So, lately, when I shut my driver's side door, the mirror will drift up and I have to readjust it. Does anyone know what I have to replace/repair in there to make it stop doing this? I know how to get into there by moving the mirror all the way up or down and removing the little cross bar, but I don't really know what I'll be looking for in there, or even if parts will be available.

Thanks for any help!