Excellent observation. I don't believe I had that issue when I took it apart to examine it but when I put it together I did not have the glass aligned and it was out of the rack on the front. I found it and corrected it, but it was still dragging pretty bad. I did notice that if I took out the horizontal door seals it runs up and down pretty well. I may try to replace them and see if that helps. But as they get old, why would the drag so much and why the passenger side that likely has seen less use?
T2000 Complete (but never finished)