Bagso

Had my 997 a few years now & had to replace the clutch at only 18k, as a second hand car i suspect the previous owner gave it a pretty good spanking out the box. Now 10k miles later I have had an independent change out my fixed drive as the slightly noisy gearbox became worryingly more noisy - turns out a couple of teeth were chipped. Further evidence of some initial abuse.
The gearbox is great & quiet now but the clutch which was replaced 10k ago now exhibits some strange behaviour. Working it hard through the gears it seems ok and same as before the work, but particularly when accelerating from a steady speed in 4/5 and even 6th around 3-4k rpm it shows signs of intermittent slipping.

Odd that it can handle the full beans & then chooses to slip under a steady load, could the work have upset the hydraulics in some way?
Any suggestions what could be going on here?

mattyf

Slippage in high gears makes sense to me, but let me think the best way to explain it. The engine produces the same torque, but in high gears it's harder to accelerate the car. So you push the pedal down more and get slip. So it's probably slipping in lower gears too, but it's harder to notice unless you push the pedal hard.

Edgy01

When you say "the clutch" was replaced. What exactly was replaced? Throw out bearing? Pressure plate(s)? Clutch disc?

Macster

A properly working clutch should not slip in any gear.

If the symptom appeared *after* the final drive was worked on I have to believe the clutch's behavior is related.

I assume the clutch system has been properly flushed and bled? Recently?

Unlikely the above could account for the symptom, though.

My WAG is an engine or transmission/final drive mount is loose, or not installed properly, something like this, and the engine/drivetrain is twisting and this is causing the behavior you report.

A less possible explanation is the clutch's friction surfaces have been contiminated with some fluid (oil?) and the clutch is slipping due to this. But I would think there would some sign of a fluid leak. However, you would have to have the car in the air and its underside inspected very carefully for any signs of a leak.

I'd take the car back to the shop that did the final drive work and have the engine/transmission/final drive mounts and in fact all of the clutch hydraulics/linkage checked out.

'course, you are relying upon a shop that might have screwed the pooch to recognize this and make things right.

Sincerely,

Macster.

Bagso

Thanks for the comments.
Just the clutch plate was replaced before, the pedal does seem a bit higher now since the work.
I have not had the system flushed so maybe this is a quick option?
It's not severe, just irritating & can't be doing things much good.
If I get the chance between all the hail, snow & sleet here I will give it a good run to see if it's just residual paw contamination. Any thoughts on how long you would allow to eliminate this aspect?
Failing this I will go with the full final drive check.
Thanks

997_rich

I don't think flushing/bleeding will help. This will help you DISengage the clutch better. If you had trouble disengaging i'd recommend that route. You have trouble with the clutch staying engaged. This means goop on the friction or pressure plate, poorly assembled clutch assembly, broken or lazy spring, sticky spline (misaligned by poor assembly of trans assembly?).

I'd expect most residual goop on the friction or pressure plate would be burnt off in 5-10 slippages but it depends on how much is there. If it doens't get burnt off in 5-10 slippages there is probably A LOT of goop (oil,grease, etc) on those surfaces- too much for a technician to ignore.

Good luck!