I'd been living with the seemingly common problom of my vanagon's door 
lower slider scraping the front part of the track just where it makes 
the turn into the body. Over the years the weight of the door must have 
straightend the angle braket that connects the slider with the door and 
allowed the slider to just barely scrape on the body and wear away the 
paint. adjusting the angle bracket has no effect on this (just moves the 
door up, down, in, out). 

So the quick fix was to remove the slider from the bracket (you'll have 
to support the front of the door on some blocks), clean it up, and 
reattache but with the washer on the inboard bolt (the one closest to the 
centreline of the van) betwwen the slider and the bracket. This angles 
the slider enough to allow stop that scraping. Some light sanding and 
paint on the scraped track and it looks great.

alistair