Reply to "Photos of the -1 clutch disc?"

Nate,

Good to hear from you again!!!!

After looking at your pictures, and having FRESHLY spent a couple of nights with slide caliper and various pieces of straight edges, and all the clutch parts and engine, AND ZF, I was able to get a pretty good read on what is needed to see if your shiny new parts will fit in your car!!!

It comes down to such minutia as how thick your flywheel is, because shaving your flywheel will move your pressure plate center hub closer to the pilot bearing adapter!!!

Looking at the pic of your old adapter, AND the picture of your old clutch disc, which is definitely WRONG(!), I would surmise that your disc hub was in direct contact with the pilot bearing!!! Check it out!

I plan on writing up a doc to post either in POCA mag or online...or both. But there are two crucial measurements to keep in mind!

1) the distance from the front of the splined area of the ZF input shaft, to the pilot bearing adapter: Mine calculates out to about 0.116" or just shy of 1/8" which is plenty! This will still allow about 0.300" of engagement of the ZF input shaft nose into the pilot needle bearing! (bearing is .470" wide)

2) the distance from the center hub of the pressure plate to the pilot bearing adapter. You will notice that the McLeod from Wilkinson is shaved WAY down on the flywheel side. There is probably only .040 to .050" from the main center plate of the disc to the top of the remaining center hub.

This second measurement is VERY tricky in that a shaved flywheel, or perhaps aftermarket, and a worn or thinner clutch friction surface will allow the hub to be closer to the pilot bearing adapter.

A spacer behind the flywheel (does anyone make these?) would fix this too....or perhaps give one a little more room to work with!

My calculations look to be about .050" or so of clearance. As my friction disc wears out, I have about .045 of clearance before I hit the rivets.....so my configuration is pretty close! (I am running an aftermarket alum flywheel, custom dual-sided Kevlar disc, and a stock Ford three finger pressure plate.)

I hope to check this all out with clay before I drop all the bits back into the car!

If you remove the metal block plate behind the flywheel, this makes it even worse by .075", so run a block plate!

These are all measurements with my Goose parts, and there is a suspicion that Panteras may have had two different length shafts in their -1 gear boxes!!!!

Again, I will post all of this somewhere with my drawings, measurements, and calc's, but I have been over it three times now and I think I found all my mistakes now!

We also found that the disc that was chosen has an issue with the pressure plate contacting the outer row of center rivets...about 30-40% of the width, so I will be putting a bevel on the inside diameter of the pressure plate contact surface. There is no friction disc contact there so no sweat losing a little metal.

I want to see if I can come up with a "Ford" disc that will fit the available kevlar linings and have a few of these discs made up. I really like the smooth engagement and the minimal wear on parts! Instead of 10" they come out to 10.5" which still fits the stock pressure plate just fine!

I just need to get away from the current (probably Chebby) pressure plate blank that was used! I will be fine with it but next change would want to change it to a drop in piece!

Ciao!
Steve