C2 clutch and throw out bearing

[William G.]

OK, I just read a long post put on C2 clutch problems and it was informative. However, it did not address the throw out bearing. Last night with the engine and transmission mostly put back together and in the car, I went to adjust the clutch linkage. Running the clevis all the way to the end of the clutch rod would not bring the throw out bearing in contact with the pressure plate fingers! After waiting for the "Blue Cloud" to disappear, all I could come up with was the throw out bearing disconnecting from the fork and sliding back against the front of the transmission.

Anyone else ever had this happen?

This is the one time I wish GM had made a removable inspection plate on the bottom of the bell housing. I have been so careful not to ding, or scratch the car, or the finish on the rebuilt engine, I hate the thought of having to unbolt everything and possibly remove the engine and transmission from the car.

Anyone know if it is possible to reinsert the throw out bearing into the fork, via the rubber boot hole where the fork goes through the bell housing?

Short of a major problem with the pressure plate, I can not think of any other reason for no clutch. The pressure plate looked fine when it was assembled out side the car.

Bill

[Paul S.]

Re: C2 clutch and throw out bearing

to my knowledge and experience you are not going to do anything threw the rubber boot . did you put a clutch , pressure plate AND throwout bearing in? not to be smart , but is it the correct pressure plate and throw out bearing and clutch fork / ball for clutch fork? is the clutch rod right ?

[William G.]

Re: C2 clutch and throw out bearing

Paul,

The flywheel is the original one that came out of the car. The pressure plate was previously in the car and I had it rebuilt. That said, the person who rebuilt it, said there was not enough "pre load", and tightened it up. I do think it may have brought the flex plate fingers in a little, but not so much as to not have any adjustment left on the pedal rod.
I did buy a new throw out bearing, from Corvette Central. It was the same length as the one that came out of the car. The fork is also the original and all I did was replace the ball stud, as the original was badly galled and worn.
I assembled all of the parts outside of the car, along with the transmission. I thought I was careful when inserting the input shaft so as not to knock the throw out bearing off. All seemed to go together OK. All of the other parts of the clutch linkage are the originals from the car.
It has me really baffled and frustrated!

Bill

[Russ S.]

Re: C2 clutch and throw out bearing

I have a friend with a 67 SB that has the exact same problem. Every thing on his car is new including the flywheel. All parts are from the same source. He has called different people including the manufacture of the parts to no avail.

[Edward J.]

Re: C2 clutch and throw out bearing

Bill, what I have seen sometimes is the flywheel get machined more than once and what this will do is make the clutch adjustment go to the end of its travel, What can be done to fix is the is a 67 style clutch rod its is a one inch longer than the 63 to 65 ?? At the point where the car is back to together the only other fix maybe a shim behind the flywheel to bring it back into spec. they come in a couple of different thicknesses.

[William G.]

Re: C2 clutch and throw out bearing

with what reply?

[Rich G.]

Re: C2 clutch and throw out bearing

After re reading your first post, it sounds like you have the correct parts, but FWIW.......

When I bought my 66 many moons ago it had a homemade clutch rod. Decided to buy the right one from LICS. The correct one, which was shorter than the one Bubba made would not disengage the clutch. We took the trans out for other reasons and, according to my mechanic, the throw out bearing was incorrect. I'm not sure if he said there was a difference because it was pass car vs Vette or it had to do with the type of clutch installed.

Rich

[Rich G.]

Re: C2 clutch and throw out bearing

Deleted duplicate post
Rich

[Stephen L.]

Re: C2 clutch and throw out bearing

Did you get the throw out bearing mounted correctly on the clutch arm??? A couple of photos.... The spring "tangs" must be in the groove.

[Paul S.]

Re: C2 clutch and throw out bearing

3 comments :

I can't think the throw out fell off fork and slid forward , think it would have just fell into bell housing

never had a pressure plate rebuilt (?) i have always bought new ones

is ball stud the same , there are different ball studs

[William G.]

Re: C2 clutch and throw out bearing

Rich,

Both the Hayes pressure plate and the original rebuilt GM pressure plate are the same type. Flexible diaphragm! The throw out bearing I was using in the previous engine/ clutch set up is the same as the throw out bearing I bought from Central Corvette. I matched them up before installing the new one!

[William G.]

Re: C2 clutch and throw out bearing

I did match the new ball stud to the original, which had never been out of the bell housing. They were pretty darn close in length. What little difference there was in the length should not have changed the throw of the fork hardly at all. One would think, when you buy a ball from a major Corvette parts supplier, specifying the year and engine size, the correct part would have been sent!

[William G.]

Re: C2 clutch and throw out bearing

Thanks for the pictures! Honestly, I don't remember. it was about six weeks ago that I installed the tranny to the engine, while it was out on the floor. I guess when I get the bell housing separated from the engine and can look inside the bell housing, I will know. That said, if the spring tangs are not in the groove, what is the result, other than sloppy / noisy operation?

[Joe L.]

Re: C2 clutch and throw out bearing

Rich,

Both the Hayes pressure plate and the original rebuilt GM pressure plate are the same type. Flexible diaphragm! The throw out bearing I was using in the previous engine/ clutch set up is the same as the throw out bearing I bought from Central Corvette. I matched them up before installing the new one!

William------


The most likely cause of your problem is as Steve Lavigne describes above. This is a VERY common problem. If so, there is no way to correct it other than "going back in".

On a Corvette, proper clutch operation is critically dependent on the proper and exact configuration of all clutch system components. I have found that machining of the flywheel and/or pressure plate substantially affects original configuration and that's why I do not recommend that either be performed. If the flywheel or pressure plate requires surfacing, I highly recommend replacement.

As far as diaphragm pressure plates go, there are more than one type. The "bent finger" is the type used on most Corvettes and is the type that MUST be used as a replacement.

[Stephen L.]

Re: C2 clutch and throw out bearing

Bill, If the throw out bearing is installed with the tangs out, the required "travel" of the bearing will increase.. (bearing further from the clutch diaphragm when retracted). The geometry of the entire system is such that a small travel of the bearing results in a large travel of the clutch arm at the adjustment point. That sounds like what you are experiencing... you have run out of adjustment travel (length). You could calculate the geometric distances based on the clutch arm dimensions etc. before you take it apart....... Someone on this forum might know the distance the bearing/clutch is designed to travel from fully engaged to fully released clutch.