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View Full Version : Welding/fab experts, need some help.



Xtremjeepn-Cole Ford
April 11th, 2010, 08:26 AM
This is for a race/street car.

My pressure plate on the clutch puts too much pressure on my clutch fork. So the fork breaks. This is a common issue on these cars and there is NO upgrade available.

Possible to just weld tabs to the outside of this fork to reinforce it?

A "new" fork is $400. Used from around $25. These are a MAJOR pain to get to on these cars. So I want something that should last.

http://farm3.static.flickr.com/2179/4509144592_53b1f06344_b.jpg


http://farm3.static.flickr.com/2276/4508503781_03449b4bc4_b.jpg

BradC
April 11th, 2010, 08:41 AM
Do you know what it is cast from? I'm sure it could be welded fine. is there enough clearance on the outside forks when it is installed?

If there truly are NO aftermarket versions available this is your chance to get it into a cad program and go to market with your own! Do it Cole, this is your chance to make millions! :D

bowtied1
April 11th, 2010, 09:32 AM
Welding will depend on what the steel mix is in the cast of your fork. My suggestion is see if the expensive replacement is a hardened material and forged or stamped. Remember welding will generally yield mild steel for strength. you would have to temper it to make it real strong. There may be a reason the replacement is $400. I would check with On Track and see what they may have available in a heavy duty.

Xtremjeepn-Cole Ford
April 11th, 2010, 11:12 AM
"On track" won't have anything for this car.

This is a 1986 Porsche 951.

NismoFreak
April 11th, 2010, 11:47 AM
This is a complicated fix mostly because it looks like a cast part. I almost guarantee I could fix it with a mig welder, torch and a lot of grinding. It would be better to fix it with a stick welder and the correct rod but i'm not much of a stick welder kinda guy. If metal could be added to both sides and the back you'd have an easy fix. If metal cannot be added then you'll need to have the fork made by a
machine shop.

smokebomb
April 11th, 2010, 03:23 PM
Anyone with a CNC mill should be able to make that out of billet for you. Shouldn't cost $400 but it would be close. But you wouldn't have to worry about breaking it again.

tantonio
April 11th, 2010, 09:30 PM
"On track" won't have anything for this car.

This is a 1986 Porsche 951.

The "Porsche" guys don't have a fix?.....if it's common as you say you'd think there would be someone who's addressed it with an aftermarket option....

Big Dave
April 11th, 2010, 09:33 PM
It looks to me like the part is designed to have the load evenly dispersed over those two ends. Have all of these common failures occured on the same side of the fork? Just thinking that maybe it's more of a sympton than the actual problem with some uneven forces being applied?

boost_junky9
April 11th, 2010, 10:43 PM
if its cast iron you will want a high nickel rod for smaw (stick welder) and preheat it in a oven to about 300 degrees for a half hour then weld it. Then let it cool down very slowly over a couple hours in the oven also if possible step the temperature slowly. You should be able to weld on some plate gussets when you weld it back together. If its cast steel i don't have any advice havent mess with it and don't have any advice but i can ask my welding teacher. I can't tell from the picture. With cast iron preheat and post heat are the only way other wise it will just crack in a diffrent spot.

Xtremjeepn-Cole Ford
April 12th, 2010, 09:01 AM
The "Porsche" guys don't have a fix?.....if it's common as you say you'd think there would be someone who's addressed it with an aftermarket option....


No one has addressed it. They just change out forks when it happens. This is for a relatively small number of cars. There were only 25,000 made world wide. Only 12k of those came to the U.S. This was all 20+ years ago.





It looks to me like the part is designed to have the load evenly dispersed over those two ends. Have all of these common failures occured on the same side of the fork? Just thinking that maybe it's more of a sympton than the actual problem with some uneven forces being applied?

No. Some forks break off both, or the other side.