999 Clutch Stack Height And Plate Count

Ime, thats likely to be the new plates binding in the basket slots as the clutch warms up.
Cure is to put some of the old worn plates back in at the top of the stack to allow the clutch to clear.
Once the new plates at the bottom have run in a bit, you can put them at the top and your not run in ones at the bottom.

 

How do top plate tangs look sitting in the basket slots? Are they flush or “under flush” and by how much?

 

1) the springs in your pictures look almost coil bound..

2) Flat metal plates of different thickness are interchangeable. The idea is to create and maintain the 38.5 mm new stack height as the friction material wears off and reduces the thickness of each plate. The higher the stack height, the more the springs are compressed, and the greater the force pushing the plates together. The clutch slips when there's not enough force supplied by the springs or the friction material is worn completely off. The action of slipper clutches is tuned by varying the stack height.

The flat metal plates come in stock 2.0, 2.5 or 3 mm thicknesses. When the overall plate stack height wears say 0.5 mm, replace one 2.5 mm flat plate with a 3 mm one. At 1 mm stack height wear, repeat for a second flat plate. At 1.4 mm–.6 mm wear, replace all the friction plates. Allowable friction plate wear is 0.2 mm (each).

There are a number of equivalent stacking methods:


748, 916, 996 (From the Haynes Manual)
7 friction plates
1 convex plate

2.0 mm flat plate
2.0 mm flat plate
3.0 mm friction plate
1.5 mm convex plate (convex side facing outwards)
3.0 mm friction plate
2.0 mm flat plate
3.0 mm friction plate
2.0 mm flat plate
3.0 mm friction plate
2.0 mm flat plate
3.0 mm friction plate
2.0 mm flat plate
3.0 mm friction plate
2.0 mm flat plate
3.0 mm friction plate
2.0 mm flat plate
pressure plate (line up marks)
38.5 mm Total

916SP, 916SPS, 996S, 996SPS
8 (thinner) friction plates
2 convex plates

2.0 mm flat plate
1.5 mm convex plate (convex side facing outwards)
2.5 mm friction plate
1.5 mm flat plate
2.5 mm friction plate
2.0 mm flat plate
2.5 mm friction plate
2.0 mm flat plate
2.5 mm friction plate
2.0 mm flat plate
2.5 mm friction plate
2.0 mm flat plate
2.5 mm friction plate
2.0 mm flat plate
2.5 mm friction plate
1.5 mm flat plate
2.5 mm friction plate
1.5 mm convex plate (convex side facing inwards)
pressure plate (line up marks)
38 mm Total

998 (From the Ducati Service Manual)
6 friction plates
1 convex plate

2.0 mm flat plate
1.5 mm convex plate (convex side facing outwards)
2.5 mm flat plate
1.5 mm flat plate
3.0 mm friction plate
2.0 mm flat plate
3.0 mm friction plate
2.0 mm flat plate
3.0 mm friction plate
2.0 mm flat plate
3.0 mm friction plate
2.0 mm flat plate
3.0 mm friction plate
2.0 mm flat plate
3.0 mm friction plate
1.5 mm flat plate
2.5 mm flat plate
1.5 mm convex plate (convex side facing outwards)
pressure plate (line up marks)
38 mm Total

Difficulty finding neutral is a result of an inadequate separation of the plates caused by air in the hydraulic line and/or installation of a too large diameter aftermarket slave cylinder.

 

Coil bound means the springs are fully compressed and touching each other...

 

so when you squeeze the clutch in there isn t enough gap in the coils to get the full movement for disengaging.

Are they new springs, what about the height of the spring caps too ie how tight did you have to turn the cap screws in before the caps bottomed out...

both of these would restrict the amount of disengaging you are getting with the clutch........or of course the clutch pack height is too tall...

 

but thanks for your help anyway.......

 

@Lucazade assuming it is a non slipper clutch: have you fitted the pressure plate correctly so that the teeth engage correctly on the drum? That may explain the coil bound springs that @andyb kindly pointed out.
On a standard plate, one needs to line up the cast triangle on the plate with the spring post with a notch.

 

Severe drag can also be caused by new (aftermarket?) friction plate tangs binding in the basket slots as they expand with the engine warming up.
Symptoms for this are clutch works fine at start up with a cool engine but suffers increasingly from drag as the motor warms up.
Have we established if this a slipper or conventional clutch? Pressure plate looks unusual...

 

we have established ive lost the will..does that help?

 

Hope you find it soon yet to write mine.

 

That's not a slipper.

 

Do I get a prize?