Hitechzo6

2002 ZO6 408" dry-sump. 558 to the wheels. Running a spec II clutch with a lightweight flywheel. Going down the long straight at Brainerd this past year, the clutch WOULD NOT dis-engage. Also wouldn't let me shift to the next higher gear. I could literally step on the clutch (good pedal pressure) and the motor does not come to idle, it would just start engine braking as if all i was doing was taking my foot off the gas. Once the rpm comes down it would shift fine. Had the clutch bled before the next event. Next event the clutch didn't want to work at high rpm's (7200). Plenty of peddle, just didn't want to shift up or down.

I was told that the clutch fingers may be "distorting" from the sustained high rpm, and not fully dis-engaging. The clutch has been bled numerous times, and never does the "stuck on the floor" thing. I want to up-grade the clutch, but I'm not sure what to fix, or go to.

RAFTRACER

Sounds like typical clutch hydraulic issues to me .........I have the same clutch assy in both of my cars (w/lightened aluminum pressure plate and flywheel ) and have the same shift points as you are mentioning...........
Is the clutch new ???? Is the clutch enagagement point ( at the pedal) close to the floor, or closer to the floor than was stock. I have seen some clutch disengagement problems when the clutch assy is installed without the shim behind the clutch actuator cylinder. I have also known a few to need the McLoed hydraulic master cylinder which has 1/16 larger bore diameter. If I were you before disassembling your whole car , I would try the McLoed master cylinder. The master will create more travel at the hydraulic actuator, releasing the clutch disc sooner. ......If the clutch pedal engagemnt hieght is close to the floor than stock, try the master. My '03 Z06 has a SPEC stage 2+ disc and it needed the master cylinder for proper operation. My '02 Z06 has a stage 3 disc and did not require the master cylinder. The McLeod master cylinder is a little hard on the wallet ....($300.00)...yooowwch!!!

Hitechzo6

Thanx. I'm gonna try the McLoed master. On a side note, I don't know if you remember me, but I'm Brian Enochs. My dad Ed had the black 94' LT1 car with the heads and cam. You actually put a clutch in that car for us years ago when we were living in Ohio. Met you at an auto-x. Living in MN now. Don't ever come here...it blows.

gpm30236

Raftracer has lots more experience than i do, But have just taken the SPEC3+ clutch and lightened flywheel out of my car had no shifting issues, but the steel heat band had warped fairly significantly , you can see this when you take the dust cover off the bottom and inspect the clutch, all the plates are not even, . When i got it out the flywheel itself was also warped. might be worth doing the check, Take off the flywheel and turn the engine over by hand. Inspect very carefully to make sure that all the discs are evenly spaced completely around the pressure plate.

RAFTRACER

Hitech......you have a PM

Gary2KC5

I had a Centerforce dual friction clutch once that wouldn't dis-engage at high rpm's.

I also had a spring from a SPEC stage III friction plates come out and get jammed between the clutch and it...again wouldn't dis-engage.

Joe_G

Lots of us guys who drag race have this problem. I've been very lucky changing out the fluid in the clutch master every couple of weeks (it gets black in a couple of weeks) as proposed by member Ranger. He swears by the technique and has not had any clutch problems nor have I on my C5 or my C6.