I have a stamped steel clutch fork for a project I'm working on (65 vette). I'm concerned about it holding up to drag racing abuse. What so you guys think of me plating the backside of the fork with plate to increase the strength.
I had to do this on my Mustang. I welded two pieces 1/8" flat bar along the inside edge of mine to keep it from bending again. Worked great. Still holding up after 30 years.
I usually wait until there's a problem, before I fix it. But hey, you can do whatever you want! Hopefully the welding won't affect the heat treat too much in the area around the pivot ball, which you can't really box fully, and which has the most stress on it.
There are early Chevrolet’s that are forged and don’t have a problem. Different end however, but easily overcome.
I'd drill a hole through the plating material for the pivot ball to pass through, rather than have two separate pieces of steel stock, to lessen the stress at the pivot ball and help compensate for the heat of the welding. Make sense? Like someone else already mentioned, there's early 50's Chevrolet cars and trucks that use a forged steel arm that may work for you also. I am Butch/56sedandelivery.
I'm with @squirrel on this, I think welding that heat treated part could damage it. unless you anneal the part then weld your box section using the same grade steel the part was made with and then getting it heat treated to the same level as it was originally.
One other consideration (outside of the idea that I do also believe in not fixing something not broke). Clutch forks are relatively cheap. An original clutch fork on a 65 Vette is probably worth many times what a newer one costs. Experiment on the new one. Clutch forks seem to hold up under quite a bit of abuse though.
It depends on the pressure plate. If you are using a diaphragm pressure plate no reinforcement should be needed. If you run a really stiff 3 finger pressure plate your cross shaft or linkage rod will bend before the fork will. We used to have a clutch shop in Detroit build our pressure plates and the rod from the pedal to the cross shaft had to be changed out for a larger rod and the cross shaft had to be braced to keep from tearing the factory welds. The rod to the fork had to be beefed up , but we never had a problem with the fork. You could tell the guys that ran their pressure plate . Their left leg looked like a body builders leg and the right leg was normal. I had to brace my fork when I built my Morris minor Gasser, but that was because I had cut it in two and lengthened it to get the right release when I used a cable clutch and a Fox body mustang clutch setup with my Lakewood scattershield.
I think the original GM piece is fairly robust and I have never seen one fail . I’m sure some have,,,,,,but I’m with thinking that welding will do more harm than good . Don’t go looking for problem that is not there,,,,,if it ain’t broke,,don’t fix it . I’m certain that there are other things more important than that to beef up . A 65 Vette in a drag racing setting will need a few things looked at,,,,but,,,I always look at the weakest link in the chain first . That’s just my reasoning . Tommy
Exactly what I’m talking about,,,,I had that happen years ago in an old street application. I was hard on it,,,,,,there are many weak links that can fail before the clutch fork in my opinion . Tommy
When I fabbed the clutch linkage for my coupe I used a Corvette z-bar and fork. That z-bar is better, the levers have 360* contact with the cross tube and I preferred the Corvette fork with it’s mechanical connection instead of the rod and pocket held together by the return spring.
How high the horsepower and how stiff a clutch are you using? Chevy put the stock stuff behind the L88 and put a 12 month warranty on it. D
I am in the camp of " I did it and it's lasted for years" BUT it was done because I had to play with the length of the arm, made longer to make up for the monkey motion getting to it...…………………………..
How about changing the clutch itself. Smaller diameter double and triple disc have almost no pedal pressure and hold a lot of hp. We use a triple 7” with standard appearance transmission with no problems at all starting and driving from a stop.
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