'64 327/365 thow-out bearing question

[Tom L.]

My brother in law is at the tail end of a frame off resto on his '64 and is having a problem with his clutch, it won't disengage. His mechanic has the impression that there were two throw out bearings for '64, a long and a short. He called Ram, maker of the clutch, and they kind of confirmed it but had no real answer. Any help?? Thanks!!!

[Patrick B.]

Re: '64 327/365 thow-out bearing question

I think all 63-up Corvettes used a bent finger (conical) pressure plate and the "short" throw-out bearing.

[David L.]

Re: '64 327/365 thow-out bearing question

My 1964 Chevrolet Parts Catalog (Oct. 1963) lists GM # 900018 (described as 1 9/32" long) for 55-64 Corvettes (8 cyl.) (2nd design).

My 1965 Chevrolet Parts Catalog (Oct. 1964) lists GM # 900018 for 55-63 Corvettes (8 cyl.)(2nd design) and GM # 907538 (CT24K) for 64-65 Corvettes.

I have a NOS 907538 (CT24K) throw out bearing in my collection. GM # 907538 was replaced with GM # 907963 (CT24K1, 1 7/32" long) in May 1969 which was then replaced with GM # 908093 (CT24K1, 1 7/32" long) in April 1973 which was then replaced with GM # 908244 (CT24AF) in Dec. 1981. I also have a NOS 908244 bearing in my collection.

GM # 909422 (1 7/8" long) is listed for the 55 Corvette (8 cyl.)(1st design) in the two Chevrolet parts catalog previously mentioned.

If anyone has a NOS 1969-1973 bearing, GM # 907963 (1 7/32" long) I would be willing to trade my NOS 1964-1968 bearing, GM # 907538, for it. I need the NOS 907963 bearing for my 1970 Camaro SS350.

Dave

[David L.]

Re: '64 327/365 thow-out bearing question

The Dec. 1964 Chevrolet Parts Catalogue (Canadian) lists GM # 900018 for 1964 ALL with 327 & 409 engines "FIRST JOBS ND24E" and GM # 907538 for 1964 ALL with 327 & 409 engines "AFTER JOBS ND CT24K". I assume this means early and late models in the model year 1964.
You can find this page on the web, GM Parts Wiki, just Google "907538 bearing".

Dave

[Patrick B.]

Re: '64 327/365 thow-out bearing question

My 1981 Chevy Parts Catalog lists GM 908244 for 55-63 (1 1/4" long) and GM 908093 for 64-80 without any note about its length. My apologies; the change was in 1964 rather than 1963.

My 1970 Chevy Passenger Car Parts Catalog lists 909422 (1 7/8" long) for 62-63 Chevy and 64-70 6 cyl and low performance v8's and 907963 (1 7/32" long) (ND-HCT-24K) for 64-70 4-speeds and high performance v8's.

I always thought of the 1 7/8" bearing as the long bearing and the other one as the short bearing, but if the short bearing actually comes in 1 7/32, 1 1/4, and 1 9/32 inch lengths there are plenty of possibilities of mismatch.

[David L.]

Re: '64 327/365 thow-out bearing question

The link below might help.

https://www.forums.ncrs.org/showthread.php?103347-64-65-and-66-67-Clutch-Release-Lever&highlight=3729000+stud

[Joe L.]

Re: '64 327/365 thow-out bearing question

My brother in law is at the tail end of a frame off resto on his '64 and is having a problem with his clutch, it won't disengage. His mechanic has the impression that there were two throw out bearings for '64, a long and a short. He called Ram, maker of the clutch, and they kind of confirmed it but had no real answer. Any help?? Thanks!!!

Tom------

ALL 1964 Corvettes with manual transmission used a clutch release bearing that was 1-7/32" long (GM #907538). This bearing and its successors were discontinued a LONG time ago and replaced by a bearing of 1-1/4" length. Both bearing lengths were known as "short". The 1-1/4" bearing will satisfactorily SERVICE all late 1955-81 Corvettes.

The "long" bearing was 1-7/8" in length. As far as Corvettes go, it was used ONLY for early 1955 Corvettes.

[Chris D.]

Re: '64 327/365 thow-out bearing question

Tom, There are a surprising number of variants in cross shaft, push rods, pivot ball, and fork designs used during the 63-67 period. I recall an informative thread several years back that detailed these all out that some diligent searching would uncover. You might ask your brother in law if any of the linkage pieces were replaced in the restoration especially the cross shaft. They all look reasonably similar and have no part number stamping to nail down the proper application.

[Tom L.]

Re: '64 327/365 thow-out bearing question

Thanks for the replies. Those components are ones that I considered as a culprit but waited to see what people had to say. Thanks for the replies!

[John H.]

Re: '64 327/365 thow-out bearing question

Corvettes use the "short" (1-1/4") throwout bearing, with a diaphragm clutch with "bent" fingers that form a cone. The "long" (1-7/8") bearing was used in passenger cars and trucks with FLAT-FINGER diaphragm clutches. Photos below of both clutch types, with the "flat-finger" style on the left, and the "bent-finger" style on the right.


FlatFingerClutch.jpgLuK105Clutch.jpg