The smaller of these two gears is for the Forward/Backward Adjustment Motor. The larger gear is for the Front or Rear Seat Height Adjustment Motor. Seat Adjuster Motor Repair Two Plastic Gear Set Compatible With Chev.rolet Tahoe GM.C Yukon 2007-2014 Replacement parts Compatible With OEM: - Compatible With Che.vrolet Tahoe 2007-2014 GM.C Yukon 2007-2014 Notice: The smaller of these two gears is for the Forward/Backward Adjustment Motor. The larger gear is for the Front or Rear Seat Height Adjustment Motor.