vettef6

Instead of using the stock clutch fork ball stud I was told to use the longer one from the ZR1 when changing to a smfw.

When the engine is idling in neutral there is no chatter or vibration. Depressing the clutch pedal just a little, I get a metal chatter and the engine dies out on me. Starting the engine with the clutch depressed doesn’t work at all.

Any ideas before I take everything apart??

RichS

I use a singlemass and use the stock stud. I can't see why you would use a longer one. I had my stock one loosen up and turn out to make it longer. When I depressed the clutch pedal the fork arm rubbed the pressureplate. I be that is what is happening to you with the longer stud.

byebyeL98

What SM flywheel are you using? From your sig, I am guessing that you converted from an auto to a ZF 6 speed. Did you use an aluminum flywheel replacement for the OEM dual mass? Or did you use a single mass from an earlier model vette (like an '87)?

If you used an OEM replacement aluminum SM, you would most definitely want to use the shorter, stock pivot ball stud. The longer ZR-1 stud would cause the back of the clutch fork to contact the pressure plate, which I am pretty sure is happening in your case.

vettef6

Yes I'm using the Fidanza alum. flywheel and the CC stage 2 clutch. And yes, I did do the conversion from an auto to a '96 ZF 6 speed.
This might also be the reason for it being so hard to depress the clutch pedal.
Tomorrow I'll take everything apart and we'll see if all three of us are right.

Thanks for your comments.

LD85

If the engine dies when you push on the pedal it is because the back of the clutch fork is contacting your Pressure Plate and stopping the engine and the grinding noise is the fork on the PP.

Been there , done that

byebyeL98

Then you should not be using the longer, ZR1 pivot ball stud. The clutch fork is coming into contact with the pressure plate LONG before the clutch is disengaged. The clutch pedal probably gets real hard to press about half way down, right? Don't force it, you can actually bend the clutch fork doing that.

Unfortunately, you'll need to pull the transmission back out to replace the pivot ball stud. Once you do, bolt the slave cylinder back into place BEFORE re-installing the transmission, slide your clutch alignment tool into place, and test out the clutch pedal. Have someone push it all the way in and use a small mirror to look into the bell housing to make sure the fork is not contacting the pressure plate.

This would also be a good time to make sure your flywheel / pressure plate assembly has the proper balance / imbalance, depending on the rotating assembly used, as it looks like you've got some engine modifications as well.

Good luck!

vettef6

LD85, that is also what I'm thinking of, this is why I said, I think it's the ball stud being too long and therefore the fork is coming against the pressure plate.

ByebyeL98, I also had the same idea of depressing the clutch pedal before installing the trani. The idea with the mirror is good! BTW, I had the flywheel and pressure plate balanced to O prior assembly.

byebyeL98

Glad to hear it.

Let us know how you make out

vettef6

It took me 4.5 hrs to fix the problem, now everything is great!!
As we all presumed, it was the ZR1 ball stud, which was causing the trouble. The fork was bent and so was the pressure plate. Can’t post pictures, but the picture of the pressure plate is very interesting. Well, I straightened the fork but couldn’t do anything about the bent lip of the pressure plate. When depressing the clutch pedal the leaf springs do touch the PP lip a little. But since the clutch works fine I left it as it is.
BTW, I can depress the clutch pedal with 1 finger, that’s how easy it goes now!!

Thanks for the advice
Arnold