Went to the Dragon Rally this weekend and the clutch is now slipping under hard acceleration in top gear. There is freeplay in the clutch cable and the cable itself is free to move. The bike is '09 and only 23000 miles. I need to check that the mechanic is using 'good' oil for the changes, if not he's in trouble!
Has anyone got experience of changing the clutch plates and which manufacturer did you use. Had a look at prices and might as well change the steel plates as well.
Will it be worth renewing the springs with the heavy duty ones?
I do have a manual and will do the job myself as I'm not trusting the garage now. Before I set off I checked the oil level, it was low and the chain was bar tight despite me telling him to make sure it was 'loose'. Can nobody be trusted these days?
Anyhow any input from you guys as to the plates would be helpful as I will be doing a lot of miles this year.

Cheers Steve

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Cheers I'll get me some bits ordered. I will get a new gasket for that price.
Clutch wasn't grabby or juddery so I suspect the steel plates will be OK.

Cheers Steve

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Just out of interest, did it only start slipping after you (or rather your mechanic) changed the oil?

Not done the clutch on the Z, but done a fair few wet clutches over the years and they’re all fundamentally the same. If it’s slipping then it’ll either by poorly adjusted (no free play), contaminated, swollen or worn plates or weak springs. The thing that raises an eyebrow, is that most of the previous tend to cause slippage to gradually appear and worsen over time, they don’t often suddenly happen. It’s probably worth checking with your man whether he used the “good” oil and not an API “energy conserving” low friction car oil, which is a nightmare for wet clutches, causing slip almost the moment it’s used. Maybe you were just showing off and riding it harder in top at the Dragon so it became apparent?!

One thing worth checking before you start throwing money at a clutch rebuild is the cable. I have come across clutch slip cause by frayed cables before. What happens is the cable will pull smoothly when the lever is squeezed releasing the clutch fully, but won’t return fully because of the fray catching somewhere, either inside the outer, or more usually at either end where the cable emerges. The funny thing is, when this scenario occurs you end up with more free play than normally as the clutch operating arm cannot return fully, so all seems well even though it isn’t. You can't often tell just looking, you need to unhook the cable at both ends and see if it glides smoothly through the outer.

The plates are (as you’ve discovered) relatively cheap, and they’re pretty simple to replace as are the springs, so if you’ve ruled out maladjustment and cable issues, then you may as well replace the lot. Either way, if the plates are contaminated (by low friction additives), swollen (usually from excess heat), worn or the springs have gone west then the only solution is replacement. The rest of the clutch mechanism and basket you can inspect when you disassemble the clutch. I personally wouldn’t bother with HD springs, I’ve used them in the past with no discernible difference other than a stiffer clutch action! Unless you’re running serious horsepower, I’d stick with the stock springs, they’re more than up to the job when in good nick and save your money.

Here’s a couple of other threads that may be of use?

http://www.xt660.com/showthread.php?t=20931

http://www.xt660.com/showthread.php?t=16953

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Cheers for the reply Pete, I've done the usual checks and the cable is free to move so no problem there. I have ordered some new friction plates and will do the job myself.
I only went on roads to the Dragon, no heroic stuff I can assure you, but a fair bit of 'making progress' on the M'ways and pretty well loaded up.
(A shame as I was expecting some snow and just fitted new TKC's)
I'm sure that the mechanic has used crap oil and I will take this issue up with him. New, good oil and filter methinks. I'll keep you posted.

Cheers Steve

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....................so I asked the mechanic "what oil are you using?"

"er sumfin like 20/50 fully synthetic" came the reply.

So there we have the culprit.!

I did order new friction plates, clutch cover gasket, oil filters and got some real good Putoline 10/40 semi synthetic from a mate that sells the stuff. (10l for �40!) enough for more oil changes and my small CB250RS Honda!

Did the job today, easy peasy, except that the manual does not mention to take the brake pedal off (which I did), other than that it was easy. Drain all of the oil as per .
The last friction plate as you go in has a bigger internal diameter and a disc spring sits inside of this. It is an antichatter spring and is clearly marked which way around it goes.
I assembled all of the clutch as it came out but with the new friction plates, new gasket fitted and all tightened up, refit the (now folding!) rear brake lever, then refil with oil and hey presto all good. Went for a blast through to Hull (@130 return) and all is good, no slipping and the engine 'feels' better, cannot quantify but certainly fresher.
Anyhow apart from spilling some oil onto the radiator, job done.
As I got the oil cheap I will probably do another change in a few hundred miles just to make sure all of the 'crap' is out of the system, might appear to be overkill, but lets face it an oil change is probably the cheapest yet most important maintenance that you can do to a bike.

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Good result Steve, and you've got a fresh set of clutch plates that should last a lifetime... Unless some dimwit puts energy conserving car oil in it again!

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