I just broke a fork in my 951 with a KEP Pressure plate.

This is the fork we took out.

http://farm3.static.flickr.com/2276/...449b4bc4_b.jpg

We heat treated it and TIG welded it back together with additional material added around the area that broke(more than twice as thick). Then ground it down to fit in the housing. Not the prettiest prototype repair.

http://farm5.static.flickr.com/4024/...2c40f78b_b.jpg

Fork has only been back in the car a couple of weeks.(Thousand miles maybe at this point, lots of stop and go to) Shifts better than it ever has!!! My original fork must have had a slight bend to it before eventually breaking.

Correct me if I'm wrong but the clutch forks are cast Steel and not cast Iron.

Even on cast steel or cast iron the control of strength is in the quenching/cooling after the heat process. Shortly after the eutectic stage (molten to solid) if the item is quickly quenched (even ice water) it will be very strong but sometimes brittle. If one waits about 20 seconds after the heat process to quench the part, in 60 deg. F. water, it will be strong and also tough. If the heated item is allowed to cool in moderate air temp. the item will be soft and mailable (Exceptions in Cast Iron here).

All of the above depends on several variables - heat range is a major variable...

It did not weld like cast, FWIW.

The clutch forks could be forged? There again the broken area is now welded and treated as a weld joint. A good deep penetrated weld joint can be as strong and tough as forged, if treated correctly.

I had my clutch fork brake on my track car running a SPEC stage 2+ clutch, I notice there was some rub mark on the fork. I cut a big window in an extra bell housing so I could get a good look at it in action I found the pedal was traveling to fare and the release bearing was rubbing the fork. I made an adjustable clutch pedal stop and have had no problem since this will be my second year racing on it.

Cast steel is something I really know nothing about. Looks like the stuff they call "pot" metal where the 2 pieces broke apart. But since you can't weld that sh-- I mean, stuff, it can't be that. But I dunno, maybe it CAN be tigged. Could someone send me a broken one so that I could try a nickel stick on it to see if it works? I will post the results.

I'm baffled as to why you did not also "fix" the unbroken side before it has chance to bend or break?

We did both sides. Just doesn't look like it in the first picture I posted.

http://farm3.static.flickr.com/2747/...5c09b569_b.jpg