Need help! My 1977 TC power windows work, but when the WING window gets down to the point the full window begins moving down there is a loud noise like something catches. It does this on BOTH SIDES of the car's front windows. Finally, last week the WING window glass came apart from the frame that guides it. Luckily NO glass broke. I took it to a body shop, they pulled the door panel and put the glass back in the track guide with adhesive and a week later it came apart again! Also, when the door panel was off, there was a GREEN plastic ball-shaped plastic piece that was in two parts laying in the bottom of the door. Could that be part of the issue? Where do I get repair parts for these windows??? Thanks!