Along the way I got a question about the little screws the factory put in vent windows and whether to reuse them. It's one of those "What the h*ll does this thing do?" questions...

The tiny screw is probably a set screw designed to inhibit vent window frame movement.

For decades I removed, but did not replace them since I couldn't figure out what they did. With or without these screws, the windows work fine.

When I was reassembling my passenger door yesterday, I decided to put it back in after watching the vent window frame move & up down, just a bit, with the spring-loaded force of the main window being wound up to full-up position. The rear edge of the vent window frame is a U channel that the main windows roll up into.

If I have it right, it's GM's form of a set screw designed to lock the vent window frame in place _after_ all adjustments are complete. My factory hole in the vent window steel frame was too far forward to work with my windows. That's why I never replaced it all along the way.

This time I just drilled a small 7/64" hole right where it needed to be.

So the process is to remove the screw, align your windows and replace the screw where it needs to be to secure the vent window to the door frame.

Hope that helps.
Chris

 

I have a similar screw in my 1964 Dynamic. I'm in the habit of putting the screws and bolts back in the hole when I take things apart so I always know which screw came out of what hole. Otherwise "bag and tag", but when I can, I put them back in the hole from whence they came for safe keeping, until I re-assemble. I was struggling to get my vent window back in- really struggling! I could not get the damned thing where I wanted and then I remembered that screw! It was in the hole where it belonged! I had to pull the vent window back out, remove the screw, and do it again.

So to answer question, "What does it do?"- If you forget it's in there, it really gets in the way!