63 Clutch fork???

[Boyan B.]

OK, I know that 63 clutch forks differ from later years, but here is my question. I have what appears to be (2) 63 clutch forks. Both look identical except for one minor detail. One fork has a small dimple with a 1/8 inch hole to accept the spring end near where the clutch rod engages the end of the fork. I know this is a correct 63 fork.

The other fork has the dimple where the spring would go, but no hole.

I would like to know if anyone knows the application for the fork without the hole for the spring. Can I use it if I just drill a hole in it? Or is it completely for some other application and wont work on a 63 clutch system?

Boyan

[Duke W.]

Re: 63 Clutch fork???

I don't have a specific answer to your question, but FWIW I assume the dimple was part of the forming dies for the purpose of indexing the required hole for the spring, and for whatever reason it was not drilled.

If the pieces are otherwise absolutely identical, I see no reason why you can't drill a suitable size hole and use it on a '63.

Duke

[Boyan B.]

Re: 63 Clutch fork???

Yeah Duke, I could not find any other difference. My only concern is that there is maybe something that I didnt catch. Just FYI, I already drilled the hole in it and its installed in my chasis. I came across another fork which already had the hole. I just have to decide if I want to remove the transmission to change it to the one I know is 100%.

Boyan

[Joe L.]

Re: 63 Clutch fork???

Yeah Duke, I could not find any other difference. My only concern is that there is maybe something that I didnt catch. Just FYI, I already drilled the hole in it and its installed in my chasis. I came across another fork which already had the hole. I just have to decide if I want to remove the transmission to change it to the one I know is 100%.

Boyan

Bryan-----


One thing to be careful of is that many of these clutch forks had very subtle differences in angularity. It can be very difficult to compare them, even side-by-side, and discern a difference.

The 1963 Corvette clutch fork was unique to that year and different in terms of pushrod attachment than any other year Corvette. However, it was similar to that used on other Chevrolet models, some later Chevelles, in particular.

If the forks for 2 or more applications were the same except for the presence or absence of a return spring anchor hole, I would expect that GM would have used one part number and included the hole whether it was to be used, or not.

On the other hand, if there were other differences between the forks for 2 applications and one used the hole and the other didn't, then I would expect the one that needed the hole to have it and the one that didn't to not have it.

Is it possible that the one you have without the hole was simply a manufacturing mistake with respect to the lack of the hole? Yes, it's possible but very unlikely.

[Boyan B.]

Re: 63 Clutch fork???

I agree that a manufacturing deffect is HIGHLY unlikely. So how do I figure out what application the one WITHOUT the hole is for?

Boyan

[Joe L.]

Re: 63 Clutch fork???

I agree that a manufacturing deffect is HIGHLY unlikely. So how do I figure out what application the one WITHOUT the hole is for?

Boyan

Boyan-----

I don't have an answer to that. Unfortunately, GM never stamped a part number on these forks. SERVICE parts have a parts label or ink stamping with the number, but once that's gone, it's gone.

[Tracy C.]

Re: 63 Clutch fork???

Boyan,

Here is a pic of a NOS 63 fork you can use as a quick comparison reference. I have another fork without the spring hole but the hole for the clutch rod is offset rather than centered. I thought it was correct for my 63 until I saw a bunch of real ones when I OJ'd in Boston last year.

tc

[Boyan B.]

Re: 63 Clutch fork???

Tracy, thanks for the photo and reply. Your NOS fork looks just like my used one with the hole for the spring. What is driving me crazy is that the one without the spring hole looks exactly the same also. No offset hole for the clutch rod. The only physical difference that I can tell between the two is the absence of the hole (but there is a dimple) and the punched hole for the clutch rod is a touch smaller than on the "real" 63 one.

I'm just trying to muster up enough courage to leave my unk fork in there and drop the body to see if it works.

I'll probably be scared and change it out with the one I know is good.

Boyan

[Gerald C.]

Re: 63 Clutch fork???

Tracy,

Can you send me or post that picture of the NOS Clutch fork? In my research, the 63 should be able to accept the flat end of the rod that accepts a pin through the clutch fork and said rod.

Thanks,
Jerry

[Richard G.]

Re: 63 Clutch fork???

A couple pictures of the rod end.
IMG_2342.jpgIMG_2341.jpg

Maybe they will help?
Rick

[Boyan B.]

Re: 63 Clutch fork???

Wow, back from the dead thread! Still no difinitive answer to my original question. But I have good news, the fork I drilled the hole in has been working perfectly and been in the road for years.

Boyan

[Gerald C.]

Re: 63 Clutch fork???

Thanks Rick,

Again, I thought the 63 clutch rod had a flat end that fit inside a flat end opening with a pin on the 63?

Jerry

[Harry S.]

Re: 63 Clutch fork???

My spare 63 fork..

IMG_1490.JPG

IMG_1489.JPG

[Joe L.]

Re: 63 Clutch fork???

Thanks Rick,

Again, I thought the 63 clutch rod had a flat end that fit inside a flat end opening with a pin on the 63?

Jerry

Jerry-------


The 1963 clutch rod was unique to that year. The design was, basically, a "ball-and-socket". The end of the push-rod was round with a center pin which articulated with the hole in the center of the socket on the clutch fork to maintain the ball end centered on the fork.

While as far as Corvettes go, this configuration was unique to 1963, a similar configuration was used on other Chevrolet models. The rods are not interchangeable with Corvette, though.

[Gerald C.]

Re: 63 Clutch fork???

Thanks for the clarification folks