I tried to swap out my passenger window regulator this afternoon. The old one had a busted plastic wheel. I have another that was pulled from another Disco which appears to be in good shape. The motor works fine and the teeth look good. The swap was pretty straight forward except...when I try to roll the window up it gets hung up and I hear the gear teeth slipping and grinding. There seems to be some play as I can rock the window side to side a bit and it seems to be coming up at an slight angle. I can help it roll up by pulling on the window while pressing the up button. Once I get it to the top if I hit the up switch it still grinds gears instead of the motor stopping.

Did I not install it correctly? It rolls down very smoothly no problem. I have tried greasing all the tracks on the new regulator which did not help. The motor is mounted correctly and is tight.

 

After sleeping on it last night I tried a few more things this morning, I taped the window all the way up and removed the screws so that only the regulator will go up and down and it still grinds without the weight of the window. Trying to repair the roller on the original regulator and see if that one works. The window never grinded before, it would just get stuck on the way up since the roller was broken and jammed in the slide.

 

Nope, old regulator does the same thing...maybe the motor is bad too...

 

Ended up being the motor, new to me one installed and everything is good. Hope this helps someone when troubleshooting their window issue.