Go ahead and clean the rollers on the regulator that slide in the glass channel and clean the short piece of rail inside the door that is welded to the door frame. Just a couple of quick pics...
I used WD-40 and brake clean to remove grease and lubricate the rollers and channels.
Use a pic and brake cleaner to clean the 3 holes in the roller. The straw from the WD-40 can works well on the brake cleaner to insert it in the 3 holes and flush the junk out. Wear gloves and safety glasses to keep the brake clean out of your eyes as it passes through the small holes in the roller and shoots back out in your face. Protect your paint also.
After. Once cleaned, apply some WD-40 or white lithium grease to holes in rollers and work them around to evenly coats the ball inside.
After cleaning window channel attached to glass.
