First off, I haven't talked to Spec yet. I'm calling tomorrow since they're not open today. My car's been sitting for 2 1/2 months because I was frustrated, but I finally pulled the tranny this weekend. The car is a 2001 Z28, stock engine, bellhousing, and tranny. No LS2 anything. I posted about this a little bit here https://ls1tech.com/forums/manual-transmission/720584-who-else-using-spec-super-twin.html post #'s 46, 74, & 79 (I was angry on the last one, sorry) I also talked to Spec at the LSx Shootout and was told to measure everything and call them. They were much nicer then. After pulling my transmission for the third time, here's my story:

It messed up with 1,100 miles on it. The pedal got super stiff, I couldn't hardly push it down. When it would go down, the car would still move but the clutch slipped. I took it apart and found the throwout bearing messed up and the fingers on the pressure plate uneven - like something was stuck between the disks.



I unbolted it, didn't see anything and bolted it back up - The fingers were even then.



After I got a new throwout bearing, I measured the clearance that it had to the pressure plate: -1/8" (roughly) Which meant the t.b. was pushing in on the cluch 1/8". When you add the 1/8" air gap I need, it means I had to come up with 1/4". I made a 1/4" spacer to go between the trans and bellhousing and put it all back together.



I still had the same freaking problem. The car wouldn't go into gear with the clutch pushed in and if I put it in gear while it was off, it would take off when I started it with the clutch pedal on the floor. So, I thought hydraulic problem. It was a brand new slave so I simply replaced the master cylinder and bled the crap out of it. Same problem. This is when the car sat for a while. I pulled it apart Friday and saw the same thing I had before, with the fingers uneven. I unbolted it, didn't see anything wrong again, measured everything this time, and bolted it back up. The fingers were even again. My measurements:

Trans side disk .342"
Floater plate .316"
F.W. side disk .341"
Metal plate in diaphram .275"

The throwout bearing still measured 1/8" into the pressure plate. So that's where I'm at. I'd like to keep this clutch because everyone else who's gotten their problems fixed is having great luck. Hopefully I will too. I'll call them tomorrow and see what happens.

 

Just wanted to update everyone on this. I spoke with Donny and he is sending the unit back in to us for assessment. The fingers are definently unusual. But we will see whats happening and go from there. Thanks!!

 

You got here before I did. Thanks again!

 

Buy an LS7 clutch from SDPC and NEVER look back!

 

LS7 clutches are much more limited in the power they'll hold vs the spec twin.

 

Gee Robert...it seems that you are a bit of a broken record. No matter what the situation you have the same answer. This is a shame since a number of people on this board have cars that make more power than a stock clutch is meant to hold. At any rate...let me know if you ever need anything!

 

I noticed that too, lol. Maybe he's got stock in GM and needs to sell some parts for them. I don't think an LS7 would hold up to the abuse that I like to dish out. I had good luck with my first Spec 3 I had, so I went back to them for my new car. BTW, I shipped the thing out today so it should down in AL in a couple days.

 

Remember we will be out of the office from Dec. 21st until January 2nd. That being the case...these parts will not likely return to you unitl after the holiday. Let me know if you have any further questions. Thanks!

 

Problem solved! See here: https://ls1tech.com/forums/showthread.php?p=8618312