LS7 Clutch Issues - Not the usual.
Thread Starter
Drifting
Joined: Dec 1999
Posts: 1,541
Likes: 2
From: Raleigh NC
LS7 Clutch Issues - Not the usual.
Background: A few months back I installed a new LS7 clutch setup with my new motor. When I went to tighten the harmonic balancer bolt the clutch would not initially hold. Not knowing what else to do, I bled the clutch. The clutch then held. Doesn’t really make sense to me but it worked. Once I got it all together the clutch worked great. It held the power of my 416. I was having some oil pressure issues due to bearing clearances so I decided to pull the motor. The clutch would not hold when I tried to back the balancer bolt out. Luckily my impact gun was able to back it out. I had an oil pan leak that did allow some oil inside the bell housing but it doesn’t look like it ever actually touched the disk. The bell housing had a damp oil ring all the way around. The car showed no signs of slipping while driving.
How much oil does it take to ruin a clutch disk?
Do I need to buy a new disk which also means a new pressure plate? There is no more than 850 miles on it.
How much oil does it take to ruin a clutch disk?
Do I need to buy a new disk which also means a new pressure plate? There is no more than 850 miles on it.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Are you sure it was slipping? That isn't much torque to hold if not slipping while driving its hard to believe it would slip when fully disengaged unless it wasn't releasing all the way.
Thread Starter
Drifting
Joined: Dec 1999
Posts: 1,541
Likes: 2
From: Raleigh NC
I had the car in 5th gear and the motor was rotating. You could see the tires try to move. The more I did it the easier it was to rotate.
FWIW: I did not adjust the pressure plate prior to install. I left it as shipped. The clutch held WOT 5th gear at about 140 at the track. After that 1 track session is when I discovered the oil leak. I only ran the one session because of the lack of sufficient oil pressure.
FWIW: I did not adjust the pressure plate prior to install. I left it as shipped. The clutch held WOT 5th gear at about 140 at the track. After that 1 track session is when I discovered the oil leak. I only ran the one session because of the lack of sufficient oil pressure.
Pro
Joined: Mar 2004
Posts: 653
Likes: 0
I've seen this before during a clutch change, where the old slave cylinder was re-used. The old slave had a full charge of fluid, and was extended to the limit of the old clutch resting position...evidently further out than the new clutch.
In our case we observed that the torque tube just wouldn't push up flat to the bellhousing, and we didn't want to use the TT bolts to pull it into place. I cracked the bleeder open, my helper gave a push, and it seated into place easily while a small amount of hydraulic fluid squirted out. No further issues.
As far as your oil issue, very likely it's on the clutch plate. The ring of oil splattered around your bellhousing interior is a dead giveaway...it got centrifuged there by the flywheel & clutch assembly. Doesn't take much to start a clutch slipping.
