AEsco48

Is there a way of checking the remaining clutch material thickness without separating the engine from the trans?
If it makes a difference the engine/trans are out of the car.

997gt3north

My 2 cents is if you are in there and have a high mileage car, especially track miles, and there are going to be more track miles, then install a new pressure plate and friction disk.

GT3s don't generate that much tq so the friction disks never really go - what happens with track miles is the pressure plate starts to fatigue and that is eventually what lets go - totally different if you have turbo tq or you are drag racing.

If it is a street driven car and has less than 35k miles then leave it.

If you see lots of material transferred from the face of the friction disk onto the pressure plate then you know you have been driving hard and likely the pressure plate is 'aging'.

AEsco48

Thx for the info. Is there a procedure to quantitatively measure?

NBTBRV8

I had to do my clutch, pressure plate and flywheel at 50,000kms. Do a search on Clutch wear symptoms on here.

997gt3north

here is a link to a picture of a pressure plate where you can see the transferring of friction material from the friction disk to the pressure plate

http://i283.photobucket.com/albums/k..._1456Large.jpg


There is nothing about the transferring of the actual material in this picture that makes it 'bad' or 'unusual' - it is just what happens. This pressure plate is from an RS4 according to the picture. An RS4 pressure plate is a common 'upgrade' for Twin Turbo S4 cars that install bigger turbos as it has 'around' 50% higher clamping force than the S4 pressure plate. Interesting is that the friction disk for both the S4 and RS4 are the same and they look nearly identical to those used in GT3s. The 'burning' / 'melting' of the friction material onto the face of the Pressure Plate, in this picture, is typical of turbo cars that have 500tq (i.e. 70% more than GT3s) - it comes from dropping the clutch for red-light races. You can also get this on a GT3 if you drop the clutch at a red-light but I would highly, highly discourage this as the massive weight over the rear tires leads to the chance of destroying other expensive things back there.

Anyways, even in the picture of the 'melted' friction disk material on the pressure plate above, we really have no idea if the pressure plate is good or bad as what generally matters for GT3s is that the Pressure Plate fatigues - it isn't really the face of the Friction Disk or Pressure Plate (unless we are at 200k miles) that is going to say 'change me' unless you live at the drag strip and then you will see that 'melted' look on the friction disk as well.

From experience around here and with lots of turbo cars, GT3s generally change the pressure plates and friction disks when:
- Porsche sells a ****ty product like they did for the 3.8RSs
- you money shift and the Pressure Plate explodes to save the engine
- you service the car after 5-7 years, the car has 50k miles, you have done 40 track days, you decide that you are already in there and may as well pay up now to save on the labor while the engine / tranny are out welding the coolant lines

AEsco48

Per dealer measurements she is at 50% pad material remaining. Car has 50K miles.

Thoughts?

TYPE911

Since you are already there, I would go ahead and re-new. 50K on a clutch in these cars seems pretty good, or is that average life?

AEsco48

Renew =$800 on a new disk, clutch and bearing?

TYPE911

Closer to $1400. My clutch was replaced @ 22,600 by previous owner due to flywheel issue at dealer. Pricing may vary, but here is what was on the invoice.

Disk $455
Pressure plate $715
T/O bearing $227

997gt3north

I would replace the friction disk for sure - 100%.

The important decision is the pressure plate
- if you track, and you are going to continue to track then yes (i.e. 6-8 days per year for next few years)
- the reason here is that 6000rpm repeated heal/toe downshifts stresses the metal fingers in the pressure plate - it is cumulative - the metal fatigues and one of these times it will break / stop working properly
- if you are away at a track weekend and it happens then you really blow your weekend and that sucks
- if street driving weekend car then no

Spyerx

I'd replace disk, PP, TOB, guide tube, and the little bits on the fork, etc. Inspect flywheel and if OK skip it. You're already in there.

My Original clutch had 36k miles and was in decent shape, but the action was getting a little notchy and would on rare occasion shudder in reverse (only a few times). Its perfect now. I went with full 4.0 setup including new flywheel.

Have them inspect rear main seal too. Replace if seeping.

997gt3north

ditto on the rear main seal

also, if the engine is out, there are a few coolant lines i would replace for sure + spark plugs + a few other things

997gt3north

and, if this is a 50k track car, and it is the OE LSD, have your shop take a look at it

AEsco48

In the future if the clutch has issues you can drop just the trans and keep the engine in, right?

Tom@TPC Racing

+1 on new clutch. I changed mine when I first bought the car at 46K. The clutch pedal feel was not good and even with the pedal pushed all the way in it was hard to shift; it was as if the pedal with only pushed half way. I thought I was going need a trans rebuilt but the new clutch made it so much better.