The Captain

My driver's side power window moves from front to back when it is rolled down. I took the door panel off and found that there is a roller attached to the bottom of the window. That roller has broken off the window (attached at the bottom of the window to a metal piece that is rivited to the window). Any way I can fix this? I tried JB welding the roller back on, but it broke off again. I'd take pics, but that would require taking my door panel back off.

Z28SORR

The white nylon roller is just pushed onto the "metal piece that is rivited to the window". This piece should end in a ball. You can not glue the roller onto the ball as it needs to roll and pivet on the ball. It take a lot of force to push the nylon roller onto the ball if it goes on "to" easy it will just pop off again. You can get new nylon rollers at the auto parts store, often in the HELP Parts Sect.
But you haven't asked why it came off in the first place. In most cases one or more of the window channels are loose. Check all the channels for loose or missing nuts and bolts. Some times the greese gets old and dries, which causes abnormal loads on the Regulator Arms and rollers. These arms can become bent and add more loads to the roller. As this is a window roller, and not one of the arm rollers, this is probably NOT the problem. Another cause can be an out of adjustment window. If the channel are not adjusted properly they can place abnormal loads on the window rollers. Because of the age of this car I don't think this is the problem either, unless you've had work done resently.
I would replace the roller with a new one by removing the window from the door. This allows you a chance to check to see if the channels are loose, then clean and regreese them. I know this is kind of a pain, because you have to remove the regulator/motor assem., upper window stops and window "anit-rattle" brackets but it's the only way.
ShoeBox has some good picts. on his web site.
These guys have lot of illustrations: http://www.gmpartsdirect.com/

The Captain

Here is the diagram:


The part that is broken is the "roller" that goes into the channel numbered 16. It attaches to the window. I am thinking its number 4 on this diagram that I need to buy, but am not sure. Any ideas?

Z28SORR

Doesn't look to me like they are showing the roller on that diagram. Part 4 are the "Retainer Backs". Any parts department should be familiar with these rollers.