need advise with clutch maintenance

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wolds
Posts: 106
Joined: Mon Nov 08, 2010 1:18 pm

need advise with clutch maintenance

Post by wolds »

Hello,

I'm doing some preventive maintenance and have the clutch out of the bike. I've measured the relaxed height of the diaphragm and it measures 17mm. I believe the spec to be 19mm. Is this spec correct and if so do you think I should replace the diaphragm? Clutch operation seems to be normal with no slipping. I have it apart to grease the input spline and for swing arm bearing inspection. Any advise would be appreciated.
2007 BMW R1200RT
1979 Yamaha XS650 "cafe"
1976 BMW R90S
1976 BMW R60/6

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schrader7032
Posts: 7460
Joined: Fri Oct 27, 2006 3:00 am
Location: San Antonio, TX

Re: need advise with clutch maintenance

Post by schrader7032 »

My Haynes doesn't show the R90S but shows all /6 models as around 19mm. If it were me, I'd replace it. How many miles? Why not replace everything if you're there?
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

wolds
Posts: 106
Joined: Mon Nov 08, 2010 1:18 pm

Re: need advise with clutch maintenance

Post by wolds »

bike has 41K on it and I believe the friction disk has been replaced as it measures 6mm. The rest of the clutch looks good with very minimal hot spots so I'm going to clean everything up and re use. I'm looking at the diaphragm that boxer 2 valve sells and was going to call him Monday to bounce my situation off him and see what he thinks.
2007 BMW R1200RT
1979 Yamaha XS650 "cafe"
1976 BMW R90S
1976 BMW R60/6

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RickR90s
Posts: 86
Joined: Mon Nov 28, 2016 4:54 pm

Re: need advise with clutch maintenance

Post by RickR90s »

Its a $60 part and is measured less than spec so it would be smart to replace it. Be sure to check for signs of a leaking rear main seal, oil pump cover and trans input seal while you're in there. A slipping clutch on a long trip isn't any fun.

You probably already know this, but you only want to apply grease to the spline itself, never the friction disc splines. (to prevent the grease from flinging off and getting on the disc)

RickR90s
Last edited by RickR90s on Tue Feb 23, 2021 11:21 am, edited 1 time in total.
RickR90s

wolds
Posts: 106
Joined: Mon Nov 08, 2010 1:18 pm

Re: need advise with clutch maintenance

Post by wolds »

thanks for the tips, much appreciated!
2007 BMW R1200RT
1979 Yamaha XS650 "cafe"
1976 BMW R90S
1976 BMW R60/6

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