MGJ5011, MGJ5023, MGJ5025 Jackshaft Parts

LiftMaster MGJ5011 Replacement Parts — Medium-Duty Gear-Reduced Jackshaft Operator

Genuine LiftMaster replacement parts for the MGJ medium-duty gear-reduced jackshaft operator. The MGJ5011 is the most common version — 1/2 HP, 120V, single phase. Use the exploded diagram to identify your part by its key number, then match it to the tables below.

The MGJ drives through a 45:1 gear reducer and a compound sprocket rather than a belt and clutch, so its drive-train parts do not interchange with the MT or MJ. Several early MGJ castings have been discontinued by LiftMaster and are marked below — they are listed so you can identify what you have.

Models Covered

MGJ5011 (1/2 HP, 120V, 1PH — most common), MGJ5023 (208/230V, 3PH), MGJ5025 (230V, 50Hz), MGJ5038 (380V, 3PH, 50Hz)

Replacement Parts

Service Kits

The motor’s part number is printed on the motor’s own data label. If you can reach it, read the number straight off the label and match it above — that is the most reliable way to order the right motor.

Electrical box parts. The MGJ was built with the shared medium-duty logic control box and with its own MGJ-specific mechanical box. The mechanical box has different contents for single-phase and three-phase units — check your unit before ordering.

Electrical Box — Logic Control

Electrical Box — Mechanical, Single Phase

Electrical Box — Mechanical, Three Phase

Electrical Box — Limit Shaft and Switch Kits