NEW SPEC 2 Clutch SLIPPPING!!

**JER-SS** · 07-21-2008, 06:29 AM

Hi I just installed a new SPEC 2 clutch in my 98 Z28. I used the shim in the kit to shim the slave cylinder and everything seems to be shifting OK but it slips under medium acceleration. I just finished the install yesterday so I only have about 20 miles on the clutch. Could this be a normal part of the break in or do I need to go in and take out the shim (possibly not engaging fully)?
FYI I changed the pilot bearing, throwout bearing, pressure plate and clutch.
Please help cause I really don't want to pull the tranny again without knowing for sure what the issue is.

**Wesman** · 07-21-2008, 08:43 AM

Originally Posted by JER-SS

Hi I just installed a new SPEC 2 clutch in my 98 Z28. I used the shim in the kit to shim the slave cylinder and everything seems to be shifting OK but it slips under medium acceleration. I just finished the install yesterday so I only have about 20 miles on the clutch. Could this be a normal part of the break in or do I need to go in and take out the shim (possibly not engaging fully)?
FYI I changed the pilot bearing, throwout bearing, pressure plate and clutch.
Please help cause I really don't want to pull the tranny again without knowing for sure what the issue is.

It is not normal for the clutch to slip at all when it is fully engaged. That will cook the cltch disc lining and possible warp the flywheel and cause clutch chatter.

Did you make sure the flywheel was 100% clean when you put it in?? They generally ship with a coating of oil on them so that they don't rust, so you need to clean it with brake cleaner to get rid of any residue.

Sounds like the shim might be preventing the clutch from fully engaging, there no reason a brand new Stage 2 clutch should be slipping under acceleration. Don't drive the car anymore until you figure out the problem, or you'll end up having to buy a new clutch and flywheel again. I'm not all that familiar with spec clutches, did the instructions say that the shim is required??

**JER-SS** · 07-21-2008, 09:37 AM

"It is not normal for the clutch to slip at all when it is fully engaged. That will cook the cltch disc lining and possible warp the flywheel and cause clutch chatter.

Did you make sure the flywheel was 100% clean when you put it in?? They generally ship with a coating of oil on them so that they don't rust, so you need to clean it with brake cleaner to get rid of any residue.

Sounds like the shim might be preventing the clutch from fully engaging, there no reason a brand new Stage 2 clutch should be slipping under acceleration. Don't drive the car anymore until you figure out the problem, or you'll end up having to buy a new clutch and flywheel again. I'm not all that familiar with spec clutches, did the instructions say that the shim is required?? "
Today 10:29 AM

Wesman,
I cleaned everything with brake cleaner before installing. The instructions i believe said to use it, but it sure seems like it would have the effect of someone riding the clutch, which is what is happening now. I guess it would only take a couple hours to pull the tranny yank out the shim and put it back together. Dang i sure hate to have to pull it again though ha ha ha.

You know now that i think of it im not too sure i cleaned the pressure plate though... I assume it would have had an oil on it as well for shipping purposes. Had a lot going on this weekend wife and kids were driving me nuts ha ha. the oil will eventually burn off though, right?

**Mr. Luos** · 07-21-2008, 10:14 AM

Stock flywheel?
Did you have it resurfaced?? If so, how much did they take off?

**JER-SS** · 07-21-2008, 10:18 AM

Originally Posted by Mr. Luos

Stock flywheel?
Did you have it resurfaced?? If so, how much did they take off?

stock flywheel did not resurface as I was told it couldn't be done on those flywheels. Flywheel was in pretty good shape though.

**Mr. Luos** · 07-21-2008, 10:23 AM

How did you bleed the system?
What fluid?

**JER-SS** · 07-21-2008, 10:27 AM

Originally Posted by Mr. Luos

How did you bleed the system?
What fluid?

I was going to bleed the system, but i never spilled a drop during the install just slid the slave cylinder off and on the input shaft during install and removal.

Never had to crack the lines allowing air into system.

**Mr. Luos** · 07-21-2008, 10:34 AM

First thing I would try in that case is bleeding it with fresh fluid. Even a small bit of air dicks the whole system up pretty good.

New slave cylinder wouldn't hurt either.

**JER-SS** · 07-21-2008, 10:39 AM

Ok I'll give that a try. Thanks! Nice looking TA by the way. I love BLACK!!

**Mr. Luos** · 07-21-2008, 10:47 AM

Thanks!
Good luck with yours.

It took me about 5K miles to kill a SPEC 5, but that was my own fault. It started slipping while in gear. I overheated it.
Had the stock flywheel (first mistake) taken down, but the machine shop took too much off. It grabbed for those 5K miles, but it would overheat. Chewed that material down to nothing pretty quickly.
Went to a SPEC 4 with new SPEC billet steel flywheel. No problems since.

You can machine the stock flywheel...but not much can be removed. .020" at most I think.

If you pull everything down, at least hit the flywheel with an emory cloth to give the clutch a slightly roughed up surface to grab too.

Does your clutch slip when changing gears? Or just once in gear?
Shifts are made fairly easy?
It kinda sounds like engagement...which can be related to air in the system. Anytime I have that line disconnected...I bleed it. Just in case.
Easiest way to jack up the T56 is to have the clutch hydraulics off a bit.

**JER-SS** · 07-21-2008, 11:17 AM

Originally Posted by Mr. Luos

Thanks!
Good luck with yours.

It took me about 5K miles to kill a SPEC 5, but that was my own fault. It started slipping while in gear. I overheated it.
Had the stock flywheel (first mistake) taken down, but the machine shop took too much off. It grabbed for those 5K miles, but it would overheat. Chewed that material down to nothing pretty quickly.
Went to a SPEC 4 with new SPEC billet steel flywheel. No problems since.

You can machine the stock flywheel...but not much can be removed. .020" at most I think.

If you pull everything down, at least hit the flywheel with an emory cloth to give the clutch a slightly roughed up surface to grab too.

Does your clutch slip when changing gears? Or just once in gear?
Shifts are made fairly easy?
It kinda sounds like engagement...which can be related to air in the system. Anytime I have that line disconnected...I bleed it. Just in case.
Easiest way to jack up the T56 is to have the clutch hydraulics off a bit.

Changing gears does great slips once in gear if you accelerate a little aggresive. Shifts are as easy as ever. One of the better T56's I've driven. The clutch pedal is engaging a little higher than it used to be... thats what made me think it might be the shim. I'll give bleeding it a try but i never actually disconnected a line, I left it all connected and slid the tranny away from it after unbolting the slave cylinder. I'll try anything though, I'm far from knowing everything ha ha ha.

**ws6race** · 07-24-2008, 06:30 PM

i got the spec 2 in my car also ... i didnt do the work had someone i trusted do it and i was getting the same thing ... would slip under hard acceleration thought that it might not be total disengaged so i purchesed the mcleod adjustable master cylinder... once again had the same friend work on it and bleed the system .. it seemed to work a better but not perfect .. so later down the road i decided to bleed it mysef after noticing that my clutch fluid looked like someone broke a pen and let the ink leak into the fluid .....

i bleed it this way ... disconnected the QD under the car had my girl pour fresh fluid into the res. as i used a small punch to open the QD valve and i just let a lot of fluid run through it like 1/2 a container ... than i reconnected it and had my girl go into the car ... and press on the clutch as i used this method http://performanceworks1.com/ls1_clutch_bleeding.htm it worked great .. the only prob was u have to do it a few times till the clutch feels firm again ...

but after doing both the clutch works real good now ... not sure if it helps but i would look into the second part first since its cheaper ..