Just today, I noticed that my driver's side window "clanks" on it's travel about halfway between up and down. At the same time as it clanks, it moves (shifts) slightly askew as if it's going off it's track. It successfully completes the full up& down, but I didn't want to exercise it any more than I needed to going through the toll booths (yes, I forgot my ezpass). Anybody have a suggestion as to what the problem might be, before I either take it to the shop or attempt to tackle the problem myself?

Thanks!

Dave