BBMW (77-95) Belt Adjusting Nut Toothed for Alternator ac belt adjustment e28 e30 ReviewbP PP BMW (77-95) Belt Adjusting Nut Toothed for Alternator ac belt adjustment e28 e30 PAdjusting Nut Toothed Nut for Adjusting Alternator Belt, Power Steering Belt and AC BeltPBMW part# 12 31 7 677 914, check fit below.PGenuine BMW part, recently made: not been lying around.