took the door panel off today to R&R the window motor, and this little black piece was sitting in the bottom. I was having window problems before the motor went out (i could move it back and forth about 1.5 inches among other things). is this the source of my problems? if so, what is it and how do I put it back in? Thanks!

 

I think that is a trim piece that goes on the window slides.
Keeps the window from going in or out ????

 

any idea how I can get in back where its supposed to be? That was the problem I was having....When rolling the window up, about 3/4 of the way up, the window would just fall inward..

 

That is a stop bumper that sits on the bottom inside the door. The glass rests on that in the down position.

Look at the window adjustment help on my Tech Page. You might need to adjust the stabilizers that are on top of the door.