My driver's window only go up 1/4 of the way. Then it gets stuck and make very loud sounds like a gun machine.

Where should I start to take care of this problem ? Thanks.

I can't believe the winder is that strong. The ratacha sound is loud and startles me everytime I forget and push the up button. Anyway, it goes down very smooth, but it goes up only 1/4 of the way.

Thanks for your help.

1992 W140 300SD Diesel Turbo, 3.5L .