Weird clutch

[Worty]

Got around 80m out on my 'sun run' when the clutch lever started doing some odd things   Initially, the lever went from normal to very slack (locknut was fine).   I tightened it on the lever, but it felt a bit 'spongy' but still worked.  As I was riding back, it got tighter on the lever to the point I was concerned it'd make the clutch slip, so slackened it off.  This happened on and off all the way back home.  Only at one point did I have to stop and adjust again when at a set of lights it went slack and I couldn't get to neutral.

Any ideas before I start pulling it apart??

Cheers

[Topdad]

sure this happened to me a good few yrs ago, clutch locknut on centre loosened  but hang on for a few more responces

[Worty]

sure this happened to me a good few yrs ago, clutch locknut on centre loosened  but hang on for a few more responces

If it is, next time I'm going to locktite it up as it was properly tight when I put it on (locking tab was in place properly too).  It did manage another 70m back home without a problem though??

[KiwiGF]

Got around 80m out on my 'sun run' when the clutch lever started doing some odd things   Initially, the lever went from normal to very slack (locknut was fine).   I tightened it on the lever, but it felt a bit 'spongy' but still worked.  As I was riding back, it got tighter on the lever to the point I was concerned it'd make the clutch slip, so slackened it off.  This happened on and off all the way back home.  Only at one point did I have to stop and adjust again when at a set of lights it went slack and I couldn't get to neutral.

Any ideas before I start pulling it apart??

Cheers

Give it the benefit of doubt, when the clutch gets hot (eg in trafijc) yes the slack increases, conversely when it cools the slack reduces. Not sure why its just the way they behave, it’s not normally an issue, but if it is “excessive” something is wrong maybe plates sticking in the basket 

[Worty]

I know what you mean, and this happens normally, but this isn't normal.  Clutch isn't nice and crisp, something is amiss.  I'll start by checking the gearbox lever and pushrod before the primary comes off.  

[Swarfcut]

Possible prelude to a failing clutch cable. If the barrel nipple in the handlebar lever sticks, the cable will flex at the nipple, strands fail and the cable eventually breaks. A spare clutch cable in the toolbox saves a nightmare ride home with pushing,  jumping on and kicking it into gear at every stop.

 Been there, done that, winter, in the rain, at night. 

 Swarfy.

[Worty]

Possible prelude to a failing clutch cable. If the barrel nipple in the handlebar lever sticks, the cable will flex at the nipple, strands fail and the cable eventually breaks. A spare clutch cable in the toolbox saves a nightmare ride home with pushing,  jumping on and kicking it into gear at every stop.

 Been there, done that, winter, in the rain, at night. 

 Swarfy.

Will double check Swarfy, but a cursory inspection sees the cable in decent nick.  When I removed the gearbox inspection cover, the lever seems to go too far in as if the pushrod is further in than it should be.  The pushrod itself seems fine, so I'm suspecting the clutch itself is playing up.  Over 900 miles since the rebuild, and it's been fine - also got me back home fine despite the issues.  Looks like I'll have to have the primary cover off to see what's going on (boo, hiss).

[chaterlea25]

Hi Worry,
I wonder had a similar issue,
It turned out to be a plain clutch plate distorting into the shape of a Belleville washer, sometimes slack clutch then it would come right as the plate flattened out repeat performance come the next stop- start 

John

[Worty]

Hi Worry,
I wonder had a similar issue,
It turned out to be a plain clutch plate distorting into the shape of a Belleville washer, sometimes slack clutch then it would come right as the plate flattened out repeat performance come the next stop- start 

John

Cheers John, looks like that may well be my issue.  No idea how old the plates are exactly, but it's donkey's years.  Time for a clutch strip down to see what's going on mate.  Lever definitely feels spongy, which would also fit with what you're saying.

[Slymo]

Pull it apart. There is no way an issue like that is going to go away without potential reoccurrence and the next time it might involve damage. A similar thing happened to a mate of mine on his early Panther 600 and it was a broken roller from the primary chain getting into the clutch basket. He got away with it but the next step could have been a whole lot worse.

[Worty]

Pull it apart. There is no way an issue like that is going to go away without potential reoccurrence and the next time it might involve damage. A similar thing happened to a mate of mine on his early Panther 600 and it was a broken roller from the primary chain getting into the clutch basket. He got away with it but the next step could have been a whole lot worse.

Yikes, stripdown

[Worty]

Ok, stripped clutch down today and found the shaft nut was loose after all.   The thing that bothers me is that it seems to have loosened quite a bit against the locking washer.  When I released the locking washer, the nut tightened up a lot (a few turns at least).  Can't see how this could happen unless it's been forced round, but the washer doesn't look as if it's moved.   Think I'll reassemble with some Loctite on the thread and see what happens (it was belted up tight originally). 

Couple of things though:

1.  Is it worth replacing the roller bearings - they seem ok but no idea how old?
2.  As in the picture of the clutch centre below, what are the internal threads for??
3.  Because all the oil had wet sumped, I managed to drain most of the engine oil through the primary screw holes.
4.  Primary chain has some tight links - time to replace I reckon (only done around 12,000 miles though).
5.  Any tips/ideas on why the nut loosened - has happened before.  Does clutch centre need to be tighter on the taper?

Checked crank for movement Bergs, tiniest amount of endfloat, but not visible and nothing like before (no up and down movement though).  Gearbox mainshaft has a little bit of up and down - can't remember if this was a RM special or not.

Comments and advice always appreciated fellas.

[Catz]

The internal threads are for the attachment of a puller so you can get the clutch centre off the shaft.
I think i torqued mine up to about 70nM.

[Triton Thrasher]

Tab washers aren’t very good in this application.  Loctite is needed.

[Worty]

The internal threads are for the attachment of a puller so you can get the clutch centre off the shaft.
I think i torqued mine up to about 70nM.

Ah, yes, of course - never needed a puller on mine, maybe the taper's a bit duff.  I'll try 70Nm with Loctite I reckon.