I am helping a friend with a clutch slipping problem on an ES2.
It slips on hills well before full throttle, and when accelerating to overtake.
Also, the handlebar lever is stiff - needs a lot of force.
We pulled it apart; there was oil in the case - I don't know what type, and not very much - it was well below the drain/oil level hole. The pushrod had ample slack.
The plates were deep inside the basket - either plates missing, or non-standard thin plates.
There are 4 steel plates (dimpled, see photo) and 4 double sided fibre plates, plus one single sided fibre plate (the outer plate).
The bike had stood for a number of years before he bought it, and I think rust damage can be seen on the steel plates.
The fibre plates seem to have fibre pieces (all rectangular) bonded on.
The steel plates are 2.3mm thick, and the overall thickness of the fibre plates are 4.2 mm thick, the metal plate on which the fibre is bonded is 1.9 thick. So the fibre pieces protrude only 1.15mm above the metal face.
I don't have any parts to compare this data with, but I think the metal plates need replacing, and the fibre plates are too thin.
Screwing the spring nuts further in resulted in the clutch handlebar lever being almost impossible to pull in.
Can anyone help me with suggestions?
Hi Richard; if the plates…
- Log in to post comments
The four double sided…
The four double sided friction plates should be around 4.5mm & the single sided one 2.8mm. Also the backplate needs to be in good condition. I had this problem on my 650ss years ago. The plates all looked to be fine, but the clutch slipped, so I replaced the five friction plates & end plate but it still slipped. Next I replaced the back plate & all was well. It has never slipped or dragged since.
- Log in to post comments
Thank you for your comments.
I have found now that the steel plates are warped and as the photo shows, have rusted areas (directly under the fibre while standing for years). These rusted areas are slightly raised, so we've decided new steel plates are required.
The pushrod moves easily so no problem there.
Thank you again for your help.
I'll post the results of the change.
- Log in to post comments
Clutches are a much abused…
Clutches are a much abused and bodged item. It would help to know what year bike and if an AMC box or earlier `laydown etc. Its not helped that clutch types are swapped about and also plates and springs mixed up. Suppliers dont always know whats right either. What you have shown are AMC type parts ,but they also come with different thickness plates, spring strengths and pressure plate thicknesses dependant on power of engines. Add in wrong leverage ratio bar levers ,normal wear and tear, bad cables and incorrect adjustments and you have a perfect mixture for mayhem. The recently published books by the club ,service notes etc are helpfull .
- Log in to post comments
Hullo Robert..
... for responding to our problem.
It is a 1962 ES2 with an AMC box.
I do think that the problem is a mix of incorrect old and worn out parts.
As I said earlier, the plain plates are warped and touch the fibre at either the top or bottom.
So a lot of friction area is lost. The rust damage doesn't help.
Also, it is correct that the inner tangs/dogs on the fibre plates have been filed, probably not enough. We'll certainly correct that.
I'll look at the service notes.
Thank you again.
- Log in to post comments
Hi Richard; if the plates have not been prepared since removal I would say they look in usable condition. They seem to be modified items from another vehicle as the tangs have been filed. There seems to be a witness mark on some of the tangs where they may be tight on the drum. Not modified enough,
How does release mechanism work without the clutch plates in place? Is the rod free in the shaft, does the lever and actuator move freely? If so you know it's down to the clutch rather than the release mechanism.
Check the plates are not warped, tidy up the tangs and fit them in to see they have good clearance and move freely. The drum can get notches worn into it where the plate tangs are transferring load, smooth any ridges out with a stone.
if above fails ensure the clutch basket is sat on the shaft splines correctly and is not moving when you apply release pressure.
Cheers
Jon