Odd 930 clutch problem

[logician]

Hi,

Question: is 1/32" too much side-to-side play on the clutch fork release shaft on an '86 930? This is the shaft that sticks down from the bell housing, on which the two release leavers are attached. I removed the two leavers and can pull the shaft side to side. I haven't measured the play exactly, but the movement is enough to see pretty easily. I'm thinking that the shaft bushings have become worn.

So the reason that I was investigating the release shaft is that the clutch pedal has a very funny gritty feeling when I push the pedal in. At first I thought it was just the cable binding, and that I might need a new cable. However, I realized that the gritty feeling only occurs when the engine is running -- puzzling. Just to be clear, the grittiness occurs only when the clutch pedal is in motion being depressed, or being released. The sensation occurs in a range about 1/2 through 3/4 of the pedal motion. There is no vibration when the pedal is held in any fixed position. Other than this gritty feeling, the clutch seems to work just fine -- very smooth.

I tried feeling around on the cluch lever, helper spring, and cable at the bell housing while I had a buddy push on the clutch with the engine running. The gritty motion is definitely coming from the clutch shaft, as opposed to the cable.

So all this has occured in 500 miles since I replaced the clutch, and had my transmission rebuilt by my mechanic. The grittiness has progressively gotten worse. I did have some problem engaging the throwout bearing when I put the engine back in, and as a result, I believe that I stressed the clutch cable and levers when I was wailing on the clutch pedal without proper engagement. I eventually got the correct engagement, after removing the engine and mating the engine and transmission a second time. Could the stress of wailing on the clutch pedal have been enough to deform the bushings on the release bearing shaft?

Do you have any ideas on what could be causing this odd gritty clutch behavior? Could this be due to the observed play on the shaft? Are there any other possibilities? Any help would be greatly appreciated!

Thanks!
-Juan

[dean]

It seems like you have bad bushings in the tranny. I don't think there should be any play in the shaft. I'll bet it was caused be a dry shaft, a very bad thing