1100 clutch premature death and suspicions.

[Tsiklonaut]

Not my bike. Currently replacing mate's 1999 R1100GS'es clutch that got slippy when we returned from Syria/Jordan and in Greece, where we rode around 140-160kph (90-100mph) speeds on the mountain roads going on full throttle (bikes were fully loaded) on the steep climes or accelerating out of curves he noticed a clutch slip.

Also later the clutch stared to make noises (a "loose" pressure spring coz of no counterpressure from the worn clutch disc?) as it wore out more. It got worse by the day, but his trusty 1100 still got him home over 2000km away, safely.

He's bike is at 60Kkm (40K miles), so I reckon it's a premature death for the oilhead clutch(?)

One of the suspicions - see the oil marks on the clutch plate going out. First we thought is was a grease from the shaft's teeth, but it was too viscous for the grease.

Another pic of the suspected small oil appearance on the clutch plates.

The pressure spring looked OK.

Except that spot, looks like something has dragged it, but it turned out to be a grease.

Clutch plate, any more aknowledged guys can rate the colour of the material? Is it soaked with oil or is it OK?

...until we spotted this! We put the gearbox on the ground with a small angle leaning forward and a gulp of TRANSMISSION OIL came out of the input shaft's hole (where the clutch rod operates).

The very suspicious oily input shaft...

MOST of the transmission oil was "trapped" on the other side of the input shaft, into the clutch arm's rubber sleeve.

Very oily sleeve - the smell was unmistakable - transmission oil!

So this is our current theory - the leak is from the input shafts other end's taper roller bearing race. Anyone can confirm?

Another pic...


Looks like a very rare problem? I have heard engine's output shaft blowing up causing a oily-slippy clutch. But oil coming from transmission side seems to be a very rare case(?)

With engine oil leaks through output seal, it's usually excessive and you would see the oil marks on the clutch casing etc.

Ours was relatively clean, but some spots were oily and I reckon few drops of the transmission oil on the clutch plate was enough to make it slippy.

The oil leak from the transmission side apparently is very small and slow. There was just a small (but serious) gulp of oil in the clutch arm's sleeve.

So the main question is: how to make the leak stop? Apparently there is no seal on the other end of the gearbox'es input shaft. It's just a taper roller bearing capped with race from the other end. The race is supposed to work as a seal? If so, looks like the only way to replace the bearing race is to completely open the gearbox(?)

What do you tech guys reckon?

Thanks in advance, Margus

 

[DrFarkoff]

MArcus is there a "step" machined in the clutch pushrod? or is it smooth and the same diameter it's full length?

Later ones had a Felt seal one the clutch pushrod but I can't find it on the microfiche

Is it possible that your friend changed the gear oil whilst on the sidestand? I had this with a 1200C that someone had done that on there was one and a half times the amount of oil there should have been in there!

 

[kompost]

I don't want to worry you but this is exactly the same as my mates 1100 that i sorted for him a while ago.
His clutch was slipping ,so i stripped it and it looked the same as yours ,the oil was running down the pushrod the same.
He also had a clunk from the gearbox when setting off in first.
It turned out to be the collets that hold the bearing on the input shaft had broken up and wrecked the seal at the rear of the input shaft.
I had to strip the box and replace the input shaft ,bearings and seals ,and also did a mod to the wavy washer on the input shaft (search on here for "update on 1100 gearbox clunk")
His was an m97 box and it had a seal in the rear ,i think they all do ,what box is yours?
I tried to save him a bit of money by just replacing the oil soaked friction plate ,but had to strip it again because it still slipped ,it turned out that the pressure plate and cover plate had worn dished ,check this with a straight edge across the plates. I think it is worth just getting a complete new clutch kit ,it will save a lot of work in the long run. Your plate does look oil soaked from the pics.
Good luck.
kompost

 

[Dragon Master]

Hi Margus,
Hmm... this looks suspiciously familiar, but not quite as drastic as my situation. I fitted a replacement box on mine last October, to replace one that needs the wave washer mod doing. All seemed fine until I went off to Paris for a day trip. I( did get a slight amount of slip on the French M-way, and decided to investigate when I got home; I thought it might just be that I hadn't set the clutch properly.

However, I didn't get home, well at least not under my own steam. One the way back to Calais I pulled in to a service station, and was greated by vast clouds of grey smoke from the exhaust; most of the transmission oil had exited the box on to the cat.

When I had a look it seems that the oil had made its escape via the back end of the input shaft; there was a nice shiny channel washed through all the crap plastered to the casing, just below the shaft. And when I removed the clutch push-rod it had a nice shiny coating of oil.

Seems the oil seal has blown. Mine is a '99 box, but I believe all those from '97 on have roller bearings and an oil seal, rather than the tapered roller bearings. See the thread :

http://www.ukgser.com/forums/showthread.php?t=132916

I think it's explained in that.
Unfortunately it seems that the seal in question is the only one that can't be replaced from the outside, but as you've already got the box off, that shouldn't be much more of a problem.
I'd be interested to know what you find; I'm not touching that box yet, I'm going to do the wave washer fix on the old ('97) box, and put that back on.

Cheers,

Dave.

 

[Tsiklonaut]

Thanks guys, lot of good input here.

We've decided to open the box up and inspect inside, to pinpoint the probs out and see what needs fixing.

After it's put together again, will let you know if it blows up or not

Cheers, Margus

 

[Tsiklonaut]

Box open - all looks fine from inside, no excessive wear or dent marks etc. The drain plug magnet showed normal metal-dust, the same amount and granularity when I change oil on every 6000miles on my 1998 bike (same M97 box) to inspect the magnet - looks like a normal wear to me.

So currently it looks like it's a bad seal on the other end of the input shaft. That leaked just few drops per very long distance, and was enough to kill the clutch.

So we'll have to remove all 3 shafts from the gearbox to access the input shaft's other end bearing with seal.