Through thick and thin

I saw a post today on F-Chat that was kind of interesting. Someone was asking about whether they should reuse the clutch on their 328, and they wanted to know if a 9mm thick friction disc was acceptable. For a 328, 9mm is within the wear limit and is probably fine.

This got me wondering, so I looked up the spec in the 308GT4 workshop manual for an early 308 clutch. This is what I found:

Thickness of driven plate without load: 9,2 - 9,5 mm
Thickness of driven plate under load: 8,5 mm
Wear limit of driven plate: 1 mm

I read this as the new plate should be between 9.2-9.5mm and the disc is considered worn and "out of spec" if it's less than 8.2mm thick. My new friction disc is about 9mm thick (depending on where it's measured). The fried one I pulled out was 6mm thick. A difference of 3mm, or 3 times the wear limit. Hmmm...I think my clutch is worn out.