clutch slipping!

[motorolo]

hi there!
i just picked up an 1973 r75/5 with clutch problems.
when the bike is cold, the bike will rev without moving the bike.
after a few minutes, it'll engage again without any problems. Seems
like it works better when the bike is warm. anyone have any ideas
on what the problem might be? how hard will it be for a beginner to
take apart the clutch? sounds expensive...is it a good idea to find a
used replacement, or should i just bite the bullet and buy new clutch guts?
lastly, which to go with: clymer or the haynes manual?
thanks!
-rolando

[20774]

New-to-you bike probably means you're going to need to dig inside this and figure out what's wrong. As for manuals...yes...you should probably get both as they offer pros and cons. You can play one off the other and see what makes sense. They both have errors in them...and good stuff, too.

Things to check:

- adjust the clutch cable. There's been a recent thread where the adjust procedure was posted.

- you might just need a lube of the input splines to the tranny. The clutch splined disk runs on this input shaft...the disk could be hanging up on this because it dry or doesn't slide well.

- could be a worn out clutch.

- could be leaking gear oil from the transmission input seal or engine oil from the rear main seal.

Try the cable adjustment. After that, you should probably plan on pulling the tranny and making some assessment. You'll need a few special tools, but the ability is rated at about 3 wrenches out of 5. Better yet, find some local Airheads who've done this before and have them watch over your shoulder. You'll just need to provide something to quaff themselves with and something to eat...it'll be done in no time!

[44006]

Confirm that the lever on the back of the transmission that actuates
the clutch is not adjusted so that it is so far back that it touches
the frame crossmember - some folks faced with a stranded cable or
cable with collapsed casing will keep screwing the adjuster at the back
of the trans in until the lever is back against the frame and then even
though there is some freeplay at the handlebar lever the clutch will
slip because the lever on the transmission has no freeplay.

[rogermansfield]

Read further in this forum my posting about "clutch whine". There are some notes and websites that will help. Adjusting the clutch is easy.

[mmmalmberg]

There are others here more expert in this than I but until they chime in... I would first check the shaft that runs from the clutch lever on the back of the tranny and make sure it's not sticking. And that your clutch cable's OK. After than I'd be looking at the splines, which are likely to need lubed in any case. You may not need any parts at all...

[mmmalmberg]

Sorry, did not mean to infer lack of expertise on the part of prior posters! Really just meant that I'll throw my two cents in regardless thereof.

[gertiektn]

Maybe it is a tranny engagement problem. "Not going while cold????" This may be related to the throw-out bearing and associated assemblies. Make sure you are going into gear first. I have experienced a sticky 1st gear and am suspect of the tranny shifter mechanism.

Anybody have any thing to add to this. Comments welcome.:bikes

[skiteach]

Seems to me that the trans/clutch activation parts are most likely the issue. A worn disk is going to slip all the time and I seem to remember that an oily disk grabs slightly better when cold. Wonder if input splines are sticking or worn?

[rogermansfield]

I seem to remember an old BMW mechanic telling me that you know the splines need lube when the clutch sticks.