Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > Clutch Pressure Plate Movement

[r15suk]

Originally Posted by dunlop0_1

The hydraulic movement of the push-rod/cylinder should not alter as it is fixed. If anything wear or air in the system would create less movement. Sounds more like the stack is incorrect/rusty/dirty or has too many plates. Possible drum issue so It really needs a complete strip down.

Stack height is correct as spec 38mm (Haynes) and its quite new. The issue only came about when I fitted a lever with a greater span adjustment and could pull it back to the bar further. This translated into more clutch movement and off popped the plate. I have an Oberon slave fitted so maybe this allows more piston movement and hence more rod movement..

[skidlids]

what clutch spring caps do you have

[r15suk]

Originally Posted by skidlids

what clutch spring caps do you have

After market ones, but I'm not sure of the make. Can this make a difference?

cheers
Simon

[antonye]

If you've still got your originals it's worth comparing them to make sure they're the same depth. The 1098 and Hypermotard (and probably others) have different depth spring caps to change the clutch setup so you may have the wrong ones.

[r15suk]

Originally Posted by antonye

If you've still got your originals it's worth comparing them to make sure they're the same depth. The 1098 and Hypermotard (and probably others) have different depth spring caps to change the clutch setup so you may have the wrong ones.

Thanks for that, i'll see if I still have them.

Cheers
Simon

[dunlop0_1]

Originally Posted by r15suk

Stack height is correct as spec 38mm (Haynes) and its quite new. The issue only came about when I fitted a lever with a greater span adjustment and could pull it back to the bar further. This translated into more clutch movement and off popped the plate. I have an Oberon slave fitted so maybe this allows more piston movement and hence more rod movement..

I think you have answered your own question.

[r15suk]

Possibly have answered my own question, but I have never heard of fitting an Oberon to cause this issue?!? I chucked my old slave away so I can't swap it over to try. I can borrow one but its from a later model and I have heard that they are different in some way?

Simon

[antonye]

The problem is that there are a lot of variables at play, and any one, or combination of them, could be causing the issue:

Master cylinder push-rod adjustment (adjusts initial push point)
Master cylinder span adjuster (allows more fluid to push)
Slave cylinder piston size (defines how much fluid flows with lever travel)
Clutch stack height (defines biting point, resistance, etc)
Clutch pressure plate (defines spring height/preload)
Springs (defines preload, resistance, etc)
Spring caps (defines preload, spring height, etc)

then you have things like wear and tear - clutch friction material, basket tangs, inner hub wear, springs going out of spec, air/water in fluid, etc!

Changing a few of these at once can sometimes make a small problem in each into one big problem, so you're better off reversing as many changes as possible and adding bits one at a time.

For the clutch slave, later ones (recessed star pattern) will work fine with early bikes anyway.

[r15suk]

Originally Posted by antonye

The problem is that there are a lot of variables at play, and any one, or combination of them, could be causing the issue:

Master cylinder push-rod adjustment (adjusts initial push point)
Master cylinder span adjuster (allows more fluid to push)
Slave cylinder piston size (defines how much fluid flows with lever travel)
Clutch stack height (defines biting point, resistance, etc)
Clutch pressure plate (defines spring height/preload)
Springs (defines preload, resistance, etc)
Spring caps (defines preload, spring height, etc)

then you have things like wear and tear - clutch friction material, basket tangs, inner hub wear, springs going out of spec, air/water in fluid, etc!

Changing a few of these at once can sometimes make a small problem in each into one big problem, so you're better off reversing as many changes as possible and adding bits one at a time.

For the clutch slave, later ones (recessed star pattern) will work fine with early bikes anyway.

Thanks for this info.

My clutch plates are only about 600 miles old and the stack height is correct, so I know i'm all right there.

I put the old lever back and made sure the push rod adjustment was correct and the issue was still there so I know it's not that.

As you suggest I will try and do it one step at a time.

Cheers
Simon