A jackshaft garage door opener mounts on the wall beside the door and turns the door’s torsion shaft directly, instead of hanging from the ceiling like a trolley opener. That keeps the ceiling clear for lights, racking, cranes or a high-lift track, which is why jackshaft operators are common in warehouses, shops and plants.
These are four LiftMaster jackshaft models we supply and install for commercial doors. If you’re not sure which one fits your door, call us with the door type, size and how often it runs.
The four models side by side
| Model | Built for | Motor | Notes |
|---|---|---|---|
| LJ8900W | Light-duty sectional doors: standard, vertical and high-lift | 3/4 HP DC, 120V single-phase | Up to 10 cycles per hour. Soft start and stop. |
| LJ8950W | Commercial rolling sheet doors | 24V DC, variable speed | Up to 10 cycles per hour. Reverses the door if it senses slack in the cable. |
| MJ | Medium-duty commercial doors | 1/2 HP, 115V single-phase | Logic control board, adjustable friction clutch and brake. |
| MGJ | Rolling grilles and shutters | 1/2 HP single-phase | Gear reducer in an oil bath, floor-level disconnect for manual operation. |
Specs from LiftMaster product literature published by LiftMaster dealers.
LiftMaster LJ8900W
The LJ8900W is a light-duty jackshaft operator for commercial sectional doors with torsion springs, including vertical-lift and high-lift doors. Its compact size suits openings with limited headroom or an obstructed ceiling. It runs on a DC motor with soft start and stop and is rated for up to 10 cycles per hour at peak.
- Security+ 2.0 rolling-code remotes
- myQ phone control with the LiftMaster internet gateway
- Photo eyes included, and an optional battery backup to keep the door working in a power outage
- UL 325 and CSA listed
LiftMaster LJ8950W
The LJ8950W is the light-duty jackshaft operator for rolling sheet doors, like the roll-up doors on storage units and small shops. It mounts on the wall on either side and drives the door by chain and sprocket. A cable tension monitor reverses the door if it detects slack, and it comes with photo eyes and an emergency disconnect for manual operation.
LiftMaster MJ and MGJ
The MJ is a medium-duty jackshaft operator with LiftMaster’s Logic control board, a 1/2 HP motor, an adjustable friction clutch and a solenoid brake. The board supports timer-to-close from 5 to 60 seconds when monitored safety devices are installed.
The MGJ is the gear-reduced version for rolling grilles and shutters. It uses a worm gear reducer running in oil, and a floor-level disconnect lets staff open the grille by hand if the power is out. Both come with a three-button control station.
Picking the right operator
The main questions are the door type (sectional, rolling sheet or grille), the door size and weight, and how many times a day it opens. A light-duty operator on a door that cycles all day will wear out early, so tell us how the door is used. We’ll match the operator to the door and give you a quote before anything is ordered.
Service and repair
We repair LiftMaster commercial operators too: limit adjustments, photo eye problems, worn clutches and brakes, and boards that need replacing. Same-day repair is available for commercial doors. See commercial garage door repair.