996 Clutch slip

Hi Guys, I slipped the clutch really badly when coming off the lights tonight, after some really hard driving. The smell of burning was pretty horrendous. As a result the clutch 'bite' feels softer, spongier. Can anyone tell me if I might have done permanent damage (ie clutch plates need replacing) or whether the clutches feel softer when they are hot? The accelerator also feels lighter / accelerator cable maybe looser due to now worn clutch..? The clutch has just been replaced before I bought it two months ago. All else in the car is running fine - engine temp, tick over and pressures. Any comments or advice would be much appreciated! Cheers, Henry

Just let the plates cool. Should be alright in a few hours. If anything you may have done them a service by deglazing them.

Thanks GT4..! Will the normal feel return to the clutch bite or will it (and the accelerator tension) still feel softer..? Oh, and 'scuse the ignorance but what is this glaze on them (and the clutch plate system) made of? :thumbs:

The "normal" feel will return, as long as: 1) The glazed version was not what you considered "normal" (if it was glazed) 2) The clutch didn't happen to be genuinely on its way out just when you did this. This is unlikely as the clutch is self-adjusting and would be on the floor (biting point) if it had gone. The glazing is just where the clutch plates have been worn (by gentle clutch slip) to a shiny, smooth surface (looks shiny and smooth like a glazed plate). A few aggressive clutch burns (or less gentle general use) removes this glossy surface, restores a roughened surface and gives back some bite.

That's really helpful GT4 thank you.. I will update when I have had a chance to check this.. :thumbs:

The "soft" clutch and (temporary) continuation of slippage is just because you (temporarily) overheated them. It is just like brake fade. If you brake too much and (temporarily) overheat your brakes (disc/pads) you lose the feel and you lose the braking efficiency. However, once cooled down again all is OK again.

I would probably have known this if I had done a track day. I love pushing the car and am not prone to slipping my clutch but I was burning a Beemer off the lights. Job Done - even if I did smell like burning rubber afterwards! This is all good to know - your experience is to my benefit..! Thanks GT4 Master! The support is great on 911UK.. :thumbs:

Truth be told, I did exactly the same about two weeks ago. Jeepers, did it stink! I used to have to regularly de-glaze a Golf GTI PD150 chipped to within a hairs-breadth of the clutch spec. It would need the 100% new friction surface to get any consistent clutch grip. However, over quite a short period of time, it would wear smoother (perhaps only a few percent), but then it was a viscious circle. As less friction lead to more slip, lead to more smoothing, lead to more slip etc etc. I would hold it fully on the handbrake and rev the engine, then slowly let out the clutch until it made a nice smell, then the clutch was back to new again.

Interesting tip.. do you think I will need to try this?

...or are you saying I just did this?..!

No, I wasn't advocating doing it. There are very specific reasons why you might. That Golf had the wrong spec clutch (ie original) for the non-original power (torque) upgrade. The point I was trying to make was that the accidental action you performed sometimes is done deliberately. Howerver, it is still not a great idea as it sacrifices a lot of clutch wear to get the glaze off. Ordinarily you would aim NOT to do this. But if you do it, it isn't the end of the world. Stop chasing BMWs!

996 clutch slip I wasn't chasing the BMW, he was chasing me. He started it! (But I wiped the smile off his face). I would not normally chase anything but a Porsche... As you correctly summise, the clutch is back to normal again. I hope I haven't worn it down too much.. how long do they last if you drive them every day? Clever stuff.. :thumb:

Re: 996 clutch slip How long is a piece of string? It depends so much on use, and user. Motorway miles or London miles have a very different affect on clutch wear. You can usually tell when it is on the way out as the pedal pressure increases quite a lot. They hang on for quite a while like that before slippage starts, so it is a useful indicator to get it seen to.

When I bought mine in November last year it had done 26K miles and the clutch was heavy, so I had a new one fitted. It is now on 35K and going beautifully. I dont expect to have to change it again, even if I do another 50K in it. I am glad I'm not the only one that gets a stinking clutch after a few fast starts!

As Richard says, how long is a piece of string? Obviously if you drove continuously on the motorway it could be 100k miles+ I would say during "normal" use you might consider 30 or 40k as a reasonable guestimate (this is probably still another +/- 10k miles for the first standard deviation of use though).