I didn't want to hijack the other Clutch thread so here's my problem: Just installed new Spec Stage II clutch and aluminum flywheel along with new master and slave cylinders. Symptoms: Clutch engages within first 10mm of travel, then a whole bunch of free travel in the pedal. Very difficult to shift and lots of noise. Air trapped in the line or could the clutch be in backwards? (It came pre-assembled). I hate thinking about dropping the engine again just to check.... Bummer.
When you say the first 10mm of travel, is that 10mm from the floor up, or 10mm from the top of travel down? Assuming the former (clutch engages with the pedal very near to the floor) it could be air in the lines. The clutch slave is notoriously picky about how its bled.
It's likely (depending on the thickness of the clutch center flange, that if you got it backwards, you would blow out your clutch slave. First check the slave for leeks. grab the boot and pull it away and check for moisture. If it's wet, replace it. If it's dry, try bleeding it with a pressure bleeder. Take your time and cycle fluid several times through the system. Also, if you do need to remove the trans, don't do it by pulling the motor: that's way too much work. just separate the trans from the motor and lower it out. It's easier if you drop the subframe first.
Clarification on the engagement point please. If weak pedal to near the floor, suspect air in the line, as Mike explained. If engagement is at the top/first bit of pedal travel, suspect mechanical cause. Installing the disc backward on a Spec disc wouldn't cause this much problem, but if the release bearing isn't on the release fork properly, it would. As Eric suggested, this is the first thing you do. In rare cases I've had air enter the master requiring a few extra bleeding steps, but first inspect the slave and re-bleed.
Just a quick follow-up: All it took was a few minutes with someone who knew how to do the pressure bleed. Good to go. I do notice that there is more noise/vibration off-throttle which I'm assuming is because of the single-mass flywheel, no?...
Yes, the single mass + SPEC clutch (or for me, any clutch with my old Fidanza flywheel) is much noisier than the OEM unit. Most of the noise comes from the gearbox itself.
I am having the same issue, clutch engages about 10MM off the floor, returns to the top normally. Time to check the boot for a leak. Haven't had anything apart, so wondering why there would be air in the system.