C1 Clutch adjustment

[Richard M.]

Re: C1 Clutch adjustment

Jerry, good catch.....Here it is: https://www.forums.ncrs.org/showthre...-bar-alignment

Looking at David's photo in the above link, and the description, it's obvious the fork is too far forward. The clutch pedal rod is not connected, and the gorilla spring lever end of the Zbar is not pointing slightly forward as it should. The spring can look that way on either side of the high point/over center "arc" of that lever.

Now I'm wondering if the bell housing fork "Pivot Ball" is too long. ???

Maybe the original clutch was a pass car "flat finger" type, and they used the 1 1/4" TO bearing, and made up for it by installing a long BH fork pivot ball stud. ???

Rich

[Jerry W.]

Re: C1 Clutch adjustment

comparing Dave's gorilla spring hook up with the swivle link of the z-bar..... the long end of the spring as it exits the main body of the spring is on the top as opposed to exiting the main body of the spring on the lower side of the main body ...it just doesn't look right.....Just saying

[Richard M.]

Re: C1 Clutch adjustment

comparing Dave's gorilla spring hook up with the swivle link of the z-bar..... the long end of the spring as it exits the main body of the spring is on the top as opposed to exiting the main body of the spring on the lower side of the main body ...it just doesn't look right.....Just saying

Jerry, interesting observation. I just checked another '59, mine, and it is just like the other '59 I have here(pic above), with the bend coming off the lower side of the main spring coils. Both of these '59's springs are originals, and the bends are just the opposite of David's in that early picture from 2011.

Rich

[David H.]

Re: C1 Clutch adjustment

OK, let's see...
With all your suggestions (thank you very much) I realized two things.
First, the clutch fork was not in the correct possition on the T/O bearing. Picture one.
Removed the boot and moved it closer to the bearing. When I tried to do this it fell right into place. Picture two.
The other thing I found was the clutch pedal was too low so I cut the rubber bumper at the top of the pedal so that it was more even with the brake pedal.
These two thing have gained me the distance I needed to at least get the rods connected and some free play at the pedal but no adjustment left in the rod.
However, when I connected my gorilla spring all the free play went away and the pedal will not return from the floor on it's own.
But I'm gaining on it! !@#$%^&*!clutch linkage 7-12-12 001.jpgclutch linkage 7-12-12 004.jpgclutch linkage 7-12-12 005.jpg

[John H.]

Re: C1 Clutch adjustment

However, when I connected my gorilla spring all the free play went away and the pedal will not return from the floor on it's own.

David -

There's an adjustment for the angle of the bolted-on bracket on the top of the Z-bar that sets the over-center point where the system changes from a return spring to a pedal assist spring; it's in the ST-12.

[Dennis C.]

Re: C1 Clutch adjustment

David,

Glad you are getting closer. Next, Look in the ST-12 for the over center adjustment. After making that adjustment, redo the clutch adjustment.

Dennis

[Philip P.]

Re: C1 Clutch adjustment

There is something that does not look correct in the picture of the throwout bearing I cannot put my finger on it may be the angle, I just installed the same clutch in a 1960 and following the ST-12 all worked well.
throwoutbearing2a.jpg

[Richard M.]

Re: C1 Clutch adjustment

David,

Please take a photo showing the assembled rod in the Zbar lever and where it connects to the fork. In particular the angle of the fork as it comes out of the BH. Without the boot installed. Like my first pic in post #13.

Is it possible you have the wrong fork?

I see the angle of the end is different(pointing more forward) on later 64 up forks. Pics below from Zip Website.

1955-1962 Fork


1964-1981 Fork

[Richard M.]

Re: C1 Clutch adjustment

Mine is the top, yours is the bottom(from your 2011 thread). I see the forks are obviously different at the ends. IMO your fork is wrong.

Mine.jpg

Davids.jpg

[Ronald W.]

Re: C1 Clutch adjustment

From the photos it looks like you have the original type flat faced throwout bearing. You are using a diaphragm type pressure plate used in later model Corvettes that requires a round faced bearing. These bearing come in different lengths. I found the longer of the two i have worked in my 61.

[David H.]

Re: C1 Clutch adjustment

I reviewed the items I purchased for this and here is what I found:
NOS clutch rod swivel 3716807
NOS clutch lever 3723603
NOS clutch control engine bracket 3723603
NOS clutch lever Z bar 3732881
NOS clutch fork rod 3739045
NOS clutch fork 3739043

Are any of these NOS numbers incorrect? Like the fork?

[Richard M.]

Re: C1 Clutch adjustment

David,

The fork 3739043 is the 1962 fork and service replacement for the 55-61's.

The number is good, but is it possible that your fork is not that number, possibly mislabeled? They didn't stamp part numbers on the forks.

Another identifying feature is the width of the arm. The 55-62 forks are narrow, whereas the 64-81 are much wider. See post #2 of this thread.

I don't know about the other numbers, no books in front of me right now.

[David H.]

Re: C1 Clutch adjustment

clutch linkage 7-13-12 002.jpgclutch linkage 7-13-12 001.jpgRichard, the pictures you asked to see...

[Jerry W.]

Re: C1 Clutch adjustment

gorilla spring.jpgIt's unfortunate that the pictoral of the Z-Bar and Gorilla spring assy in the ST-12 does not represent the 58-62 models.

here's a pictoral from CC catalog.

[Richard M.]

Re: C1 Clutch adjustment

David, Ok, Here are your pics, and my pics for side by side comparison. When I click through each photo comparing mine to yours, I see a big difference in the angle of the end of your fork.

The end of the fork on mine is about at the rearward bolt of the engine Zbar bracket. The end of the fork on yours is at the forward bolt of the engine Zbar bracket. It sure looks like the angle of yours at the end is not right.

Your Zbar position looks right, you have the correct 9 1/2" rod, so all that's left is the fork. Either it's the wrong one, or it's bent(which I doubt), or it is not located in the Bellhousing properly.

I don't know what else it could be.......Rich

Mine #1
Mine1.jpg

Yours #1
yours1.jpg

Mine #2
mine2.jpg

Yours #2
yours2.jpg