Mmmmm. The only time I've seen anything similar was on a 24-120VR that I dropped (don't ask). I doubt there's a similarity in mechanisms, but here goes just in case. On the 24-120 beneath the rubber ring there's a slot in the ring, within which a wedge or plate is installed to engage a helical spiral in the lens barrel. Turn the ring and a nubbin on the bottom of the plate engages the spiral slot in the lens barrel to extend or retract it, changing focal length in the process. Since the 80-200 doesn't stretch with f/l changes, something different must be at play in there.
The only reason I bring it up, the result of my drop was to pop the screw loose holding that wedge or plate. Not only was the screw free and gumming up the works, it's loss allowed the wedge or plate to move too much and wedge the helical rather than slide along it. The threads in the plastic wedge were stripped, but I needed the lens ASAP rather than shipping and waiting. I put a tiny dab of 5-minute epoxy on the screw and put it back in place. Half an hour later I started using the lens again, and it's never given me trouble since.
Whether or not there's anything useful to you in that account, I'll still claim credit for quick thinking under fire and telling a pretty fair story years later !