Clutch Plate Installation Issue

The noise from the clutch of my 2002 M900ie has become a bit annoying, I'm a lover of the Ducati clutch rattle symphony but mine as become excessive, so I decided to have a look at the clutch & see if the plates etc were worn. Apart from the noise the clutch works fine.

On taking the clutch apart I found that everything was good except that the friction plates were almost worn out. Steel plates are all good & while there is some minor burring on the basket slots it is very minor indeed, so no problem. I decided to change the friction plates to see if this improved things. This is when the fun started.

I bought & fitted a set of Ferodo clutch plates. The installation was dead easy (all plates in the right order & the dished 1.5mm plate facing the right way). I started the bike, the clutch appeared to be moving nicely on the lever & the noise was back to normal levels, all good except that I can't change gear! I can select first or second from neutral but can't return to neutral or move up the gearbox. I bled the clutch cylinder (twice) but with no improvement. After much head scratching I removed the Ferodo plate & put the old ones back in & guess what everything works fine again.

My question is why don't the new plates work? Are Ferodo plates just rubbish? Do I need to use Ferodo steel plates as well? Or have I missed something obvious?

Any advice would be most welcome. Thanks in advance.

[Luddite]

From memory of my M900 days, I think the recommended stack height for the clutch plates is 38mm +/- 2mm.

If the height exceeds this, then you will experience problems selecting gears as the clutch will not fully disengage. The problem will be more apparent if you also have an aftermarket low effort slave cylinder, as this will transfer less movement to the clutch pushrod.

It may be that the extra 'meat' on the new plates is making the stack height too high. Try measuring the stack with new plates and compare with the height with old plates.

Have you only tried selecting gears at a standstill? You might find you can go up and down the box once you are moving. The problem would improve as the plates wear but that's not much help to you if you can't actually get out of second gear.

[Dukedesmo]

Originally Posted by Luddite

From memory of my M900 days, I think the recommended stack height for the clutch plates is 38mm +/- 2mm.

I believe that is the spec, however I wouldn't go above 38mm or you'll have problems finding neutral.

Thanks Guys, that's really useful.

The slave cylinder is standard. I can engage all gears at a stand still without the engine running but hit problems when the engine is running.

The stack height might be the key to this. The height with the new plates is a touch over 39mm. The old plates measured in at about 36.5mm. I thought the "new stack" was within tolerance but this doesn't appear to be the case.

Would removing a plate from the stack work? If so which one (friction or plain) or doesn't it matter as long as the stack is 38mm? Would substituting a new plate with one of the older ones be a better solution?

[slob]

Originally Posted by Luxexterior

... Would substituting a new plate with one of the older ones be a better solution?

that'd be my favourite choice

make sure the marks on the basket and pressure plate are aligned too

[Mr Gazza]

My approach would be to very gently flatten the face of each side of the friction plates.
If you think of 1mm divided by each face of the friction plates, it's not much.

I think I remember someone on here doing it?

I would tape some abrasive paper onto a flat surface (mdf usually in my case).
Then with even pressure gently rotate each face of each plate on the abrasive, just enough to de-nib the surface and making absolutely sure the plate was flat on the abrasive.

There would be a risk of embedding abrasive particles in the friction material I suppose, so the type of abrasive would be important... I wouldn't use wet-n-dry as the carbarundum does come off that... Maybe a good aluminium oxide paper? About 120 grit?

Anyone tried this?

Thanks. Looks like a plan then.

[Luddite]

As Mr Gazza said, I remember reading on here about someone lightly rubbing down the friction plates and it seemed to work for them.

I've not had to adjust the stack height myself but I believe that the recommended approach is to swap around the plain (driven) plates to get the required height. I think they come in 2.0 and 1.5 mm thicknesses but you'd need some spare plain plates to do that but I think you said you'd replaced only the friction plates, so that's not an option unfortunately.

I guess you could remove a friction plate from the top or bottom of the stack so it's either topped or tailed by two plain plates although maybe that could result in some clutch slip under harsh load?

Perhaps better, as you suggest, to swap one of the old friction plates for a new one for, say, 1,000 miles then, when the stack height has lowered naturally, replace it with the final new friction plate.

Frustrating! ��

[Dukedesmo]

Originally Posted by Luxexterior

The height with the new plates is a touch over 39mm.

I'd be reducing that to no more than 38mm.

Assuming you have the standard setup of 2 plain plates and then alternating plain/friction and ending with a plain then I'd remove one of the first 2 plain plates to give just plain/friction alternating (you must start and end with a plain but I can see no real reason to start with 2 plain?)

Unless you have some 1.5mm plates to substitute with the 2mm? if so you can cut 0.5mm every substitution.

I've just replaced the friction plates in my 916 and the new pack measured exactly 38mm but the test ride showed me I can't get neutral when stopped. Being new it might bed in after a couple of hundred miles? but I'll probably just swap a 2mm with a 1.5mm to get it working properly.

Thanks for all the replies & advice. I think I'm going to try swapping or removing plates as suggested. If this fails I will try to get hold of some 1.5mm plain plates & experiment swapping them with the 2mm ones. If that fails I may have to get the wet & dry out.

[jerry]

I ususally keep a few old steels for mix and match when putting in a new clutch pack as they come in 1.5mm and 2mm and dished or leaving a friction plate out

[Darren69]

Agree with all the above. I found I had too many friction plates (the slipper uses one less I believe anyway and the standard pack I got, had one too many) which gave the same symptoms.
You should be able to turn the clutch centre by hand fairly easily with the clutch lever pulled. There's always a bit of drag but you should still be able to turn it.

[Kato]

Just as a visual referance the correct way to measure stack height