I recall discussing this in another thread. I have already replaced the sliders with the new design rollers on my driver's rear window. The front passenger window, when it passes the halfway point, will clunk and appear to shift. I had assumed one of the sliders was broken. The door panel itself was due for a retainer fix (replacing the clips and gluing back on two of the standoffs that holds the retainers on the bottom) plus I needed to replace the courtesy lamp that I broke several months ago.

With the door panel off, I moved the window up and down. The sliders were not broken, but I couldn't tell what was wrong. The track itself appeared to have been messed with, and these were perhaps replacement sliders. I sprayed a liberal amount of white lithium into the track and that made a little difference but it was still definitely getting hung up. I also noticed that when it was halfway down, it would actually rattle/bang inside the frame. That was the tip I needed. Inside the door, there's a track in the front and rear that locates the window. On the front, the black felt had actually slid halfway down the metal frame. I have no idea how this happened. Perhaps the car sat for a while and someone went to roll the window down and it just stuck to the window and pulled it down. Not sure. As the window went down, it would clunk/shift as it entered the black felt guide. It was a bit of effort to pull the felt stuff back up but I did and the window works great now. Didn't replace the sliders because they seemed fine. With the extra lube, maybe they'll last a while.

So just one more improvement, and the panel is tight again with the new clips and glued holders on the bottom. Plus a working courtesy lamp. The rear pass door panel is very poorly attached, so I will do that one next. The other door panels all have brand new clips. And all of the other window sliders also work fine, so that's good. No pics, just a general update...