Input shaft/pressure plate contact?

[baffle]

Don't know if any work done on transmission and 12 previous owners. My input shaft is 180.93mm long. Any comparison dimensions? The diameter for the push rod is 8.57mm at piston end and 9mm at clutch end.

[georgesgiralt]

Armen,
I don't get the disk not being centered ?
The clutch disk goes on spines with very few play on the gearbox input shaft, and the gearbox body is centered on the engine body. so I doubt you can mount the whole if the disk is not centered properly in it's mechanism.

[Armen]

There is enough slop in the trans mounting holes to allow the trans to mount up even if the clutch disc isn't perfectly centered. When I'm doing a clutch job, I always put an allen wrench in the alternator rotor and turn the motor a few times with the trans mounting bolts finger tight. If I goofed and the clutch disc isn't perfectly centered, I can see/feel the trans moving.
-Armen

[donbmw]

The input shaft is about 24 mm long on the early transmissions, and from 1981, it is about 19 mm long

The above is from Snowbum's site. Will have t assume the length he is given is the splines only. I have a extra trans apart and the input shaft measure the same you have and the splines are 19 mm. I knew the shafts were not the same there just opposit off what I though.

[baffle]

The spline section on mine is 25mm shoulder to end. Has anyone got a loose input shaft from an early transmission and a wernier caliper? Is it impossible that there was a batch of bad machining as my spine section is maybe 1mm too long ( as elsewhere this is reported as 24mm)?  Thanks.

[tvrla]

That pressure plate looks pretty worn out to me. Maybe it's so far recessed the clutch hub was rubbing?

[baffle]

Yes it is worn - 0.5mm ridge maybe. The compression ring also has a similar though less pronounced ridge. The clutch disc is 5mm. Would not the hub rubbing due to wear would be seen commonly? The clearance between shaft and hub must be very tight. Thanks for thoughts.

[baffle]

Just compared shaft with 2 others at Phil Hawksley's. Any differences minimal. Must be clutch - will look to renew the clutch fully. Thanks for all responses.

[tvrla]

With wear like that to the pressure plates, my assumption is the clutch disc was replaced last time, but not the plates. With new plates you could probably continue with the same clutch disc - it's only half worn. But that's a tough one to justify when everything else is new. Besides, clutch discs tend to wear unevenly - more on the outer edge than at the center.

[donbmw]

I started my annual servicing of my R90 last night. Pulled the transmission and looked up throught the clutch splines and did not see any wear on my pressure plate the you have in you pictures. The input splines sticking out of the trans are 24MM. I have replace the clutch disc a few times and have had the throw out bearing go but was able to still use the pressure plate that came with my bike.

Don

[baffle]

Thanks for thoughts. New clutch for a 78-80 R65 is big cost now - just had a quote - £372 for all the bits from one of the UK suppliers (that's $567 for you guys), with pressure ring twice cost of one for later R65s. Is a cheapskate option to get ring and plate faced, and get a friction disc made up a bit over thickness - there is a specialist clutch and brake re-lining unit near me, who might be able to do it, but perhaps I am just playing with fire, and putting off the inevitable.

[Bob_Roller]

I had the clutch disc relined, and both the pressure plate and pressure ring trued up .

The shop did a horrible machining job on the plates, I should have left them alone .

If by chance you so go this route, the first problem that may arise, is that you can't get the cable adjusted correctly, the adjustment bolt at the back of the transmission will be in all the way and you still don't have the proper adjustment .

You need to get a longer bolt, but at the same time, too long of a bolt won't fit the clearance you have between the clutch arm and the swing arm .

You may need to remove the clutch arm from the back of the transmission get the bolt threaded into the arm and then reinstall the arm on the transmission .