Doug1964

I am swapping out my engine and doing some work on my transmission in my 1960. The transmission is not stock and is a Muncie m21. Anyway, I always had a strange whine coming from the clutch area. When I pulled the motor and examine the clutch fork and release bearing, I notice that the clutch fork opening between the two forks is too narrow for the release bearing. In other words the release bearing will not properly insert into the fork. I am wondering if I have a c1 fork and a c2 release bearing in their from a prior owner or if I just have a crappy aftermarket release fork that is out of tolerance. Does anyone know if the release bearing diameters varied between model years or if the release fork opening width varied between years. Thanks.

Plasticman

Nope. Release bearing (throw out bearing) is the same width for all Chevys.

Pictures would help (of both fork and bearing).

And all C1 used the "short" version of the TO bearing.

What pressure plate style do you have (B&B or diaphram). If diaphram, are the tips of the fingers (where the TO bearing rides) bent or straight?

Was the fork riding behind the bearing, and only pushing it forward? If so, the TO bearing would not retract rearward (resulting in short TO bearing life).

Plasticman

DZAUTO

If you have ANY Chevy bearing fork, and are using the correct bearing, then there should be NO issues!
For example, in my 51 Chevy, I am using the STOCK 1951 Chevy throwout bearing fork and linkage with a 55-57 style bell housing (same style as used in early Vettes) with a Muncie and behind a built 383, and there are no issues.

rongold

Now, that's something I've never seen before--A SOLID CAST IRON FORK !!! All the ones I have ever worked with have been stamped steel.

DZAUTO

That's because you're a young puppy!
This style was used up through 54 on cars and into the late 60s on trucks.
From the pivot point of the ball stud to the centerline of the bearing, the dimension and geometry is the same on all Chevy bell housings/forks.

jim lockwood

What a contraption, Tom!

I take it that it's pulled from the rear because of the floor-mounted pedals in your old Chebby?

desertpilgrim

Any chance of a measurement of Your fork?

Doug1964

Here are some pics of the issue I mentioned. You can see in the photos that the release bearing will not go any further into the fork unless I beat it in with a hammer. If you look closely, you can see wear grooves in the bearing where the fork was pressing on the bearing. I actually have the bearing 180 degrees from where it was installed before. However, you can see that the wear marks are no where near the center of the bearing. The fork looks like a newer repop fork to me and I am wondering if the opening was just never wide enough. I am thinking of just using a dremel to open the fork to clear a new bearing once I get a new bearing. It looks like the opening between the forks is about 1-5/8" to 1-11/16". I could not measure the bearing because my caliper is broken but I thought one of you guys might know the standard bearing diameter. Any thoughts?

Plasticman

See what you mean, and I agree that is probably was a very poor repop. Your pictures don't show the linkage end, so check the below thread (post #14) to confirm it is correct:

https://www.corvetteforum.com/forums...djustment.html

Plasticman

Doug1964

Thanks. I will definitely follow along on that adjustment thread.

buns

The old release bearing from my '66 is measuring 1.62" in diameter. Distance between the "ears" of the fork is 1.67".

AZDoug

A little grinding on the fork will fix that if you decide not to replace the fork.

Doug