Bad drivetrain chatter with new clutch

[Hotmop]

Hey all. 

 

I fear I've done something really wrong. Looking to know if anyone's seen this before.

 

97 R1100RT with about 48k. Replaced the clutch with the Sachs kit from BBY. Now, when feathering the clutch, I'm getting serious chatter in the drivetrain. 

Video attached. 

 

Things done:

• Sachs clutch pack
  • Followed the Chris Harris youtube video
  • Referenced factory shop manual and Haynes manual
• Lubed splines, first time, looked in great shape
• Replaced clutch push rod with newer design with anti-rattle felt
• Replace neutral switch
• Adjusted clutch per "12mm and 7mm" settings
• Install Nushings for final drive mount (no BMW torque socket setup. But pin didn't move when lock nut tightened)
• Lubed gearbox output and final drive splines
• Pretty sure I got the u-joint phase correct
• Synthetic gear oil for gearbox and final drive.
• Engine oil/filter.
• Rebuilt rear brake master cylinder (assuming unrelated, but wanted to be thorough) 

 

Resulting behavior:

• Clutch lever is WAY lighter than before. Almost feels disconnected but works.
• Bike launches fine if done promptly.
• Roll-on highway-speed slippage seems gone (original reason I replaced clutch)
• When feathering a launch or "bumping" along coasting in traffic I get a violent chatter in the drivetrain. 

 

Any ideas? Has anyone seen this before? It's making me sick that I messed something up.

 

Best, 

Matt

[Jim Moore]

Mine did a similar thing, although I'm not sure it was quite that bad. It went away after a time. I think it might have been the new parts bedding against the old parts. I'd ride it for a few days and see how it goes.

[dirtrider]

8 hours ago, Hotmop said:

Hey all. 

 

I fear I've done something really wrong. Looking to know if anyone's seen this before.

 

97 R1100RT with about 48k. Replaced the clutch with the Sachs kit from BBY. Now, when feathering the clutch, I'm getting serious chatter in the drivetrain. 

Video attached. 

 

Things done:

• Sachs clutch pack
  • Followed the Chris Harris youtube video
  • Referenced factory shop manual and Haynes manual
• Lubed splines, first time, looked in great shape
• Replaced clutch push rod with newer design with anti-rattle felt
• Replace neutral switch
• Adjusted clutch per "12mm and 7mm" settings
• Install Nushings for final drive mount (no BMW torque socket setup. But pin didn't move when lock nut tightened)
• Lubed gearbox output and final drive splines
• Pretty sure I got the u-joint phase correct
• Synthetic gear oil for gearbox and final drive.
• Engine oil/filter.
• Rebuilt rear brake master cylinder (assuming unrelated, but wanted to be thorough) 

 

Resulting behavior:

• Clutch lever is WAY lighter than before. Almost feels disconnected but works.
• Bike launches fine if done promptly.
• Roll-on highway-speed slippage seems gone (original reason I replaced clutch)
• When feathering a launch or "bumping" along coasting in traffic I get a violent chatter in the drivetrain. 

 

Any ideas? Has anyone seen this before? It's making me sick that I messed something up.

 

Best, 

Matt

 

 

Morning Matt

 

Did you clean the friction surfaces of the clutch cover & pressure plate using brake clean before installing?

 

It definitely isn't a drive shaft phasing issue.

 

At the moment about your only option is to ride the bike to see if it will clear up, try to launch at a high enough RPM & aggressive enough to reduce or eliminate the chatter.

 

Maybe even try using the clutch for braking a few times (pull clutch lever in, down shift to a very low gear, allow engine RPM to drop to idle,  then use a little clutch slippage to slow the motorcycle).

 

If you can find the original supplier of the clutch parts  possibly call them for advise, then if possible, send them your video.

 

If the chatter problems don't go away after some riding & a few aggressive launches then you might have to go back in & inspect the installation (you will probably need enough launches & riding to leave witness marks to see anything odd though) 

 

 

[Hotmop]

@Jim Moore, good to know I'm not completely alone. Give me some hope that it might just be a bed-in sort of thing. 

 

@dirtrider, I don't remember doing any extra cleaning to the plates, so that could be a factor. They seemed bare metal clean, but of course there was likely some protection on those surfaces. I did a bit of downshift clutch braking on the way to work today. 5 to 4 and 4 to 3 were fine. Going 3 to 2 got me this chatter on the roll when letting the clutch lever out.

 

I can surely launch it with zero chatter if I just go. It's not overly aggressive launch, just no slipping along. I'm going to try some slipping at higher speed to see if I can induce some wear without chattering too much. 

[fatbob]

Your new clutch probably has the longer splines, these take a while to wear into the transmission input shaft that is worn.   I put the BBY clutch kit on my ‘03 1150 and experienced the same thing.    It is almost cleared up completely after 4000 miles.  

[Hotmop]

@fatbob, Thanks for the insight. I've been riding to work for a few weeks now and it's fine if I just get going. Just no slow speed coasting and slipping along. I'll stay with it and report back after a few K.