Sounds like you need to do the Delrin bushing mod. Eckler's sells 'em. Ask the Junk man, like he said, most of us have worked on those headlights so many times we can do 'em hung upside down, drunk, blindfolded and using just our toes.

Do a search here for Delrin and you will find reams of info on how to do it. I even had a machinist friend machine new metal bushings that go in the horseshoe brackets and they run in synch and are perfect now. What I found when I took mine apart was sinful. Some clown put two each nuts glued together with gray silicone in each corner in the light motor for a total of 12 nuts. What a mess!

Lemme know if you need help, I have a full folder on my computer of files that cover lights.