Hey all. Right from the start my clutch was grabbing and difficult to engage smoothly. It even created a wheel-hop effect most of the time. When I pulled it all out, this is what I found-



You can see the heavy contact on literally half of the FW and PP. The disc did not look unevenly worn to me when removed. What do you think was the issue here? FW was resurfaced prior to installation.

I've seen spots like that from the metallic particles in the clutch disk rusting while sitting. Then when you run the engine they scuff like that because the rust has penetrated both the flywheel and pressure plate. It doesn't take long - I had that happen in about a month's time.

As for wearing on one side only it could be from uneven spring pressure but it could also be because only that side of the assembly rusted - more moisture in that side of the disk - although why, I can't imagine.

Can that rust be "burned off" with a couple of good launches, or is the only cure a new disc and resurfacing of the flywheel and the PP?

I'd take a close look at the lever in the center of that wear. Bet you find a cracked lever or the pressure plate is cracked near it.

Not the first time I have seen a bad clutch assembly, whether rebuilt or new.. usually the pressure plate, but I have seen bad discs also..

Is the clutch disc a race disc or street and strip? The race disc don't slip very much, just like thier designed to do
That being said it may have to much pressure plate pressure for your application also to drive nice on the street Good luck Let us know what you find and do to fix it

The problem is only on one side of the plate. I would imagine it was a loose bolt or a problem with the PP.

A bolt broke on my PP several years ago. It caused similar symptoms and wear.

I've seen a few cracked B&B pressure plates. That's why I mentioned it.

Usual symptoms include poor or no release. The hot spots on the pressure plate and flywheel tell which is suspect.

I'll agree with the others, Seems like a Pressure Plate issue, Myself, I'd replace the entire assembly, Flywheel included.

a lot of times those hard [hot] spots on the flywheel can be blanchard ground to clean them up, but you don't really know how deep they go into the face of the flywheel. it will look good when done [ground], but if not removed entirely, will show up very quickly and the symptoms will return. i vote to replace the flywheel as well.

Yes, right In the center of the spots is that lever. Could be anything mentioned, broken bolt, something cracked, bad/weak spring, pivot worn, heights not equal.

Grind the flywheel. It is more than serviceable.

Normally when you see what you have, the finger height is off. What happens is as you push the levers down, one or possibly two of them are low to start with. The low finger or fingers do not let the disc get a gap from the flywheel.

See it all the time. It could also be a cracked cover or lever, but the result is the same. No need to replace a bunch of parts that are still more than good enough.

FWIW I never ever install a pressure plate without checking finger height. Should be done because humans make mistakes.

The whole setup is being replaced. McLeod flywheel and dual disc package. Thanks for the great input. The flywheel I already sold... the PP is long gone. I blamed everything on it from the get-go.

You all missed the mark on this one. It's the basics of manual transmission. If you guys were real technical support people you all would have pink slips.

Before installing new parts the bell housing needs to be inspected for cracks and checked for run-out and squareness while bolted to the block and all fasteners torqued to spec.

well, i'm not caring if i get a pink slip or not [i'm retired], but just how many transmission assemblies [clutch, pressure plate, bellhousings] were dialed in to be true at the original assembly plant ? now you are correct the parts in question need to be inspected for cracks, burrs on mounting surfaces, bolt torque, etc. but over the years i have ran into problems with clutch discs and flywheel/pressure plate chattering. in all but a couple instances, the only way the problem was fixed was replacement of clutch parts. no dial-in of the bell was done. i am very well aware of the importance of the dial in process and the need for parallelism of the mounting surfaces, but there are more cars out there running just fine without those checks being done than those that have. when replacing parts these days however, care must be taken to insure there are no burrs on mating surfaces, and things such as pressure plate fingers are even heights and throwout bearing flanges are not dinked up. aftermarket bells need special attention. back in my day, however, replacement parts were of better quality than those available today. the OP asked for advice and all i could give is what i have ran into in over 50+ years of playing with these things. i make no claims about me being the only "super genius" in the land and a person should not listen to anyone else's experiences or expertise. you have valid points, and one could and should check these things. but to have us all "fired" because we state our life experiences is just a little course. it just kinda rubbed me the wrong way. i apologize if i have offended you.

A friend of mine was describing the same issue he is having with a Chevy he is building. He has owned and built many cars in the 50 plus years that I have known him. America symptoms as yours. He has a Zoom clutch and pp. He had the flywheel turned at a reliable machine shop. He was planning on replacing everything. Is yours ok now?

OK pink slip, what are the last three words in my post above??? Thanks for your deception!

While I don't discount the need to check components, torque to spec. etc. I am curious as to how a misaligned bell housing would result in that wear pattern. If it were that far out of center or parallelism there would be other issues IMO.

Yep, off center bell or not parallel would cause oodd wear ALL AROUND the flywheel. Just basic physics.

This is extremely localized wear.