Clutch conundrum

[gerardb]

My first post, so please be kind!
Got my new 1995 R1100R a few weeks ago (140,000km on the clock) and love it - after 5 K bikes and one F bike, it handles like a sports bike in the corners, but cruises effortlessly - love it.

But the clutch died! Working one minute, then when I pulled in the clutch lever, no pressure, could not disengage the clutch. First I thought the cable had broken, but it's fine (this is the cable model), then checked the actuating lever at the back of the gearbox, also appears fine, but now it takes no pressure to pull in the clutch lever, and pulling the lever does not disengage the clutch.

The ride home was fun - starting off at the lights in gear, with the starter motor, then judging revs to "clunk" between gears without a clutch - very interesting....

Any ideas? After looking at the schematics, I suspect the fingers on the pressure plate may have broken, but it all happened so suddenly and without any strange noises - it's got me baffled, and I'm not keen on spending $1500-$3000 for a new clutch, so may have to do it myself.

[gerardb]

I meant to say I think the fingers on the diaphragm spring may be broken, not fingers on the pressure plate!

Don't know how they could all break at once though - and no noises before or after to tell me something was wrong.....

[CycleRob]

gerardb, I got a heads up when talking to your buddy Mike S. about your clutch problem.

I found a good source for the parts and pics here:
http://www.maxbmwmotorcycles.com/fiche/ ... d=08102012. Select "21-Clutch" from the menu and you're there. Here are the release assembly parts:



There is one part that could fail "all at once" (actually, chew itself to metal chips while you were riding) and that is the throwout bearing (part 2 above, in detail below). That is the normal service life for a 17 year old 140,000km of engine RPM spins bearing asked to survive in a hot cavity that sometimes gets cooled off with gritty road spray thru the 17 year old (cracked?) rubber boot (Part 5). The throwout bearing:


It would be worth it to make the easy shots first and remove the release assembly from the tranny for inspection of that throwout bearing and the pushrod. If that's the problem, you can fix it with just over $100 worth of parts. BMW says:
"This part replaces the older throwout bearing AND piston. The 167 is a combined/sealed unit. When installing this part on your older clutch rod, there's a bushing that is not needed and must be removed. Otherwise, replace the clutch rod at the same time as it made for the new 167 part".

If there's no damage in the release assembly (I hope there IS!!), the problem gets ugly . . . and co$tly. The diaphragm spring (part 4 below) certainly does look like it could fail, specifically the 3 sided center bracket that accepts the clutch pushrod. I have never seen the actual part, but from the diagram it looks like maybe it either collapsed, wore thru or attachment spot welds broke.



You will have to remove the tranny to fix it if the release mechanism is OK.

[gerardb]

Excellent, thanks CycleRob, this makes the most sense of all other possibilities. I did have an "aha" moment last night, thinking it might be a crack in the actuating lever, allowing it to move but not depress the clutch, but checked that and no - the lever is fine, so your throwout bearing solution sounds like it's a winner.

It looks very crowded in there - I think I will remove the wheel, muffler and footpegs to get my fists in there.

Thanks heaps

[captaincable]

Have you had any luck finding the problem?
Mike

[gerardb]

Hi Mike,

have not got to the solution yet - I sent away for the throwout bearing and other bits from the UK (1/3 the price of Australia!) so expect them this week. I am working on a setup to raise the bike to a workable height (will build a bench I expect).

Thanks for your inspiration about the throwout bearing - it's the only logical solution I can see - but we'll see when we get in there.

The local bike shop who work on a few BMs says it's a 15 hour job to replace the clutch, and I think I can do it in that time myself, so am gaining more courage.

will probably be back with another question soon, so thanks for your interest.

cheers,
Gerry

[captaincable]

CycleRob is the brains behind it I just passed on you were having a problem, He has helped many people with their bike. Hope everything works out. Mike

[gerardb]

WOOHOO!

Pulled the R1100R apart and finally got to the offending throwout bearing - and just as CycleRob and Mike had predicted, the bearing had collapsed. The guy I bought the bike from told me the clutch had been replaced 20,000km ago, and it may have been, but why didn't they replace the throwout bearing at the same time?

Anyhow, here is the offending part and the new one (if I can figure out how to post a picture)

Thanks guys - it was a big job, but a new clutch would have been a huge job!

[captaincable]

Glad you got to the bottom of it , but as I said earlier CycleRob is the one who diagnosed the problem. Have fun and ride safe. Mike