[Driftin_AW]

I recently installed a new carbon/kevlar clutch disk, I already had an upgraded pressure plate. I had barely finished running it in when I had to pull the engine to fix the headgasket. Now, it looks like the clutch is gripping more on one side or something, as you can see in the picture half of the flywheel and the adjacent part of the pressure plate have some big heat marks on them, and the other half looks brand new! Any ideas why this could be happening? And should I be worried?

 

[califcarm]

I would only be worried about those bare toes in the corner of the picture! JK

Did you not install a new pressure plate also with the disk? I have only changed them as a set before.

I would worry if it were an organic run-of-the-mill disk making heat marks so quickly like that, but I am not sure if that is abnormal for a carbon/kevlar disc.

Can you see if there are any hair-line surface cracks in the heat scortches areas?

Hopefully some with more experience with this clutch disk can answer.

 

[Driftin_AW]

well the reason I only replaced the disk was that when I did the engine swap I installed a complete heavy duty clutch kit that had around 10,000km (6,000miles) on them from my Celica. The old disk was pure kevlar, and foolishly I cleaned the flywheel with CRC prior to install which left a residue that completely destroyed the friction material. I wasn't going to replace a perfectly good pressure plate, so I took the advice of the clutch manufacturer who made the disk for me and sanded the flywheel and pressureplate to de-glaze them, then cleaned with MEK and installed. I will have a look for cracks while I'm working on it today.

The barefoot thing is starting to become a bit of a trademark of mine; about 50% of the pictures I've taken recently have included my toes

(The author of this message does not imply any affiliation with NoShoes Speed Works)

 

[MR2000GTE]

Are you sure you seated the PP fully against the flywheel?

I wonder if you might have ground the PP and/or flywheel unevenly when you sanded it?

One thing I've learned over time: never cheap out on clutch stuff, it always bites you later.

 

[Driftin_AW]

I sanded it quite lightly, wouldn't have removed anywhere near enough material to make the surfaces uneven.

Reusing an item like a pressure plate with only 10,000km on it isn't 'cheaping out', that's nowhere near enough driving to start wearing it to the point that it's unusable.

I might leave it for now and see how it goes. Although it's a PITA to do the clutch, I can have the engine out of the car in just over an hour so if I have to replace it then it's no biggy.

 

[CAPTN]

This is one of my main complaints against Kevlar compounds. They take forever to break in and they retain heat longer than other materials. This means that unless you give it suffecient time between runs, they will glaze the flywheel.
It is entirely possible that the heat has warped the surface of the flywheel and also possible that the pressure plate is applying uneven force to one side. The later is more likely. I would take the flywheel to a machine shop and have it measured for an even surface. If it's even slightly warped, have it center ground flat again. I would be sure to replace the pressure plate no matter what though.
Tyson