[johncc]

I replaced my manual box with a recon item about 10,000 miles ago, and at the same time replaced my clutch, using a Saab clutch kit, as well as the slave cylinder and thrust bearing. I didn't resurface the flywheel as the car only had about 90,000 miles on it. When I fitted the clutch I cleaned the flywheel and the friction surface of the new clutch.

I'm currently trying to set up an MBC, which is another story, but as a result I'm getting some fairly wild boost levels momentarily (~18psi) and I am finding that in 2nd or 3rd gear, as the boost peaks, the clutch slips for a second or so. It doesn't seem to do it in 4th or 5th.

Assuming the clutch kit was OK, then what could cause this? My worst fear obviously is contamination, and none of the options are appealing. It would mean either a leaking slave, a leaking crank oil seal, or a leaking seal on the new box.

Short of dropping the box out again, can anything think of anythink else that could cause this (e.g. hydraulic problems, although I can't see how), or any way I can check what's going on?

The last thing I want to do is have the box out again so soon

 

[djtaylor]

Weak pressure plate? You didn't state what came in the kit you had.

 

[johncc]

It was a three part kit. Pressure plate, clutch disc and bearing, as purchased from a dealer. I also did the slave cylinder.

 

[djtaylor]

So one can assume it's not the pressure plate then. Don't know what to suggest, hopefully someone else can shed light?

 

[Superaero]

My 97 Aero started doing this after I switched to platinum plugs. New clutch kit dealer installed, and it slips at peak boost in fourth or fifth gear. My Boost Guage is going off the end of the red and the car runs like a scalded leopard. The clutch slips momentarily then grips again. After a few of these little heating episodes the clutch grips like iron until the drivetrain cools off again. Only really notice this at highway speeds.18 psi is too much boost, even the Aero is only 1.02 bar max boost. I'm surprised your overboost fuel cut off isn't going off all the time. My 97 Aero cuts off the fuel fairly often, say about once every three months or so, seems to depend on how cold it is outside and how fresh the fuel is...