Clutch in about 1,200 miles ago. After a gentle break-in, the release point started creeping downwards, until it was about 1/2" off the floorboard. SPEC suggested hydraulic system issues, so we replaced the slave (AGAIN), along with the master (and threw a DTE brace and hardened output shaft in - what the hell, as long as it was apart again). Bled the thing damn near to DEATH (including driving for a day, and reverse bleeding thru the "SickRick Custom Bleeder Extension").

Pedal is about where it should be now, but high RPM/WOT shifts @ redline yield a nice GRIND going into the next highest gear (1->2, 2->3, 3->4), as if the clutch isn't releasing. I'm also getting the "pedal not returning after high RPM shift" syndrome, although there is no slipping/burning clutch.

Sound like a bad pressure plate (or does the SPEC clutch just suck *****?). I HATE the idea of having to drop the drivetrain a THIRD TIME to replace the pressure plate, and at this point would almost consider going to an RPS or other high performance clutch.

A friend suggested there may be "centrifigal load springs" that keep the clutch from slipping (increase clamping power) at high RPMs/power that aren't letting the clutch fully release.

Need to make a decision/move soon, before I'm looking at tranny issues. Calling SPEC on Monday to see what they suggest (since we eliminated the hydraulics as a potential point of failure)...

Rick

 

Yea an adjustable master should would be nice. I have been running the spec 3+ now for a good while on my c6 shifting it at 6800 without any problems. And I am not nice to my vette when I drive. Did you guys use the shim. If not that could be your problem. I had to call spec 5 times to feel comfortable with the answer. 2 guys told me not to use it 3 guys said to use it. I was not happy that they didn't know for sure. I think that could be your problem though if you didn't shim it.

 

Yes, we put the shim in. How far off the floorboard do you start engaging in gear? Do you find it to be lower than the stock clutch? I was actually thinking of putting a second shim in. While the flywheel/clutch/plate fitment is the same as the C5, the different slave configuration has me thinking one shim may not be far enough forward. An adjustable master would only really adjust pedal height, not throw distance. Since it appears to be disengaging fine under normal (grandma) driving, it's got me thinking the issue is elsewhere.

As I said - we eliminated the hydraulics as the issue, by replacing everything (again - though we didn't do the master the first time). Though I wish someone made replacement stainless lines for the system, as the rubber lines GM uses aren't even rated for brake use. The SPEC 1-3 series supposedly don't require any more pedal pressure - as they claim engagement is fine for street use.

The stock clutch had plenty of meat left on it, and suprisingly for my power levels (542RWHP/572RWTQ) I never had a problem with it until the throwout bearing start crapping out. Figured I might as well do the clutch at the same time (47K miles), since it was 7/8 of the way apart anyway.

Any other SPEC owners that care to relate thier experiences?

Rick

 

Mine engages almost at the top. I thought the stock clutch engaged right off the floor. Sorry to hear about your problem. Until a new adjustable master comes out I think you may need another shim.

 

where again did you say it starts move ,right off the floor/ half way or high release? if a high release you can make a spacer so to limit travel, re. hoses did ya remove hose from slave and check for restrictor, ya should check all hose ends. there are more clutch tips in c6 z06