Clutch Chatter

[Bill Pritchard]

I recently bought a 69 Chevelle SS396 with M20 4 speed and it has clutch chatter when slowly engaging the clutch, either when just starting out from a stop or when downshifting. I bought the car knowing that it had a problem in this regard, so it was not a surprise to me....I just want to get the problem fixed.

The car has all new (remanufactured) clutch disc and pressure plate, new throwout bearing and pilot bushing, and the flywheel was resurfaced. The M20 was completely gone through by Crash. It was initially assembled with all these new components and this shuddering problem came to light. Everything was removed, inspected, cleaned with lacquer thinner to ensure absolute cleanliness, and reassembled. The problem still was there. I have removed everything again and am looking for the root cause. Have a look at these pics of my clutch fork with throwout bearing installed on it. The spring steel 'tangs' that hold tension on it are not well centered on the face of the throwout bearing collar. On the one side, the tang is barely making contact with the edge of the bearing collar. Does anyone think this could be the cause of the shuddering? I examined all other components and could find nothing else that looked suspect. With the bearing removed from the clutch fork, the tangs do not appear terribly offset in the opening on the fork.

Before I tore this all apart, I tried jacking up each side of the engine to see if the motor mounts might be broken, as I know that could also cause shuddering....they appeared to me to be solidly attached.

Since I have everything apart, I do plan to install another clutch kit using new, non-remanufactured components. I will be interested to see if another throwout bearing has the same offset appearance as this one does. If so, I will probably try another clutch fork.

Any help would be greatly appreciated!!