So today I got the clutch linkage all put together and tried 'er out.  Seems like things are working OK except the pedal won't come back all the way on it's own - it stops at the edge of it's free play, after the clutch fingers are fully relaxed, I'd guess.  It's easy to pull the pedal back with a foot, but something doesn't seem right.  Yes, I do have a new pedal return spring installed that goes between the Z-bar and the firewall steering column bracket.  And I followed the AIM instructions for setting pedal free play.  The total amount of play seems about right, just won't take it up on it's own.  I don't remember having this problem before I took everything apart.  

______________

Disconnect the clutch return spring at the cross shaft. Push the clutch lever until the pedal is against the rubber stop under the dash. Loosen the two shaft locknuts and push the shaft until the throwout bearing just touches the pressure plate spring. Tighten the top locknut toward the swivel until the distance between it and the swivel is 0.4". Tighten the bottom locknut against the swivel. The pedal free travel should not be 1-1/2".

______________

I cant remember fully, cause I went with Hyd. clutch. But isn't there two spriings, big one on clutch arm and smaller spring on peddle rod!

Larry: yep, that's the procedure I used, same as in the AIM for my '76.

______________

Dave, there is an "over center" spring on the pedal assembly for the clutch pedal. It's job is to pull the pedal all the way back up, AND, once the pedal gets about halfway down, it helps push down on it...to try to save your leg muscles. It is a pretty dang stout spring, too. Does your pedal just flop around if you take it loose from the Z bar? It shouldn't. It should stay all the way up. If you were to push down on it with the linkage disconnected, it would slam down on the floor after about 1/2the way down...and usually mash a few fingers in the process. I may have a pic/diagram somewhere...

______________

Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Ruh Roh.  It's floppy if the pedal rod is disconnected from the Z-bar along with the firewall to z-bar spring.  No spring action at all.  The engine has been out for the last year and the clutch pedal has just sat at the floor that whole time.  Guess it's not supposed to be that way.....

______________

Well..my memory has failed me...AGAIN... I should really start checkin stuff before I speak..
There is no over-center spring on the Shark cars...only the one pull back spring you mentioned, from the Z-bar to the firewall bracket. The earlier cars, with the Borg-Beck style clutch pressure plate needed the over-center spring...the later, diaphragm type pressure plates did not need it. My apologies....
So...if your pedal has too much free play, check to see that the rubber bumper/stop is still on the pedal bracket. It is there to keep the pedal from banging back against the bracket when you let up on the clutch. If it is missing, or damaged, it will give you more freeplay than normal. Other than that, it is just a matter of adjusting the freeplay out of it. This is where the different height fork pivot balls come into play, as well as different height throw-out bearings...


______________

Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Thanks, Joel.  Glad we figured that out!  I was doing some more exploring yesterday, it seems as if the new boot on the fork/bell housing is too stiff for the z-bar return spring to overcome it.  The rubber bumper on the pedal bracket is still there and a gentle pull on the pedal is enough to bring it up against it, but it won't ride there on its own.  What about a stiffer spring for the Z-bar return?  Or maybe an additional, smaller spring inside the main spring?  

______________

Actually, Dave....I think the longer pivot ball would make the linkage "tighter" than the short ball would....you're moving the fork closer to the Z-bar, basically. Not much, be some, and it does effect the geometry some.
The return spring on the Z-bar to the firewall bracket should be enough to pull the pedal back up...unless the thing is stretched, for some reason...and the constant up/down over the years might certainly do it. You don't really want to start adding more springs to it...unless you have really strong leg muscles!
I think my '74 pedal has maybe about 1/4" of "flop" right at the top, that the spring doesn't pull all the way back up, but...I've never looked at my rubber bumper up there, either...it may have a groove in it from the pedal bouncing off of it over the years...who knows? 1/4" is acceptable, as far as I am concerned, but your's sounds like it has quite a bit more than that. Even with all of the lower linkage disconnected(to the fork), that spring should be able to pull the pedal all the way up....something is just weird here.(besides ME)

______________

Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

I'll agree something is weird, and I don't think it's you!  I did some more investigation tonight and here's what I know:


______________

Well, I have to admit I tried the second spring route.  Went to my favorite local Ace Hardware (minutes from my house) and browsed their plethora of springs.  Picked one that was shorter and weaker than the main return spring and installed it inside the main one, both springs are installed in the same two holes.  Voila, the little bit of extra spring rate is enough to bring the pedal back full every time.  Yep, it's a little bit Bubba, but it works and it doesn't increase pedal effort too much.  I really think the only problem is that new boot on the clutch fork is stiff - maybe when it gets broken in more the second spring won't be needed.  

______________

Dave,  If it makes you feel any better, I believe that you can (sometimes) engineer a better process. Now................the next hurdle?

______________

If it works, that's one less problem! NOW you're an engineer!

______________
"Down on the Boardwalk...

(Click image to see a larger version}