Clutch noise

I am hearing a rattling noise from my 2006 R1150R 10,000 KM or 6,000 miles on it when I am holding the clutch lever in. It seems to be more prominent after the bike is warmed up, in fact I usually can not hear it at all when it is cold. To me it sounds like a bad release bearing but it does not do it all the time. Some of my friends think it may be normal for this bike. I have been looking at parts blow ups but can not locate the throw out bearing I am thinking it must be part of the slave cylinder. If anyone here can throw some light on this it would be greatly appreciated.

Bill

No response

It would be nice to know if the lack of response to this thread is because no one has an opinion, or is it something I said. As per another thread I changed the fluid in the hydraulic clutch but it did not seem to make a difference. Am I chasing the wrong thing? Could this be cam chain rattle?

Typically the rattle you describe is an indicator of worn clutch hub splines, a common problem with 6 speed oilhead transmissions.
An enormous amount has been posted & discussed on this subject on many forums.
Google is your friend.

A bad release bearing (part of the slave) will make a screeching noise or cause leaking fluid along the input shaft.

The bike has years, but only 6K. Hard to imagine it's a wear issue. It may go away with more ride time or not as all the lube product at the slave to pushrod interface has no doubt aged.
The Hexheads get a knocking tap with clutch released as the pushrod ends mushroom,the Oilheads usually spin the seal and you lose the clutch when the fluid leaks.
Did you flush the slave with the bleed line or just change master cylinder content...and what color was the old fluid?

But seriously...an 1150R with 6K?

Easy enough to pull the starter and check for radial spline play.

On the 1998 R1100RT I just added to my fleet a "bad clutch" ended up being a blown up release bearing. When I adjusted as much play as I could out of the system it made a horrible sound as the clutch rod spun on what was left of the release bearing. Luckily on this bike the splines are ok though a little rusty and dry. Clutch disc does not look like it could 280K miles on it. OP says bike was never apart before this but....

noise

billdor said:

It would be nice to know if the lack of response to this thread is because no one has an opinion, or is it something I said. As per another thread I changed the fluid in the hydraulic clutch but it did not seem to make a difference. Am I chasing the wrong thing? Could this be cam chain rattle?

Click to expand...

Please verify if the noise is evident when the clutch lever is pulled in or at rest.

It's normal to hear some noise with the clutch lever at rest. The noise should diminish as the lever is pulled in. Again, totally normal.

RPGR90s said:

Please verify if the noise is evident when the clutch lever is pulled in or at rest.

It's normal to hear some noise with the clutch lever at rest. The noise should diminish as the lever is pulled in. Again, totally normal.

Click to expand...

Indeed a slight clatter in neutral, clutch not pulled, is normal. Noise when the clutch lever is pulled is not normal.

henzilla said:

The bike has years, but only 6K. Hard to imagine it's a wear issue. It may go away with more ride time or not as all the lube product at the slave to pushrod interface has no doubt aged.
The Hexheads get a knocking tap with clutch released as the pushrod ends mushroom,the Oilheads usually spin the seal and you lose the clutch when the fluid leaks.
Did you flush the slave with the bleed line or just change master cylinder content...and what color was the old fluid?

But seriously...an 1150R with 6K?

Click to expand...

Thanks for the reply
Can the pushrod lube be replaced? I completely flushed the fluid with the bleed line and it was a really dark color, I doubt it had been changed since new.

GSAddict said:

Typically the rattle you describe is an indicator of worn clutch hub splines, a common problem with 6 speed oilhead transmissions.
An enormous amount has been posted & discussed on this subject on many forums.
Google is your friend.

A bad release bearing (part of the slave) will make a screeching noise or cause leaking fluid along the input shaft.

Click to expand...

Thanks for the reply
Would the clutch hub splines be worn with only 6k miles?

RPGR90s said:

Please verify if the noise is evident when the clutch lever is pulled in or at rest.

It's normal to hear some noise with the clutch lever at rest. The noise should diminish as the lever is pulled in. Again, totally normal.

Click to expand...

The noise seems to be mostly with the lever at rest but I have also noticed it when the lever is pulled.

Clutch rattle

I'm no expert but I have experienced some clutch/transmission rattle at idle once the engine and transmission are warmed up. It is a signal to me that the throttle synch isn't spot on. Varying crankshaft speed at idle can result in a driveline rattle. If you pull the clutch lever in and the noise stops, that could be the issue. Is the idle low? Do the mirrors vibrate at idle? Do the bars shake a bit at idle?
I'd make sure all the idle adjustments are set properly before I would start looking for clutch problems at 6000 miles.
My $.02

If at idle, and in neutral, clutch not pulled - this from the guru Oak Okleshen back in 1974:

"The noise is the result of an unloaded transmission and the backlash in the mating parts clattering slightly due to variances in engine speeds when at idle. The engine, though we think of it as running at a constant speed, varies in a miniscule amount when it is unloaded and at low speeds near idle. This happens between the power pulsations from the pistons. The flywheel helps to prevent the uneveness but does not cure the problem entirely for it would take a much larger and heavier flywheel than necessary to make the machine run properly and would detract from acceleration performance. As a result, the engine pulsates and the transmission attempts to run at a constant speed. Between pulsations the backlash in the transmission causes the components to clank lightly and cause noise.

The noise can become more noticeable if ...unbalanced left to right. This causes engine pulsations to become more uneven and, hence, there is more noise in the transmission in neutral, clutch engaged."

This is especially noted for Oilhead transmissions. Initial attempts to quiet the trannys with O rings failed as soon as the O ring hardened. The clatter is evident in all dry clutch BMW transmissions.

Thanks for all your help guys, I guess I just have to put up with it. I have been a licensed automotive mechanic all of my life and it bothers me when I hear strange noises coming from any machine. To me a noise or rattle is a sign of something wearing or pounding and it can't be good. I believe you are absolutely right about the trans rattle Paul but for that to happen the clutch has to be engaged with the trans in neutral, but I also have a similar noise with the clutch dis-engaged and the trans in gear which in my mind can only be the release bearing. I probably have two separate problems. I also notice that I have little or no free play in the hydraulic clutch lever which could cause undue wear on the release bearing and I can not see a way to adjust it. Any way thanks again for your help and I will have to see if it gets any worse come spring as the riding season here is coming to a quick halt.

Bill

billdor said:

Thanks for all your help guys, I guess I just have to put up with it. I have been a licensed automotive mechanic all of my life and it bothers me when I hear strange noises coming from any machine. To me a noise or rattle is a sign of something wearing or pounding and it can't be good. I believe you are absolutely right about the trans rattle Paul but for that to happen the clutch has to be engaged with the trans in neutral, but I also have a similar noise with the clutch dis-engaged and the trans in gear which in my mind can only be the release bearing. I probably have two separate problems. I also notice that I have little or no free play in the hydraulic clutch lever which could cause undue wear on the release bearing and I can not see a way to adjust it. Any way thanks again for your help and I will have to see if it gets any worse come spring as the riding season here is coming to a quick halt.

Bill

Click to expand...

If that were my bike Bill, I would do a preemptive inspection of the hydraulic slave cylinder. The bearing is these is know to fail. They seem to get minimal grease from the factory. When that bearing collapses you may feel a mushy clutch for a few pulls and then the piston moves to take up the space. But then most times the clutch is pulled the piston can spin, ruining the seal. Then fluid leaks, and in factory configuration it has no place to go except to flow along the clutch rod into the bellhousing and contaminating the clutch.

I would pull the slave cylinder and inspect the bearing. If failed, get a new slave. If not observe the skimpy grease and properly lubricate the bearing. And as a future precausion I would file a slight notch at the bottom of where the slave meets the transmission case. This is an excape for any fluid that would ever leak in the future, saving the clutch from harms way.

One trick to make the job easier is to remove the two mounting bolts and then rotate the slave just a bit - which gives clearance for the allen wrench needed to take loose the banjo bolt on the pressure line. You can leave the bleed line attached and just snake it out with the slave. On most models there is wiggle room to get it out without disturbing the swingarm.