K11 Owners Group

J.R. · Joined: 21 May 2008 Posts: 21 Location: Columbia, MO

I'm replacing my clutch which is slipping due to the rear main engine seal leaking. According to repair manual all clutch parts are re-useable and I only need a friction plate. The dealer however tells me I should replace entire clutch or parts will not match and will cause vibration. Really? Do I spend $100 or $550?
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95 K1100RS
86 R80RT

gpzoduibh · Posted: Wed Jun 10, 2009 6:08 am Post subject:

Morning JR
I have had a few clutch issues in the last while I also had an oil leak causing clutch slippage , however it was the O ring behind the clutch nut that was the problem not the rear main seal , also on here if you search as far as I remember it was only the very early clutch assemblies that were marked for balancing the later ones dont have this issue , if the rear main seal leaks the oil will get flung out into the housing but wont get near the friction plate and pressure plates if the O ring is leaking it will get oil into the friction plate area, if it was me I'd go for a new seal and O ring cause your in that far and a new friction plate I'm also not convinced about the new clutch nut and bolts being required.
Good luck
Bill
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1995 Grinnall Scorpion III(1990 K100 16v motor)
2010 KTM 450 EXC
Moto Guzzi V50 powered hovercraft !
1989 K100RS (8V) special edition
1974 Yamaha DT360
1972 Sanglas 400 T
1980 Yamaha XS110-Watsonian Palma sidecar
1966 Bridgestone 175 dualtwin
1980 BMW R100RS
1979 Bultaco sherpa T 350
1979 Yamaha DT175MX
1990 Honda XR250R

wera32 · Posted: Wed Jun 10, 2009 8:21 am Post subject:

You can replace the friction plate alone. The housing is a balanced assy so be sure to mark it when you take it apart. Worst case, if you forget and it vibrates you'll have to take it apart again and rotate one of the parts. I'd probabaly take the assy and get it balanced before I'd do multiple disassemblies!
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Paul - '93 K11/12RS (sold), 2002 R1100S BCP and '03 RC51 KOG 29

gpzoduibh · Posted: Wed Jun 10, 2009 9:33 am Post subject:

This is a good thread on the clutch balancing issue :

http://k11og.org/forum/viewtopic.php?t=6450&highlight=clutch
_________________
1995 Grinnall Scorpion III(1990 K100 16v motor)
2010 KTM 450 EXC
Moto Guzzi V50 powered hovercraft !
1989 K100RS (8V) special edition
1974 Yamaha DT360
1972 Sanglas 400 T
1980 Yamaha XS110-Watsonian Palma sidecar
1966 Bridgestone 175 dualtwin
1980 BMW R100RS
1979 Bultaco sherpa T 350
1979 Yamaha DT175MX
1990 Honda XR250R

SugarHillCTD · Posted: Wed Jun 10, 2009 9:38 am Post subject:

Paul Glaves did a "Benchwrenching" article on clutch assembly balance in this month's BMW Owner News.
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John & Cathy

'92 K100RS4V Pearl White SOLD
'04 K1200GT
IBA Several-SS1k, BBG, 50CC NYC to S.F.

dave n · Posted: Wed Jun 10, 2009 11:22 am Post subject:

Be sure and clean & reclean & degrease the rest of the clutch assembly.

Glass beading the pressure plate would be a good idea too - gets the old glaze off - scotch brite pads or fine sandpaper would work too.
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Dave Norris KOG 248
1999 Cagiva Gran Canyon
1993 K1100LT w/Hannigan sidecar
2008 Suzuki DR650

Flying Duck · Posted: Wed Jun 10, 2009 11:50 am Post subject:

If you just want to be lazy and degrease the pressure plates then use brake cleaner.
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93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

hfxrzw · Mad Brick Rider Joined: 30 Jan 2009 Posts: 78

There are some reports about the housing parts wearing uneven due to different speeds between inner and outer circumference of the clutchplate to assembly, which should result in the mating surfaces not being straight. Therefore renewal of only the plate could not result in fixing the problems. I have not seen it myself, but it is a persistent comment. Cheers, Rene.

tmoons · Flying Brick Rider Joined: 09 Oct 2008 Posts: 161

I’ve had my clutch apart twice now. (not funny!)

I even had my clutch parts balanced …. They told me there was to little unbalance in the parts to cause the vibrations I felt.
I now have a clutch that has NOW unbalance and still have a buzz.
I talked to various experts and the markings on the clutch are made by the factory during the balancing process.

On the “uneven wear” issue. It is correct that the surfaces are not straight, my new plate came out in the second try, and there where clear markings on the plate showing a heavier wear on the outside. This is not an issue, what happens is that the friction plate wears a little faster in the beginning. in the end (after 100.000 miles or so) it IS a wear item (like brake discs, brake pads, and so one... so if you want to be sure... do it all, if your bike has only 10.000 miles on it...

When you pull the thing apart, mark the various parts with a sharp object (I used a marker pen, washed the ink off with brake cleaner just before installing… DOH) Also mark the position of the last part (the silver coloured disc) in relation to the axle it sits on) .

This should give you enough peace of mind to be sure you do not in a balance problem.

When you order the new parts, they will come in separate boxes and have no markings. (of more markings, as the they put a mark on the heavy point during balancing in the factory)

Just pull the thing apart, mark everything with a sharpy and put is back as it came out.

Flying Duck · Posted: Thu Jun 11, 2009 4:25 am Post subject:

You guys worry about this stuff too much. Just ride.... Beemered

_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

J.R. · Joined: 21 May 2008 Posts: 21 Location: Columbia, MO

Thanks everyone. All of my parts look perfect and show no wear. The only issue was oil contamination so I'm going to try friction plate only, as well as o-ring and rear seal.
I did find some markings ! On the housing cover there is a yellow dot near one of the holes where the pin from housing cover goes. right next to pin retainer hole, a 5mm hole is drilled a few mm deep, evidently for balancing. I assume to make the heavy side lighter. There are small indentions on each side of pin retainer holes, six in all. Only one has been drilled deeper.
On the pressure plate there is a painted purple dot next to a white # 2 near a pin retainer hole. Nothing drilled.
On the housing cover I found no paint, however next to one of the pins there is a 10mm hole drilled a few mm deep which I assume is the heavy side.
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95 K1100RS
86 R80RT

SugarHillCTD · Posted: Thu Jun 11, 2009 9:37 am Post subject:

J.R. · Joined: 21 May 2008 Posts: 21 Location: Columbia, MO

This is my first clutch job but looks simple enough. I'm considering weighing the three cluth parts seperately and then as a unit, the same way you weigh aircraft to determine proper weight and balance. It seems if you place three scales under the three pin locations at the same time, you can determine the heavy side of each part. Then as a unit to achieve the best overall balance. I certainly would not be scared to do some drilling myself to balance a part myself using this method. If it helps I will take some pics of the drilled parts so others can see what to look for.
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95 K1100RS
86 R80RT