Vintage BMW Motorcycle Owners

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.

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?

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.

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

thanks for the tips, much appreciated!