C1 Throw-out Bearing Woes!!

[Peter Cipriani]

Last year about 700 miles ago I replaced my Orginal three finger clutch Ass., throw-out bearing,pilot bearing and resurfaced the flywheel.The new clutch is a Diaghram Type Ass. The Federal Mogel throw-out bearing has failed already!! I noticed that the length is 1 3/4" The original three finger clutch used 1 1/4" long throw -out bearing.

Is the throw-out bearing to long? This is the recommend bearing for this diaghram clutch Ass.?? Any suggestions would be appreciated!!
Peter

[Joe L.]

Re: C1 Throw-out Bearing Woes!!

Peter-----

The original clutch bearing for your application was, indeed, 1-1/4" in length. The replacement bearing must be 1-1/4" in length. If you got one that was 1-3/4" in length, then you got an incorrect bearing and this is definitely the cause of your problem. For some strange reason, many folks, including parts men at auto parts stores, think that Corvettes used the longer release bearing. While some Chevrolets did use a release bearing that was 1-7/8" long, the only Corvette that EVER used this size bearing was early 1955.

A correct length Delco bearing is available under GM #15680264 or Delco #CT 24 AG.

[Bob McCorkle]

Re: C1 Throw-out Bearing Woes!!

I had all that trouble with my C1 through the years...Get a whole kit,i.e. three finger clutch, pressure plate and throwout bearing from Fort Wayne clutch. I never had any luck with those diaphram clutches. I know Corvette central carries the same kit, from the same place.

[Bob McCorkle]

Re: C1 Throw-out Bearing Woes!!

Fort wayne clutch http://www.fortwayneclutch.com/clutch.html

[Peter Cipriani]

Re: C1 Throw-out Bearing Woes!!

I just got back from the clutch aftermarket place. They claim this diaghram clutch has a plateau(flat area) where the fingers come together. It will shorten the diaghram height which allows for the longer bearing??? They gave me a deal on a longer bearing replacement. If I cannot adjust proper freeplay they will give me a refund. I also ordered and received one from AC Delco the correct 1 1/4". I will see which one fits best when adjusting freeplay.

Bob,I still have the original three finger clutch. I will get it rebuilt and if this problem continues I will go back to the three finger arrangement. I like the soft, smooth feel of the diaghram clutch.

Thanks for your advice!!
Peter

[William V.]

[Joe L.]

Re: C1 Throw-out Bearing Woes!!

Peter-----

That's something that I hadn't considered; the diaphragm style clutch might require a different clutch release bearing than the 3 finger, original type. However, for what it's worth, Corvettes from 1956 through 1981 all used a 1-1/4" release bearing except for 64-70 which originally used one that was 1-7/32" long (but are now SERVICED by the 1-1/4" long variety). All 63-81 originally used a diaphragm clutch in conjunction with the 1-1/4" bearing.

Of course, this doesn't say that a C1 CONVERTED to a particular aftermarket diaphragm clutch will use a 1-1/4" bearing. I would have to think that the folks that sell them would know best. But, who knows?

[Doug Flaten]

Re: C1 Throw-out Bearing Sob/War Story

About 18 years ago, shortly after I got my '61, the bearing started squeaking on a 100 mile trip to Houston. Thirty miles into the trip, it was squealing. At a mall parking lot, the pedal went to the floor and the bearing shelled. When I got towed from the parking lot, we were stopped by a couple of bearded Miami Vice looking cops driving a Corvette. They were working a Corvette theft detail. Luckily my sob story and insurance card satisfied them as to my proof of ownership. Looking at the inspection cover and seeing a little ball in the drain hole, I thought it was pretty neat that there was a check valve in the cover's drain hole. Of course when I pulled the cover, the remaining ball bearing and other pieces fell to the floor. Anyway it had a replacement diaphram clutch. Having never worked on a car with a diaphram clutch, I did not know what they were supposed to look like. The parts man gave me a plate with a bunch of straight diaphram fingers. I told him this must be the wrong part because it did not match the configuration of my clutch that had fingers which were all bent in at 90 degrees. To which he replied "they ain't supposed to be bent". My bearing had pushed all the way through the pressure plate and bent every finger nice and uniformly. I decided I liked the beefier look of the 3-finger clutch and went back to it. I missed my college graduation ceremonies replacing the cluctch innards and putting Heli-coil inserts in the bell housing at a friend's house. Hey we are all ignorant at some point in our lives. It's just that some of us take opportunities to advertise it.