The Genie 28021A.S Sprocket, Belt Drive is a genuine OEM replacement component for select Genie belt-drive garage door openers. This sprocket meshes with the drive belt to transfer motor power to the trolley, helping ensure smooth, reliable travel of the door. It is commonly replaced when the original sprocket shows tooth wear, stripping, or abnormal noise that leads to belt slippage or inconsistent door movement. As an authentic Genie replacement part, it is designed to restore proper operation in residential belt-drive systems that specifically call for part number 28021A.S in their parts list or service manual.
Use only on compatible Genie belt-drive models; this sprocket is not interchangeable with chain-drive components. For best results, verify compatibility by matching 28021A.S to your opener’s model number and parts diagram. Installation typically involves disconnecting power, relieving belt tension, removing the rail cover and retainer, swapping the sprocket, then re-tensioning the belt and checking alignment. After replacement, test safety reversal and recalibrate travel and force limits per the manufacturer’s instructions. If you are not experienced with garage door systems, consult a qualified technician, as the door mechanism and springs can be hazardous if serviced improperly. Keywords: Genie 28021A.S, Genie sprocket, belt drive sprocket, Genie garage door opener replacement part, OEM Genie belt-drive repair, residential garage door opener component.