Team Camaro Tech banner
1 - 6 of 6 Posts

·
Registered
Joined
·
1,009 Posts
Discussion Starter · #1 ·
File this thread under the heading of "Simply FYI". Might possibly help with confusion for someone else.

From my Engine thread:

Larry is that the clutch fork you have been using? Be advised that’s a second gen and unless modified likely interferes with the toe board floor on a 67.
All I can say for certain is that that fork has been on the car for the 25 years that I have owned the car and near as I can tell it has functioned flawlessly.

It does not contact or interfere with anything.

The car was converted (I don't think it came with a 4 speed) prior to me purchasing it from the previous owner's Widow. I'll admit though, there have been things about this car that have proven to be mis-matches. The clutch (frame side) bell crank bracket was one of them. The one pictured there is the correct one and is now on the car.

In another post you might have noticed the car has a 1962 T10-1C transmission.

Then there is the odd-ball stuff I have done to it myself. ;)

This is the clutch fork in question.
IMG_2845[1] by Larry Madsen, on Flickr

I later responded with this:

Larry is that the clutch fork you have been using? Be advised that’s a second gen and unless modified likely interferes with the toe board floor on a 67.
Well, well ...

Turns out you are correct. Another expedition into this car full of mismatches.

Noted earlier, I had dents in the firewall. I went through straightening out the dents.

I had some dents down in the area of the clutch fork and I did not make the connection at the time that they were there because the clutch fork needed the room.

As I reassemble now the clutch fork does not have room to operate. The top edge of the lever quickly hits the firewall. I can see where this would create a "twisting" motion of the fork ... which would explain why my throw-out bearing retainer spring was broken when I removed the fork.

I have a fix underway to clearance the area behind the clutch fork. This fix also solves another problem.

That problem is the gas pedal does not hit the floor before the throttle arm lands on the firewall in the engine bay. if the gas pedal is depressed beyond this point to the floor it creates excessive (binding) stress on the linkage/shaft connection for the throttle arm.

The clearance on the engine bay side for the clutch fork creates a hard stop for the gas pedal inside. Two issues solved with one fabrication.
--------------------------------------------------------------------------------------------------------------------------------------------------
Jump to today.

In a search I am finding this one is probably the correct one.
555-79729 by Larry Madsen, on Flickr

It appears to me the one I have and have been using is a heavier duty more durable fork. By the time I figured out there really is a problem I had powder coated the fork, purchased a new retainer spring and replaced the broken one ... Not to mention it was now installed in the car. Taking all of this into account, there is no way I am spending additional $$$ on another fork (especially one that might be weaker) taking the car apart and swapping forks.

It was not a terribly difficult task to "clearance" the firewall to allow space for the clutch fork to swing freely and fully.

This was the first phase:

It's a flat piece of sheet metal rolled/bent at the top so it can follow the slope of this part of the lower firewall. It's formed and installed like an inverted shelf. It's the top side of the fork that has no room to swing rearward.

Still looking a bit rough.
IMG_3283 by Larry Madsen, on Flickr

I had mentioned the gas pedal and linkage had some issues.

The throttle arm/lever in the engine bay would hit the firewall while the gas pedal still had more distance to move toward the floor.

This connection point at the pivot was in serious stress if a foot tried to push the pedal all the way to the floor.
DSC_2850 by Larry Madsen, on Flickr

The modification to make room for the clutch created a stop/block inside for the gas pedal.
IMG_3282 by Larry Madsen, on Flickr

With some soundproof wrap, carpet and the pedal floored ... the lever out in the bay can no longer hit the firewall.

DSC_3115 by Larry Madsen, on Flickr

I still have plenty of throw to actuate the carburetor.

PIC of the final result behind the clutch.
IMG_3314[1] by Larry Madsen, on Flickr

Some might refer to this as just another "Hack Job".

What I can say is it solves two issues and it cost me "Zero $$$"
 

·
Premium Member
Joined
·
1,821 Posts
I have one of these "incorrect" forks my '67 Camaro and I like it. The extra length gives it more leverage for a lighter pedal and better control. I modified the fork so it won't hit the firewall.

Here is a 1973-81 HD fork next to the correct first gen fork. All I had to do was remove some metal from the arm of the HD fork to prevent to prevent it from hitting the firewall. I installed this modified fork several years ago and it works (and fits) great!





 

·
Registered
Joined
·
1,009 Posts
Discussion Starter · #3 ·
I have one of these "incorrect" forks my '67 Camaro and I like it. The extra length gives it more leverage for a lighter pedal and better control.
Thanks for the comparison PICs.

I assumed the one I/we have might be longer.

I agree it would make the pedal more foot friendly. I converted to Borg & Beck clutch, so that could make my clutch a bit stiffer than most.

I also converted to the hemispherical end joints in my linkage. I had done that on a car in the past and liked the results ... smoother and tighter. By tighter I mean more responsive with zero slop.
 

·
Registered
Joined
·
76 Posts
I put a throttle stop on my carb. So I can’t push the carb linkage past wide open. I can still I guess, bend the pedal but I can’t trash the carb cause of the throttle stop. It’s off a nascar carb from eBay.
 

·
Registered
68 Base Camaro 355 Offy crossram Richmond Super Street close ratio 5 spd ivy gold 92K SoCal car
Joined
·
3,044 Posts
I fought with clutch fork travels 25 years ago on a 68 Camaro. Hot Rod magazine Sept 97 had a great article titled "Linkage Liason" The Right way to Adjust Your Clutch. Best article I have read. Basically they want the clutch fork parallel to the flywheel when fully released and Z-bar pointing straight down. The dimension from back of engine block to top of fork pivot ball = 4.75" on GM bellhousings. If you have aftermarket scattershield it can be as much as .100 deeper and even deeper if using the block plate. Flywheel thickness also affects clutch fork clearance. GM is .960" thick measured from crankshaft mating surface to clutch plate mating surface of flywheel. After market can be another .200" thicker. A thinner flywheel moves the bearing forward and the fork outboard end towards the firewall more. GM also offers 2 pivot balls. Short 1.48" and long 1.78" truck typically used the long and is .300" longer. The car short pivot on a scattershield postions the fork much more likely to hit the firewall. Mr. Gasket 15501 adjustable pivot ball can only be adjusted to 1.58" and doesn't help much.

There are many things that can cause the fork to hit the firewall.
 
1 - 6 of 6 Posts
Top