After feeling all proud of myself for repairing my sunroof motor, I am now faced with a new problem of my own doing.

Correct me if I'm wrong, but the large gear (driven by the worm gear on the motor) is designed to turn feely on its shaft once the roof is fully opened or closed, or else the motor would wear a groove into the teeth of that gear. This appears to have happened in my case, presumably because I tightened the 17mm nut too tightly on the shaft on which the large gear rotates. There is a steel plate which contacts the smooth surface of the large gear, and friction from the locknut engages the gear until the roof stops, whereupon the gear can turn freely if the friction is not too great. It was too great in my case...

Does this sound right? Is there a cryptic torque spec for this nut, or is it trial and error?

Instead of haunting the salvage yards for another gear, I was able to rebuild it using the amazing versatility of JB-Weld and tooling the damaged teeth (about 30% of the total) to match the others. We'll see...

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Matt
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1995 E300 Diesel (Die Blau Frau)

This is supposed to work as a "clutch" , it should be able to slip under extreme pressure.
At dealer we set up the clutch by allowing the motor to draw approx 10AMP(max) when at full open position. AT that point the clutch will slip. This is done with 17mm jam nut & large screwdriver.

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