I am having the common problem where my driver's side door window is sticking when lowered all the way down. After further investigation the crescent shaped part of the regulator (attached pic - it is a rear regulator but the same idea) is coming out of the teeth on the motor assembly. All of the plastic wheels on the tracks are greased and OK.

As the motor is designed to stop once it meets resistance, how does it usually stop on the downward motion before the crescent comes out of the motor? There is a small hole in this part that I tried to put a bolt through to stop the down motion, however it sheared off (yes, apparently the motor is that powerful, not sure if it meant to crush cans/monkeys/giraffes etc.)

RAVE has no ideas, and I am loathe to pull the membrane off the passenger side to see what is going on there...

2002 Discovery 106k

 

I replaced my regulator on my 99 Disco recently and there was a plastic extension that was bolted to the track the window sets into. This plastic piece protruded about 2" lower than the window and stopped the downward motion by coming to rest against the bottom of the door.

 

Brief update, I ended up fixing the window by attaching a length of steel running horizontally along the interior of the door frame, which stops the window from lowering too far down. Not the most elegant, but it is stopping it coming off the regulator.

 

a good rule i use is to never lower the windows all the way till they bottom out.

 

Mine was doing that too. The welds on the regulator are not very good. One of the (three I think) welds was broken so the crescent shaped gear was loose enough to allow it to ride off of the motor gear at the bottom. I didn't see that until I pulled it out of the door. I welded it up and it works fine now though.