Looking at the inside of the clamp where it grips the glidebar, I noticed there were 4 polished rectangular sections which causes the clamps to ride the glidebar smoothly.
On the troublesome clamp, 2 of the polished sections have been eaten through significantly and now have the rougher texture of the clamp. My dad suggested using a drill to re-polish the rougher sections while being careful not to take too much off.
Is this the right course of action?
ps: I waited too long to take pictures and the sun went down. The pictures I took were unusable. I'll try get up decent pics soon