63clutch arm

[Larry Boden]

Hello All
Does anyone know the amount of offset of a stock 63 throw out bearing arm. After I changed my clutch from a high performance unit to stock I found Iam using every inch of pedal to get the clutch to disengage properly. I have got 1/4 inch of play at the top and I have to fully depress the clutch pedal for proper release. I am thinking I may have the wrong arm in there. So once again does anyone know the offset so I can measure mine and replace if necessary.

Larry Boden

[Joe L.]

Re: 63clutch arm

Larry-----

The problem that you describe is common to Corvettes, regardless of whether they have aftermarket clutches, or not. Aftermarket, "hi-performance" clutches may exacerbate the problem, though; that's the primary reason that I don't recommend using them.

I don't know what the offset is on the stock, 1963 clutch fork. However, I believe that it's the same as 64-81. The 63 differs only with respect to the attachment of the fork push rod. I don't even know if any fork is available other than the stock configuration. If there is, I think that it will likely solve one problem and cause other problems.

[Boyan B.]

Re: 63clutch arm

The 63 arm has the same offset as the 64 and up. It is different in attachment just like Joe said. There were several different throwout bearings used in 63. If everything works and it just feels off, I'd leave it alone. If you dont like it, you need to check all the parts to make sure they are all 63.

Boyan

[Larry Boden]

63 clutch arm

Thanks for the thoughts because I never considered the through out bearing. When I talked to the previous owner he said that considering that he had a scatter shield on it he may have very well have changed the throw out arm to match the new shield.
Larry Boden

[Joe L.]

Re: 63clutch arm

Boyan and Larry----

1963 Corvettes originally used a clutch release bearing that was 1-1/4" long. Beginning in 1964 and for several years thereafter a bearing that was 1-7/32" long was used. Later yet, things went back to the 1-1/4" bearing. The 1-7/32" bearing is long-since discontinued and replaced by the 1-1/4". I don't know of any source that currently has available the 1-7/32" long bearings, assuming someone wanted one.

Also, the 1963 clutch fork was unique in that it used a "ball-and-socket" type of articulation between the fork and the fork push rod. If yours still evidences this sort of configuration, it's likely the original fork. It is possible, though, that some aftermarket forks might have used this articulation configuration, too, but were otherwise different in terms of offset.