Clutch Disc Thickness 6MT (in MM) question.

[Bmw M3 Guy]

As everyone knows, I'm having a new engine installed from BMW. The mechanic working on my car is doing a whole complete check up and analysis. The clutch being one of them, he measured it to be .90 mm for the actual clutch disc. His computer is saying to only replace the clutch when it hits .40 MM.

I wanted to find my own research of what a new stock clutch is in MM.

Does anyone know off hand?

Thanks,

Justin

[jphughan]

You might have some success contacting enthusiast vendors who deal with OEM parts, like maybe Turner Motorsport?

Incidentally, how many miles are on your current clutch? If information about the original thickness surfaces, it would be nice to have a data point to get a sense of the wear rate. I understand clutch wear is highly driver-dependent, but one data point is better than none.

[kenwelch]

Originally Posted by Bmw M3 Guy

The clutch being one of them, he measured it to be .90 mm for the actual clutch disc. His computer is saying to only replace the clutch when it hits .40 MM.

I wanted to find my own research of what a new stock clutch is in MM.

Does anyone know off hand?

Thanks,

Justin

2009 BMW M3 4.0L Eng
CLUTCH - TECHNICAL DATA
CLUTCH WITH DRIVE PLATE MECH-SPECIFICATIONS

Lateral run-out deviation of diaphragm springs to pressure plate mm 0.6

Minimum lining thickness of clutch disk:
Lining surface up to rivet closing head mm 1.0
(like "B" in the diagram)

This is from Mitchell Pro Demand information system.

To get the new measurement you will need to visit the dealer parts department with the digital caliper measurement tool. From my experience I would install a new disc now while the transmission is out. It will save the labor cost of doing the disc change next month. Your disc friction material thickness is already under the specification I located.

Check the run-out of the old disc also, the specification is provided.