Chris -
That might be a difficult gear to mold. I looked at the picture you posted, and it looks like a stepped gear. Meaning it has two different gears on it, a smaller one for input and a bigger one for driving.
BigWalton, it plastic because it is cheaper, and quieter than metal. I am pretty sure that most moonroofs use a similar set up.
The problem could be that the teeth aren't getting full engagement. I think that is what Chris was trying to fix in the beginning.
Chris, are the teeth on the plastic gear stripping out/mashed down? If so, it could be a number of things. If the teeth aren't harmed and the worm gear on the motor isn't engaging them, then you could have an alignment problem.
Later,
Patrick
