1982 door window
The door glass goes up and down on nylon rollers. With time, the rollers wear and get sloppy. There are 5 rollers per door glass. Three are riveted to the regulator, one has a square block that it slides on in a track that bolts to the glass, and the final one is bolted through the front of the glass itself. There is a rebuild kit available that includes the 2 rollers for the glass and all of the door glass bushings. The kit sells for about $46.00, and does one door. The riveted rollers for the regulator are also available, and cost about $20.00 each.
The other thing that effects the movement of the glass in the doors, is the anti-rattle cushions. The cushions are at the top of the door, on the outside of the glass. They can be adjusted to put presure on the glass, to prevent it from moving around in the door. These cushions have a "fuzzy" surface and a foam backing. With age and use, the fuzz wears off and the foam dries out. Each door has 2 of these cushions. They sell for about $30.00 a set.
Below are illustrations from the Corvette Parts Book, of the door and glass hardware.
Number 3 in this illustration is the roller that slides in the track, and number 9 is the one that bolts to the glass.

Numbers 1 and 11 are the same two rollers seen in the above illustration. Number 32 is the anti-rattle cushion. Unfortunetely, this illustration doesn't show them or their location, well. The 3 rollers attached to the regulator, were never serviced separately by Chevrolet, so there is no illustration of them. The regulator is #79, and the rollers are part of it. Luckily, the Corvette aftermarket does offer these rollers, without having to buy an entire regulator.










