This is probably something simple but the discovery may be painful.

There are some clutches, like Centerforce, that require thin flywheel bolt heads and a modification on the flywheel recess otherwise it will hang the disc.

Honestly, langg, there is nothing very common, like something you see all the time, that would cause this and there just ain't that many parts that could do this. I have seen broken equalizers that do this. I've seen stuck discs that would do this. I've seen the wrong geometry in the linkage/bearing/pivot do this. And I've seen the wrong or improperly installed clutch disc do this. It it isn't one of those...I'm lost.

 

I'm lost also. That's the frustration. Everything is new and 'Corvette'. It should work.

The feedback from everyone has been helpful and I appreciate all the ideas. I guess I have been looking for a silver bullet solution that I can employ without removing the transmission (again). I am getting fairly good at it now though. Around an hour out and another hour in.

I have ordered another fork and fork pivot. When I have them in hand, I'll remove all down to the flywheel and start over. I'll check everything that people have suggested from the flywheel bolts on although, with a 'stock' clutch, it would be rude if the bolts required mod.

 

Most of my problems in thia area have been with either the wrong throwout bearing or the clutch fork ball stud. I have had to actually machine the ball studs to let them extend into the bellhousing further. I solved most of my problems by buying complete kits (clutch, pressure plate, release bearing) all from the same manufacturer.
As an other option, I believe there is an adjustable clutch linkage rod(the one from the clutch fork to the cross linkage) used on other product lines (Chevelle, Camaro, Nova) that will work in place of the fixed length one used in Corvettes. This would allow you to lengthen or shorten the travel of the clutch fork.

 

An Update.

I replaced the pivot stud and the fork. I checked the surfaces of the disk, pressure plate and flyuwheel. After reassembly, I can manually turn the rear wheel with it in gear and the clutch in (off the floor naturally). If I start it in neutral, I still can't get it in gear. I can drive it including stopping at stop signs, etc. But I still can't change gears when stopped with the motor running.

Next stop - more 'throw' from the bellcrank.

 

Is it possible your shifter is installed incorrectly?
Can you shift through the gears with the motor off and clutch depressed?
I'm a little confused by your last post though. If you are starting it neutral but can't get it into gear how are you able to "drive it including...". Are you forcing the shifter to get it into some/any gear? If so is this hard to do/requires alot of force? If so, I suggest checking the shifter at this point.

 

If the instant you start to lift your clutch foot the car starts to move, your clutch needs adjustment. You should be able to move your foot at least 2 inches or more, before the clutch engages enough to move the car.(unless you own a C-4 or C-5, they are more like 5 inches..lol)

 

The clutch disengages enough that I can start the engine in any gear. It shifts when the engine is not running but when the engine is running the input shaft does not stop when the clutch pedal is depressed(unless the transmission is in gear). The sycronizers don't allow engagement due to too much relative motion between input and output shafts when the car is stopped and the clutch is depressed..

 

Ok Langg,

I've reread through all the posts and can offer a few ideas.

A) I see in the thread that you have "adjusted all the slack and then some" out of the pedal. But in your last response you say that you are getting enough movement from the currently adjusted position that you can start the car with the transmission in gear. So my question...is there any more adjustment left on the threaded clutch adjustment rod that you can impart further clutch travel at this point OR are you "at the end of your rod" so to speak.

B) And what might be a better possibility; are you absolutly sure that you correctly placed the throw-out bearing on the clutch fork? There is a right and an easily missed incorrect way to slide the fork onto the bearing. If you've got it wrong that could be the source of your travel problem as the bearing would bind and/or be limited in its travel prior to completely disengaging the clutch.

C) You say you are converting your Auto to a 4-speed. Did you check that you used the proper flywheel to crank bolts (the thin ones). If not the clutch is riding on the hub & bolts vs. the flywheel & friction material. This has the same result as installing the clutch disk in backward.

D) Your input shaft could be bottoming out in your crankshaft bore which would also cause difficult shifting. As would a binding pilot bearing.

E) Last; your motor mounts could have excessive play which would take out enough geometry from the linkage that you cannot disengage the clutch sufficently.

 

If you can't sleep tonite, read this:
http://media.centerforce.com/DiagGui...cGuide04DL.pdf

 

What makes the transmission input shaft stop rotating when the clutch pedal is depressed? I know that friction in the pilot bearing or between the flywheel/pressure plate and the clutch disk will keep the input shaft turning. Where does the 'friction' come from to stop it?

 

I recently did the same thing; replacing the awfulmatic for a four speed. I have a 71 Muncie in my 1981. love it.
I too had lots of trial & error experiences. You did not say what year you muncie was...Working w/Hurst, I found out that, on my car, I had to use the linkage kit for a 71 but the shifter for a 81.
Could this be a consideration? I wish yuou well,,,jim

 

The car is a '75, the tranny is a '71 M22, the shifter is a new Hurst for a '75. What did you run into that caused you to use different vintage shifter and linkage? My shifter bolts to the transmission since the auto frame does not have the bracket.