Clutch help......please!

GarMc

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Hi newbie here with what may be a daft question.
I've owned my GS for just over two years but recently the clutch started slipping under load around 4K rpm.
I fitted a new Kevlar disc, new pressure plate and cover plate, diaphragm and clutch hose.
Finished putting it back together today aaaaaaaaaand the clutch is still the same!

Anyone any suggestions? Please, before I burn the bike.
Clutch was a b!tch to bleed, even with a bleed nipple.
Also during reassembly the slave cyl wouldn't seat flush with the 'box, had to wind it the last 8~mm in using the three retaining bolts / machine screws.
Thanks in advance.....

PS Couldn't see a reason other than the 74K Km the bike has covered and possibly lever hitting inside of hand guard for a while post Pheasant strike!
 
Was the centre plate just worn or was it contaminated with brake fluid ?


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Friction disc worn down to the rivets and bone dry.
New disc is Kevlar oil and heat resistant from Motobins with Sachs spring, pressure plate and cover plate.
Replaced the hydraulic hose with a Venhill one because the banjo where it connects to the slave cylinder was badly rusted under the foam.
 
The clutch push rod is definitely seated properly in the slave ? (Inside the little bearing?)


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I’m thinking that somehow when you had to wind the slave in, you were partially releasing the clutch hence slipping.


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That's kind of my thoughts too however it appeared to seat ok. Slave is going to be a git to access now.....
 
Clutch fluid in the middle of the bullseye.
Thinking about it this morning is it possible I have a stuffed slave cylinder with a slightly sticking piston?
Could that have contributed to the original failure?
I think I should at least buy a rebuild kit.
Also noticed late last night that the bleed is now passing fluid, which it never did before.
I removed the cap to try bleed it to make 100% sure all air is out of the system and there was fluid behind the cap. It was dry when I bled it.
I'm guessing I should do both of these first.
 
I’m thinking that somehow when you had to wind the slave in, you were partially releasing the clutch hence slipping.


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That's perfectly normal... The piston is extended and is retracted when refitting.

I'd check the drive shaft. The rubber bonding on the shaft can fail.
 
I removed the cap to try bleed it to make 100% sure all air is out of the system and there was fluid behind the cap. It was dry when I bled it.
I'm guessing I should do both of these first.

Why would air in the system cause the clutch to slip.... Air in the system would cause the opposite problem and cause difficulty disengaging the clutch.
 
It was just mentioned to me and I'm just so pi$$ed off I'd try anything at this stage!!
No drag when selecting gears.
When you say rubber bonding on the drive shaft sorry to sound thick but where exactly? Do you mean the Hardy Spicer joints? Does that not just cause shunt?
This only slips under load around 4K rpm, more evident in higher gears.
 
It was just mentioned to me and I'm just so pi$$ed off I'd try anything at this stage!!
No drag when selecting gears.
When you say rubber bonding on the drive shaft sorry to sound thick but where exactly? Do you mean the Hardy Spicer joints? Does that not just cause shunt?
This only slips under load around 4K rpm, more evident in higher gears.

The main drive shaft body is two parts (i'm not talking about the main and separate short section, just the main shaft) bonded together with a rubber type bonding to help damp driveshaft shocks.

mark a line with a thick felt tip on both parts of the body, take the bike out and get it to slip then check if the two lines are still aligned.
 
I know exactly where you mean, I'd looked at that when the shaft was out because it looked like something was being "flung" from the join.
Old clutch was (as far as I could tell) definitely slipping because the day I was bringing it into my workshop, knowing the ball ache task ahead of me I (childishly) went down the road a few hundred yards and came back up, throttle pinned in 5th at about 30mph & 5K rpm!....smell of clutch!

Possibly a stupid question but if it turns out to be slip in the shaft can I weld it together??
Or am I asking for problems doing that?
 
Have you made sure the clutch oil reservoir is not over filled and the lever can move correctly?
Were the crank and gearbox seals changed when the bike was split?
 
Drive shaft has steel and needle roller Hardy Spicers at both ends. The shaft has a rubber shock damper in the middle which might separate but it would surely cause you to have no drive at all.
You can check the clutch for contamination by taking off the starter motor.
BMW engineers live in bubbles so they forgot to design the bike so you could easily remove the clutch inspection cover.
 
The rubber will be there to deal with harmonic vibrations or maybe a shock absorber. Either way welding it up won’t be a good idea.
 
Drive shaft has steel and needle roller Hardy Spicers at both ends. The shaft has a rubber shock damper in the middle which might separate but it would surely cause you to have no drive at all.

Nope. First indications is slipping, same as a clutch. That's why i suggested the drive shaft
It can continue to slip for quite a while unless severely abused, in which case the rubber bonding can melt.
 
I was of the opinion that the symptom of shaft rubber failure, was the bike slips at lower speed, i.e.: pull away from stopped and lower gears rather than acceleration in higher gears associated with clutch wear/contamination?

But that my belief.:beerjug:
 
Clutch fluid centre of the view port, gearbox output shaft seal only leaking seal, but was done.
Clutch friction disc that was fitted is a Kevlar oil and heat resistant unit.
Absolutely no drag from the clutch, lever position perfect and lever feel is ok too.
I'm leaning towardsslip in the drive shaft like Steptoe said, few posts on 1100RS owners site about it too, symptoms very similar to mine i.e. slip seems to start to happen just over 4K rpm which is allegedly peak torque.
Not breaking the drive down again so soon but will pull back the gaiter boot and do like Steptoe said: alignment marks on both components and go for a short drive and chec alignment again.
 


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