The LiftMaster 310-80051 Step Key is a genuine OEM replacement part designed to lock a sprocket, gear, or coupling hub to a keyed shaft in select LiftMaster commercial door operators. By positively engaging both the shaft and the mounted component, it ensures reliable torque transfer, prevents slippage under load, and maintains alignment within the drive assembly. This makes it essential for restoring proper operation after drivetrain service or component replacement on commercial and industrial overhead door systems.
Engineered for direct-fit service work, the 310-80051 is used where a stepped profile is required to match differing keyway profiles between the shaft and hub. Typical applications include jackshaft, trolley, and hoist operators in the LiftMaster commercial lineup that specify this part number in their service documentation. For installation, align the stepped faces with the corresponding keyways, fully seat the hub, and secure any associated set screws or fasteners per the model’s service manual. Always disconnect power, lock out/tag out, and support the door or load before servicing. Verify compatibility by referencing your operator’s parts list to ensure this OEM step key matches the required specification.