Each of the two serrated rollers must "walk" around the torsion spring as you open and close the door. You can rotate each gear to another tooth (which is prbably still painted) or put a smear of lithium grease at the contact point (smearing it anywhere else simply messes things). Add a drop or two of oil to the pivot of each wheel and another down the side of the torsion spring where it bears against the casting (it has to rotate against that surface). A few cycles of the door and things should be quiet as new.