My clutch on the 62 is very stiff....hard to push in...
A while back there was a comment about two holes either in the clutch pedal or in the z-bar for either a quick acting clutch or a longer throw and thus softer pedal. I can not find the two holes. I may not have 62 clutch z-bar parts as the vette is put together from many sources.
Is there such an adjustment and how do I make it?
My old back needs all the help it can get.
Also are there softer clutches than stock type of clutch such as center force II....is this a softer pedal than stock? I have about 400 HP to put to the road.

Thanks
Dave62

 

The adjustment is done on the clutch pedal assy up under the dash.

It isn't necessarily as simple as it seems to change the setting as some brackets have to be repositioned, IIRC.

It is covered in the service manual ST-12.

Doug

 

Note that there is also an adjustment for the so called Godzilla spring (the large clutch return spring located under the hood that goes from the frame to the bracket bolted to the Z-Bar).

If some missguided soul replaced that spring with a softer spring, then clutch effort will be INCREASED (not decreased), since it is an overcenter spring designed to help pull (while you push) the clutch pedal. The adjustment for that bracket & spring is critical (too much spring "pull", and the clutch can hang on the floor, while too little will increase the effort to push the clutch). The adjsutment spec is covered in the ST-12 (spec. is 6 to 9 lbs. with the clutch fork push rod disconnected when measured at the pedal). Adjustment is made using a large crescent wrench (12" or so) on the top of the bracket, with the 2 bolts holding the bracket being loose. Make an adjustment, tighten the bolts, and measure the pedal pressure. Repeat the process until the pedal pressure is within spec. Note that with the fork rod disconnected, pushing the pedal down past overcenter will slam the pedal to the floor. This is normal! Just reconnect the fork pushrod, and all be OK. Once adjusted properly, I know you will like it a lot better.

However, make sure your clutch fork pushrod is adjusted correctly as well (if a diaphram clutch plate, use the air gap method per the manf. spec.).

Plasticman

 

If you might be interested in replacing your clutch assembly: I recently ordered a LuK clutch from Dial-A-Clutch. Shipping was free. The clutch assembly came with all pertinent parts including a new pilot bushing (2 types), pilot tool, throwout bearing, and spline grease.

 

I second the LUK, no problems with my 365-SHP motor, and not to harsh on the knee.

Mark

 

I'm running a centerforce II clutch and I love it! Much easier on the leg than previous clutch assembly. Engagement is smoothe and positive with 400+hp. If you are missing the godzilla spring (as some folks remove it) put it back on. As plasticman mentioned, it also keeps your left leg from getting much larger than your right.

 

I had the same problem in my '62. Here's how I fixed it.

1. Somebody had "cob-jobbed" my "Z" bar to shorten the stroke which increased the effort. Got a new one. The longer stroke gave me more leverage, decreasing the effort.

Make sure everything is greased. The "Z" bar is greased at both ends. Years of increased effort and no lubrication finally broke the clutch ball on the frame and wore away a part of the ball on the bell housing bracket.

2. Get rid of the 3 fingered Borg and Beck type clutch pressure plate. That type has very high pedal pressure. Get the diaphragm one instead. That's what Chevy did after 1962. Only your left leg muscles will know the difference. When you do that, you can get rid of the "gorilla" or "godzilla" spring. The diaphragm type clutch pressure plate was used on plenty of high horsepower applications. But if you're still concerned that the diaphragm type clutch is insufficient for your high HP application, get the Centerforce one. If you get rid of the "gorilla" spring, you'll need to fashion a pullback spring. Search the archives under "gorilla" or "godzilla" for John Hinckley's elegant solution.

3. The Luk clutch set is sold by many vendors. When I bought mine, dialaclutch.com was the cheapest. But you may be able to get it locally. Also heard good things about the Centerforce. I'm very happy with the Luk. The Centerforce is more money. You won't be impressed with the cheesey looking plastic throw-out bearing. But it works just fine. I'm told that's the way all the OEM throw-out bearings are today.

4. The 2 hole adjustment for the short throw clutch is under the dash, on the pedal. The ST-12 will tell you how to do it.

 

Thanks for the comments guys. I do have the diaphraghm clutch plate.
I checked under the dash and clutch pedal rod is in the proper position for "soft" clutch....I can see how the plate is moved and rod is turned over to give a "fast" clutch.
I have the clutch spring...but sure have never adjusted it. It is the correct spring from Corvette Central when I built the car several years ago.
I will take z-bar out and lube it well today. I will adjust the spring.
The actual pedal pressure is just a little much for my lower back as I injured it this summer and then did not get to drive the 62 much at all.
I have a couple of other vehicles with clutches and they are no problem for me.....
I guess if all else fails I can go with the Center Force II clutch...and as a last resort some type of automatic tranny...
Any other options for a soft clutch?

Thanks,
Dave62