Fleck 9000,9100,9500 Drive Motor 120v 60 Hz ( 18738 or 61633-01 ) , used to move pistons during regeneration. Older part numbers 14927 and 17610.Be Sure to Check the Condition of the Middle Drive Gear (1513502 ), as this can sometimes be the real reason the valve is not turning.Also, the Gear usually strips because the Main Pistons and Seals need to be replaced.