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-   -   62 clutch to hard to push (https://www.corvetteforum.com/forums/c1-and-c2-corvettes/3015030-62-clutch-to-hard-to-push.html)

aworks 03-07-2012 06:06 AM

62 clutch to hard to push
 
I have what sounds to me like a stupid question. What is the purpous of the giant spring?

I have all the stock rods and zbar mocked up in the car now with no spring. The clutch is just a Hays dia. unit. There is no way I could drive this car. The clutch is way to hard to push. I don't have a spring to try but it makes no sense to me that it would help the clutch disengage. On the other hand I do not understand why it would need the giant spring for a return. I am no expert on these early cars. Midyears no problem.

So what do you guys think? I can go hyd. but was never a big fan.

Brian G.

BarryK 03-07-2012 07:11 AM

something doesn't sound right. I'm surely no expert on anything, C1 or C2, but I know how my stock C2 clutch feels and while i only drove a C1 car twice the feel and "weight" of the clutch was really no different than my '65 clutch.

If your clutch is really that hard to push than something has to be wrong.

sorry, I know this gives yo no answer to your question but it's an independent outside observation.

cam30era 03-07-2012 07:12 AM

I am not an expert on '62s. But it sounds like what you are describing by "giant spring" is the over center assist spring. And yes, it does indeed reduce the effort in the bottom half of the clutch pedal travel.

ejboyd5 03-07-2012 07:29 AM

A C1 clutch should be no more difficult than any other to disengage. The overcenter spring does make a difference, that's why it is part of the design. Even without it, the clutch shoud be operable so perhaps something is not arranged correctly - pictures of your assembly would be helpful.

Frankie the Fink 03-07-2012 07:53 AM

My '61 clutch is just as smooth as can be and its the same setup. The over-center spring is a help not a hindrance...there is an adjustment for it in the ST-12 manual and when properly setup the spring should require 6-9 lbs to move...that's about what some DA revolver triggers are set at.

You have something else going on....make sure your Z-bar is perfectly perpendicular to the frame and not cocked in its length between the ball studs on the frame and engine....make sure the clutch bracket under the dash isn't set for the 'fast action' position. Look in your ST-12 manual to research this.....it gives quicker clutch release but with more effort.

The clutch rod bushing at the top of the Z-bar needs to be VERY well lubed for smooth operation as well.

Disconnect the clutch at the adjusting rod and try the pedal again....this eliminates clutch fork, reversed throwout bearing problems, etc..

wmf62 03-07-2012 08:02 AM

and as silly as it seems, make sure that you haven't reversed the z-bar; the longest arm should be at the top.
Bill

Frankie the Fink 03-07-2012 08:06 AM


Originally Posted by wmf62 (Post 1580209532)
and as silly as it seems, make sure that you haven't reversed the z-bar; the longest arm should be at the top.
Bill

OMG....absolutely check that! Although I don't see how you could mount the clutch rod bushing that way.

BTW - Now is the time to drill a hole into the center of the hollow Z-bar shaft and insert a Zerk fitting so you can keep it well greased while it is on the car in the future !!!

C-1 Generation 2 03-07-2012 08:17 AM

Something must be wrong someplace.
On my 62 the clutch is not hard to push down at all. In some of my other new model manuals with hydraulic clutches the effort is less but the good feel is not there.
I have a friend that just recently had a 5-speed installed in a 65 Mustang and a hydraulic clutch and his effort is more than mine.

Mark_Milner 03-07-2012 08:37 AM


Originally Posted by wmf62 (Post 1580209532)
and as silly as it seems, make sure that you haven't reversed the z-bar; the longest arm should be at the top.
Bill

:iagree:

Surprising how many get installed upside down in a C2. Most assume it is the same either way but they are not.

wmf62 03-07-2012 08:46 AM

SOMETIMES things just happen... when we put the new engine in the 62 we just couldn't get the clutch to fully release no matter what... the TO bearing was right, the fork was good, z-bar good, pivot ball new, etc.. we finally had to fab an extension to the bottom arm of the z-bar so we could get sufficient travel. the downside was that it made an 'easy' pedal harder to push...

Bill

aworks 03-07-2012 10:44 AM

I'll check out some of the things you guys came up with. I'v built alot of cars and never ran into a problem. I still don't get why it needs that size spring. I know the z bar is right cause you could not put the bushing in the wrong side.

I need to get some help in the garage so I can watch what is going on under the hood.

wmf62 03-07-2012 10:47 AM


Originally Posted by aworks (Post 1580210849)
I know the z bar is right cause you could not put the bushing in the wrong side.

good point
:thumbs:
Bill

MikeM 03-07-2012 11:12 AM


Originally Posted by aworks (Post 1580210849)

I still don't get why it needs that size spring.

That spring is needed only if you are using a three finger style clutch like original. Diaphragm pressure plates don't need the assist.

jim lockwood 03-07-2012 11:14 AM


Originally Posted by aworks (Post 1580210849)
I still don't get why it needs that size spring. I know the z bar is right cause you could not put the bushing in the wrong side.

Brian,

The original pressure plate in the early cars was a three finger, Borg & Beck style. They take a fair amount of pedal effort which was partially mitigated by that big, over-center spring.

I've got a more modern diaphragm pressure plate in my '60 and, in lieu of the Godzilla spring, I've got a short hardware store spring.... not unlike a short screen door spring. Works fine.

Jim

Kerrmudgeon 03-07-2012 11:27 AM

Are you sure of what Hayes clutch you bought? They do make heavy duty racing clutches as well as regular duty. If your pressure plate alone is tough to push and your rods are all in proper position, and the pivots are all well lubed, I think you have one that will build leg muscles! I had a heavy duty type clutch in my 66 and I used to shift to neutral at stop lights to get a break for my leg! The stiffer the clutch means less slipping at high RPM, and launches.:thumbs:

Frankie the Fink 03-07-2012 01:16 PM

If you will do as I suggested and disconnect the clutch adjusting rod and then try the pedal you will quickly know if your linkage geometry is bad or you have problems in the throw out bearing/clutch/pressure plate area !

chris ritchie 03-07-2012 04:01 PM

Something's wrong. Even without the Godzilla spring, it shouldn't be hard to depress the clutch pedal on a diaphragm clutch.

The purpose of the Godzilla spring was to help depress the Borg and Beck type clutch. They could be hard to depress. But not a diaphragm type. Most people don't use the spring with a diaphragm clutch.

aworks 03-07-2012 06:21 PM


Originally Posted by jim lockwood (Post 1580211119)
Brian,

The original pressure plate in the early cars was a three finger, Borg & Beck style. They take a fair amount of pedal effort which was partially mitigated by that big, over-center spring.

I've got a more modern diaphragm pressure plate in my '60 and, in lieu of the Godzilla spring, I've got a short hardware store spring.... not unlike a short screen door spring. Works fine.

Jim

That dose explain the heavy spring. I need to pull the wheel well header off and start looking real close. It is a performance clutch but I have used the same one in other cars with no problem.

I'll get to it on sat. I'll post what I find.

Brian G.

Kerrmudgeon 03-07-2012 11:02 PM


Originally Posted by aworks (Post 1580215210)
That dose explain the heavy spring. I need to pull the wheel well header off and start looking real close. It is a performance clutch but I have used the same one in other cars with no problem.

I'll get to it on sat. I'll post what I find.

Brian G.


Performace clutch!
:willy:
Specs change for manufacturers parts, and different applications get different results as well. Call up Hayes first and ask them what pedal effort would be expected with that unit. You may save yourself a lot of screwing around with one call.:thumbs:

Pilot Dan 03-07-2012 11:08 PM

The Big Spring
 
Probably the most misunderstood part in the system. They call it a "gorilla" ect.... truth is when adjusted PROPERLY it acts as an over center helper and in fact the pedal pressure to engage a C-1 clutch is a lot less than a C-2 IMO. The problem for many is they do not adjust it correctly and in that instance it can work against you instead of assisting. The ST-12 oulines the correct process which DOES work. :smash: Pilot Dan


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