The Regulator Frame that is made of something like the Metal Carburetors are made from bends.
The Gear teeth on the Motor are extremely Hard and begin to eat up the Regulator Gear Teeth that are soft compared to the Motor Gear.
Also at the time I posted the below thread a rear Window Regulator was about $150 something. Since than the price has go up a lot.
I replace one because I believed the Teeth were too bad on it. I suppose the Teeth could have been welded and ground or filed back into shape but that was too much work for me.
Extreme Window Regulator Repair
http://www.peachparts.com/shopforum/showthread.php?t=254722&highlight=Extreme