He guys (and girls?),

I need some help again with the clutch. In July my clutch gave up. After examening the clutch it self looked to have no problem and the slave cylinder wasn't leaking so it had to be a worn out master clutch cylinder. After a revision kit (thanks to paso750 and Nicola's tips) the hydraulics work again. However no clutch function.

Time to remove the control disk, springs and disks to see what is the problem. I soon found out. In the photo in the following link you see the clutch control disk and the press pin which should push it



For you're info the control disk (part nr. 066516690 in the parts cataloque) sits on the pressure plates and holds the springs in place via 6 bolts. See picture.



It looks like a part of the push pin is broken of (disk shape?). When looking at the following pics you see the brittle break area's were something was and the cavity/socket in the control disk were I think that part is falling in to.





Because the press pin now goes through the pressure plate there is no decoupling and a small metal rim on the plate is completely pushed backwards see pic.



Having explained the problem I'm now trying to find out how the parts looked before they were damaged. Are it two seperate parts or are they connected and which part is missing. Although I have an original workshop manual I can't get a clear picture (also not on the web). Could someone provide me with some pictures or a sketch how the part has to look, preverably with dimensions so I can rebuild, make or order new parts.

I guess this is the charme of an almost classic bike.

greetz,

Remko Spenkelink (Paso144).

Thanks for the reaktion. Actually the part in the piston looks about the same but is still there in the cover. It indeed looks like the pin on the photo was connected to the disk by a weld.

A second inspection showed that the cavity on the disk could also be a worn out piece.

A picture of the original lay-out would be great. I don't know if it was original before I opened the clutch. Maybe the previous owner did some faulty assembly/welding.

greetz Remko

Remko,

I have only the parts list drawing that you have posted in your first post.



I don't see the pin you are saying comes from the disc. I was thinking that you were referring to the pin/button in the slave.

Some more info here: http://desmodromico.com/sito2/attuatore%20integrato.htm

I don't have my clutch or a picture handy. Maybe Gerhard has one??

He Jon,

I checked my workplace manual and there the pin is visible but not a way I can work from the picture. I'll take a picture of it. The part manual I took from the site.

Maybe it's different between the old 750 paso's and the newer ones. Mine is nr. 144 from the line so it is probably produced in '86. I saw in you're mail you also own quite an old version '87. I don't know if they made changed through the 750 series or that they saved that for the 906's.

Newer Ducati's have a more common clutch approach with an hollow axle and the engagement from the other side of the motor iso the slave cylinder in the clutch cover, hence all those nice open cover which give the typical ratling sound.

greetz Remko

By the way could you give me a short description on how to paste pictures in the postings (the guideline on the site isn't very clear).

He guys,

Thanks for all the info. I added a picture from my own work shop manual in which you can see a clear difference between my control plate with the pin and the plate from the parts manual with only a hole (picture in Jon's reply).


Can anyone of you guys tell me what the distance between the front face of the pin and the front face of the rest of the plate must be so I can do some welding. The welding could be done by a mate of mine who is a highly skilled professional welder that welds wafestepper equipment, so he should be able to fix it needly.

For you're interest I added a photo of the inside of the clutch cover and a work in progress picture. When I still have the plates out of the clutch it's worth checking them on wear.





regards,

Remko
[/list]

You probably want it about 1mm away from the slave cylinder button, although I don't know this for a fact!

I would block off the hole in the plate with a sheet of metal taped into place and then reassemble the clutch. Place some stiff putty on the sheet metal attached to the plate and mount the clutch cover. Then measure the thickness of the putty when you remove the cover. This will give you the total clearance and will allow you to place the welded pin at the right spot.

I don't think we have gotten to the root cause of the failure though. What caused this pin to wear thru?? If the clutch slave pin is loose and rotating in the slave (this must be checked carefully) and this pin is firmly attached to the plate. What caused the failure??