chances of this problem are significant. Many mechanics don't have the tools or the experience to properly install the rivets.

I appreciate the "heads up" on this one. No smoking rivets though. It is one area I hadn't thought to examine carefully prior to writing the thread.
 
I had that huge spring in the cush driveshaft break which made all sorts of noise and slop yet the bike was still drivable.

Hi, thanks for the input. I don't think that is the problem because everything seems to be tight after contacting the end of the transmission lash.
 
I have a similar problem in my '74 R60/6 [my thread on pg 2], noticeable backlash that can be heard when letting off and resuming throttle - measured backlash on wheel rim - see the pic I took.

Today, I pulled the rear wheel to examine the final drive spline and the drive coupling [riveted to hub]. On the pressure side of the teeth on both, there is approximately 1mm of wear [a total of 2mm]. There is minimal backlash when turning the drive spline - so the majority of my problem is the splines themselves.

I talked to Hans at BMW Hucky today and ordered both pieces, as well as ten new rivets. Riveting the new drive coupling into the hub won't be too bad to do, but the welds on the ring gear will have to be ground off the old drive spline, and the ring gear welded to the new one, and the proper tooth contact reset between the ring and pinion gears. Not too difficult, but more time to do. I'm putting new seals and wheel bearings in , while I'm at it.

You may want to remove your rear wheel and examine your splines.
 
I have a similar problem in my '74 R60/6 [my thread on pg 2], noticeable backlash that can be heard when letting off and resuming throttle - measured backlash on wheel rim - see the pic I took.

Today, I pulled the rear wheel to examine the final drive spline and the drive coupling [riveted to hub]. On the pressure side of the teeth on both, there is approximately 1mm of wear [a total of 2mm]. There is minimal backlash when turning the drive spline - so the majority of my problem is the splines themselves.

I talked to Hans at BMW Hucky today and ordered both pieces, as well as ten new rivets. Riveting the new drive coupling into the hub won't be too bad to do, but the welds on the ring gear will have to be ground off the old drive spline, and the ring gear welded to the new one, and the proper tooth contact reset between the ring and pinion gears. Not too difficult, but more time to do. I'm putting new seals and wheel bearings in , while I'm at it.

You may want to remove your rear wheel and examine your splines.

I'll check it again. Where can I view your thread?
 
I have the same problem with my 83 R100RS. The drive line seems to have no play, but when I let out the clutch I get the same noise that you do.Iremoved the cush drive from the driveshaft and found the coupling worn qiite a bit. I haven't replaced it yet but i'm sure this is the problem. Once you remove the final drive you need to compress the spring by pushing the splined coupling forward & removing the circlip that retains it.then let off the spring tension & emove the coupling & spring. If you need any pics of the compression tool, email me. anhnam_us@yahoo.com
 

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