The Genie 39278R.S Belt Drive Sprocket is a genuine OEM replacement component for select Genie belt-drive garage door openers. Located at the top of the operator head, this toothed sprocket engages the drive belt to transfer motor power to the rail and trolley, restoring smooth, quiet door travel when the original sprocket becomes worn or damaged. It is intended for residential garage door opener systems and should be chosen only when your opener’s parts list or service manual specifically calls out 39278R.S (also referenced as 39278RS).
Use this factory replacement part to resolve symptoms such as belt skipping, chirping, or intermittent travel caused by a stripped or cracked sprocket. Installation is a mechanical swap at the motor head and does not require programming; after installation, follow Genie’s instructions to set or verify travel limits and force. For safety, disconnect power to the opener, ensure the door is balanced and secured, and follow all manufacturer service procedures. This replacement part is designed for Genie belt-drive models that list 39278R.S in their documentation and is not intended for chain-drive openers or models that specify a different sprocket assembly. For compatibility, confirm against your opener’s exact model number and parts diagram or contact Genie support.
