996 Clutch with measurements, when it is due to change?

[Domiac]

Car is 996 Carrera, 2004, 3.6L, 85t miles.

Please have a look at the picture. I suspect that the clutch has been changed at least once on this car. Measurements for the discs are 2.98mm and 2.89mm. Marks on disc 1 are clearly visible, on disc 2 some of them are not perfect anymore.

Would anyone happen to know what width the original discs have and what is the minimum width before change is required? It would be nice to know how long due is this clutch before I reinstall my tranny and engine back to my car.

This clutch disc is identified as 997-116-013-13.

Good quality images here: https://www.dropbox.com/sh/6v7k6w2trilayhd/yzH4BkI4BU

Thank you!

[JFP in PA]

A lot of factors come into play on when to replace the clutch assembly. As most people do not know to compress the marcel spring between the clutch disc faces before attempting to measure the disc thickness for wear the way you were doing it in the photos, and little information is published on disc wear limits (but I will see if I can find something), disc face measurements can often be misleading. And, as strange as this may sound, we look at the pressure plate fingers and throw out bearing for signs of wear. Quite often, the fingers and/or the bearing show a lot of wear before the disc even begins to look poorly. And If you are going to replace the pressure plate because of finger wear, it makes no sense to reuse the worn disc.

At the end of the day, a clutch kit does not cost that much, assuming the flywheel is still in good shape, and when doing an IMS you have already spend the time to get in there, so it makes sense (particularly financially if you are paying someone to do it) to reuse the clutch. Once the car is buttoned up, you really don't want to go back in to swap parts you could have replaced while it was apart.

OK, I found some factory data on the disc face wear:

But I would still look at the pressure plate fingers for wear, regardless of how the disc measures.