Hallo David

There is a hole on the side of the torque tube. You must strip off the exhaust and the heat shield. I also got a bore scope now. So will look first before I take it all out. But I still think it is the Slave. I think it gets hung up on the sleeve that it slides over.

Will keep you posted.

 

Hallo All Aston People.

I took the whole clutch apart. I found the following:


This is where the noise was coming from. The propshaft was rubbing on the release bearing sleeve.
But why only after 6 months. How is it posssible to make the pedal not coming back.

The 2 release bearings are 5mm different in height. Compressed and uncompressed.
look at the different profiles from the faces of the release bearings. Yes the profiles on the pressure plate fingers are also not the same.
the spigot of the spacers fit perfect.
Could the higher release bearing maybe pushing the pressure plate beyond a return so to cause the paddle to stay down. Shall I install the old release Bearing?

 

If you did the twin clutch and have that old bearing in there, you need to ask yourself “why is the single plate clutch bearing still in there?”

That bearing that came off with the issue you have shown, is for the single plate clutch(the original bearing). Also to be rubbing with the shaft means the slave was not mounted flat, seems like someone removed it and didn’t reinstall it correctly. I highly doubt the slave inner sleeve or the shaft bent.

The height different of the 2 slaves is different without the spacer behind it. Velocity has a different spacer that comes with the kit along with new bolts that make the final deck height of the bearing same as stock. So in other words you need the velocity machined spacer with the twin clutch slave AND the fully threaded bolts(which Velocity supplies).

 

The single clutch bearing was NOT in the car. I used it to compare the two.
I needed to determine the problem ans to take pictures for all on the forum to see.
By showing we all learn.

The car is back together and ths clutch is quiet. The rubbing noise is gone. The pedal is even lighter.

Will drive it and keep all informed.

 

Sorry, your post was very misleading and made me think the single clutch slave was in the car and was damaged from grinding. So you found the the part causing an issue but what was the problem that forced the grinding?

Your asking a question about the heights but never mentioned anything about the spacer behind the slave..is the correct one in place for the twin plate clutch slave? And we’re the new bolts used? Also did you install a new twin plate clutch slave or just fit that single clutch slave?

 

Have you managed to sort this thorn out yet?

 

Ok let me start from the beginning.

When I installed the clutch the first time, it was fine, it worked fine.There was this noise after 4 months, I thought it was the release bearing.Then the pedal was staying down. I then stripped the master cylinder out and found nothing wrong. The noise was still there when the car was cold and you do not operate the clutch. When the clutch was operated the tone of the noise would change. If you switch the motor off the grinding sound could be heard, when you operate the clutch.
I then decided to open it up. I only found the slave cylinder sleeve to be worn on the inside, by the prop shaft. With the prop shaft back in the torque tube I measured everything. The slave cylinder was dead centre. The 2 cap screws holding the slave was tight.
The bearings was fine. The run out on the prop shaft front was 0.05mm. 0.0019".
So why did the propshaft touch the slave sleeve on the inside?

I did not remove the clutch pack. I did check the flywheel run out to the engine block, I measured the pressure plate to the flywheel for any differences in height differences.

I then swapped the old slave sleeve with the new one. Building the new release bearing on to the old sleeve housing. I did not want the worn housing. The are the same in dimensions. So old housing with new bearing and bellows. I did replace the bearings on the prop shaft and put the clock gauge back on 0.04mm run out. I then put everything back. Installed the torque tube and slide the prop shaft in. I then bled the slave cylinder. Tester the clutch for release. And the pedal for coming back up. That was fine so I carried on installing the rest.
The car was back on its wheel after 10 hours of work.
Since installation I have driven about 75 km of which half was city.
Everything is quiet and working fine.
I could not see any reason for the pedal sticking and how it was possible for the shaft to touch the sleeve inside. For me it remain a mystery!!!!

 

In your images, the cylinder on the right has a different contour of the top surface as well as the height - looking at some other threads, this must be a V12 slave? Is this intentional? (Irish mentioned a twin plate clutch, so that would make sense to use the different part)
Matt

 

The two release bearings do have different profiles. The reason is that the 2 pressure plates have different fingers(diaphragms)The old(original) pressure plate have rounded fingers

This rounder finger use a flat profile in the release bearing. The V12 or double clutch have flat fingers.
.
So the release bearing has a rounded profile. For the double clutch.
This is to reduce the friction between the release bearing and the fingers.
If both were flat then the friction would be high due to the increased surface area. We must remember that the fingers slide on the release bearing when we apply the clutch.
If both the fingers and the release bearing would be rounded and the contact area become very small and the wear rate would be high due to not enough surface area.

The pictures are not Aston Martin pressure plates.