Clutch wont release

[resto65]

Some car info first

This is a 65 Mustang, car used to belong to the members Airride if you know them. I installed a 408W in the car with a Tremec 3550 transmission. I used a clutch pedal assembly which allows the use of a Fox body cable set up to operate the cutch system.

This worked flawlessly for 3 years. One day on a drive to a local car show, I pushed down the clutch pedal and noticed that something wasn't right as the clutch wasn't fully disengaging. I pulled over and was able to adjust the cable tension with the firewall adjuster (same as a fox body type set up) to get the clutch working properly again. This got me about 5 more depresses of the clutch pedal before it started acting up again. I took the car straight home as I figured that the cable had gotten burnt and was stretching. This car has a very tight engine bay with the 351W block in it.

I got home parked the car and immediately ordered a new clutch cable figuring that was the issue without question. New cable arrived pulled the old one out and noticed that there was no damage to it at all but changed it anyway. New cable is installed and adjusted and I still have the same problem.

Next step, Drop the transmission as now I figure that there must be bent fingers on the pressure plate. I have removed all the parts and I cannot find any issue visually with any part.

Is there a way to test a pressure plate to see if something is wrong with it? Could I have bent the Clutch release fork? The fork has a curve in the shape of it when new so its hard to tell if it bent. Does someone here have one that is known good that they could measure the arch of for me to compare?

I have ordered every associated part I can think of to fix this. New McLoud clutch kit, new Billet flywheel, new clutch fork, new pivot ball another new cable and even the retaining clip for it on the transmission. I am waiting for the parts to arrive but without finding a broken part, Its making me wonder if I am going to put it back together and still not work. I have even checked the end play on the engine to see if the thrust bearing went out and its within spec.

Anybody have any other suggestions?

Chuck

[Scrape]

I am sure that someone here on the board can help you out. Our resident expert ZR can probably chime in on this.

[ZR]

What we are seeing with cable style set ups on the early Mustangs, over time firewall starts to flex to the point the clutch will no longer release, suggest you start there.
Best solution, hydraulic set up from MDL or similar. We have a number of them out there with good results.

[resto65]

I looked at the firewall really well and don't see evidence that it has bent. I use the word bent because whatever caused this to happen put quite a bit of slack in the cable. Also the clutch fork would rest in the center of the bell housing opening where it sticks through for the cable to attach. This is when making contact with the throw out bearing only giving me about half the travel it should. I am hoping the parts I ordered fix the issue but I am going to look into switching to a hydraulic clutch set up, maybe this will also make the clutch pedal lighter to push. Only down fall is I will have to remove the power brakes.

I wont be able to really see how much flex is in the firewall until I put it back together and push the clutch, I just cant find a way to put pressure in the cable mount the same way the cable would while the clutch is depressed.

Thanks for your input on this,

Chuck

[ZR]

Most times you wont' see an actual bend rather the firewall deflecting once you apply pressure to the clutch pedal.

[ZR]

Set up we did on a 67

[ZR]

[ZR]

Set up looks like this.