Clutch Break-In

[chris_seven]

We fitted a new lightweight flywheel/clutch package to a 3.2 Carrera last week.

We initially noticed that the 'bite' point of the clutch was quite high and that there was a slight vibration.

Over a few days the vibration became worse to the point we removed the engine to see what was happening.

There are clear 'high spots' on the flywheel which don't look too clever.

We have re-fitted the original flywheel and a Sachs Clutch and all is well.

The supplier tells me that we need to carefully 'break-in' the clutch for a minimum of 500 miles and that the 'hot spots' are at the point of contact with the clutch straps on the pressure plate.

It appears that these hot spots would not have occurred if we had bedded the clutch in correctly.

Having been fitting new 911 Strap clutches for a number of years I am surprised that there needs to be a specific break-in procedure other than a little but of common sense.

The car has also had a major engine re-build and is still being driven quite carefully.

Any thoughts?

[Lyle O]

FWIW, I installed a Centerforce Dual-friction clutch this spring, and in the intallation packet they recommend using the clutch in "stop and go" and street traffic for the first 450-500 miles, which I followed probably 65%. Clutch is smooth as silk, strong as a tank; I'm at 950 miles now. All is good.