[moku]

Could be a motor issue or something in the track causing the roof to stick in certain places.

Probably best to start with the easier, less expensive options and try checking the track and ribs of the roof to make sure there's nothing causing it to stick or jerk. Then you can think about changing out the motor. And as a last resort, you can replace the entire unit.

I had my motor die out on me, and because my top was scratched up a bit and a few of the ribs were broken, I replaced the whole thing. Things are much better now, but it did cost nearly $2000 when it was all done.