Clutch Engagement / Disengagement Issue...TOB or PP?

[DKneble]

I am a little stumped on this problem and I would like to see if anyone else has had this issue before I start helping my friend tear his trans off.

Car has an ACT2900 clutch and ACT flywheel with less than 3k miles and is making about 500awhp (2g GSX) with no previous clutch problems. While doing a hard pull in 2nd, he tried shifting into 3rd but the clutch didn't fully disengage so he missed the gear. He re-pumped the clutch noticed it was very soft but he ended up getting the car into 5th and nursing it home.

Clutch does not fully disengage with the pedal depressed so getting into gear is hit or miss. Clutch also slips like crazy...tough time getting up the driveway in 1st gear...but drives fine at highway cruise speeds.

Checked the slave and master cylinders for any signs of leakage and pressed the pedal to verify slave rod movement. Everything looks good. Reservoir looks good too so no indications of fluid loss. There are no vibrations or strange sounds coming from the engine/trans when running at idle out of gear or when cruising.

Ideas? TOB would make a lot of noise if it was shattered correct? Could PP bolts have loosened? Is there a way a master cylinder could go bad where it wouldn't allow the clutch to fully engage all of a sudden?

Thanks in advance.

Dave

 

[cabbageman97]

I am a little stumped on this problem and I would like to see if anyone else has had this issue before I start helping my friend tear his trans off.

Car has an ACT2900 clutch and ACT flywheel with less than 3k miles and is making about 500awhp (2g GSX) with no previous clutch problems. While doing a hard pull in 2nd, he tried shifting into 3rd but the clutch didn't fully disengage so he missed the gear. He re-pumped the clutch noticed it was very soft but he ended up getting the car into 5th and nursing it home.

Clutch does not fully disengage with the pedal depressed so getting into gear is hit or miss. Clutch also slips like crazy...tough time getting up the driveway in 1st gear...but drives fine at highway cruise speeds.

Checked the slave and master cylinders for any signs of leakage and pressed the pedal to verify slave rod movement. Everything looks good. Reservoir looks good too so no indications of fluid loss. There are no vibrations or strange sounds coming from the engine/trans when running at idle out of gear or when cruising.

Ideas? TOB would make a lot of noise if it was shattered correct? Could PP bolts have loosened? Is there a way a master cylinder could go bad where it wouldn't allow the clutch to fully engage all of a sudden?

Thanks in advance.

Dave

Questions : 1- Yes, you would definitely know.
2- It's possible. What did you originally torque it to?
3- Over-fill it and it MIGHT. Not often but I have seen it happen. It should be about a 1/4" from the bottom of the cap.

My suggestion is to by-pass the "clutch fluid chamber". ACT actually recommends this once you upgrade to a stiffer clutch. It should be on the left of the transmission on the front side just before the slave cylinder. All it does is dampen feedback from the clutch. It should give you an extra little wiggle room. Try it. It can't hurt either way.

 

[DKneble]

I kinda figured I would definitely know listening to his car. The only time there is noise is from the clutch slipping as you let the pedal out...no noise out of gear with pedal up or down and no noise in gear with pedal depressed after you give it (2) pumps.

He has already bypassed the chamber and has a SS line on there.

Another friend of mine had his 2900 disc shear the pins holding on the pucks right off but I would think this would have horrible noise with it too.

A loose pressure plate would explain the slipping but not the lack of disengagement.

A blown out TOB would explain the lack of disengagement but not the slipping.

Right? This is why I'm stumped.

 

[saechao04]

I too am having issues with a slipping clutch. Maybe where you adjust the master cylinder rod got un-adjusted? I noticed the nut on mine was backed out half way after my clutch started slipping, I had no idea it was even loose as a shop had replaced my master cylinder.

 

[DKneble]

No signs of any movement of the adjustment nut on his car...was one of the first things I checked. I would have to check it again but I think the clutch felt fine with the car off and soft once it was running. This indicate anything?

Dave

 

[95blackGsTurbo]

What disc does it have in it Dave? I have seen a couple 2900's have an issue with the prssure plate fingers bending and not wanting to apply proper pressure while the pedal is released. This would explain that slipping that you are getting as well as not getting a ful disengagment. In any case if it is not a hydraulic problem, the transmission is going to have to come out. Only other thing that comes to mind, but you already probably checked, is the pedal adjusted itself out.

 

[DKneble]

Its a 6 puck unsprung disc. The pressure plate is what I have been leaning toward...either bent fingers or bolts backed their way out somehow. And yes already checked the pedal...unfortunately looks good

Out of curiousity how/why would the fingers bend? Just looking for some insight

Dave

 

[95blackGsTurbo]

The fingers just do sometimes. Not sure if there is an actual reason ACT has founf out why. There is always the chance the pressure plate is coming loose

 

[DKneble]

Wish there was some way to torque the pressure plate bolts without pulling the trans...sigh

Turns out there is a way to check torque on those bolts through the shift fork opening in the trans. Bad news is that they were all still tight. Closer inspection with the flashlight shows at least one 'finger' of the pressure plate is bent toward the flywheel...this explains everything!!!

Friend already called ACT and they said that they would replace it free of cost if it is a manufacturing defect, regardless of mileage.

I will let you all know how this turns out in the end.