LiftMaster K77-31222 Hardware Kit for GH Logic 3 Commercial Door Operators
The LiftMaster K77-31222 is a replacement hardware kit commonly listed for LiftMaster GH, L3 commercial door operator applications. GH operators are gearhead hoist commercial operators used where a heavier door or higher duty commercial installation requires a gear-reduced operator with manual hoist capability.
Because GH operators are built differently from standard H hoist and J jackshaft units, the hardware kit must be matched carefully. The part number K77-31222 points to the GH Logic 3 hardware path and should not be treated as a universal hardware kit for every side-mounted commercial operator.
This item is a service hardware kit only. It does not include a gear reducer, motor, brake, clutch, limit assembly, control board, or complete GH operator. Use it when the parts diagram for the exact GH operator identifies K77-31222.
Compatible With / Common Applications
Commonly associated with the following applications when confirmed by LiftMaster parts breakdown:
- LiftMaster GH commercial gearhead hoist operators, Logic 3 / L3 applications
- Commercial overhead door and rolling door service repairs where the GH operator diagram lists K77-31222
- Heavy-duty side-mounted GH operator hardware repairs by exact part number
- Not a confirmed substitute for H hardware kits K77-10895 or K77-31372
- Not for J, HJ, T, GT, APT, SD, GSD, MJ, MH, MGJ, or residential garage door openers unless the diagram specifically lists K77-31222
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster |
| Product Type | Commercial operator hardware kit |
| Part Number | K77-31222 |
| Application | GH gearhead hoist commercial door operator hardware |
| Compatible Operator Type | Select LiftMaster GH Logic 3 commercial operators |
| Logic / Generation | L3 / Logic 3 reference |
| Notes | Hardware kit only; verify by parts diagram |
Also Known As / Related Part Numbers
- K77-31222
- LM-K77-31222
- LIF-K77-31222
- OCDPLM-K77-31222
- LiftMaster GH L3 hardware kit
- LiftMaster Hardware GH Logic 3
- Related but not interchangeable without diagram: K77-31372 H L3
- Related but not interchangeable without diagram: K77-31224 J L3
Technician Note
GH hardware is tied to a heavier gear-reduced operator path. If the original hardware is damaged, inspect the gear reducer output, brake function, chain path, and door load before replacing parts.
Before Ordering
- Verify the operator is a GH commercial gearhead hoist model.
- Confirm the parts diagram lists K77-31222.
- Check the operator generation; this row is written for GH, L3 references.
- Compare the old hardware with the diagram before ordering.
- Inspect related chain, sprocket, brake, and door balance issues that may have caused the hardware failure.
Professional Advisory
GH commercial operators are used on heavy doors and can involve high mechanical loads. Use a qualified commercial door technician if the door is hard to move, the brake is not holding, or the operator hardware shows unusual wear.
Product Questions & Answers
What does GH mean on this part?
GH refers to LiftMaster gearhead hoist commercial door operator applications. K77-31222 should be matched to GH Logic 3 parts diagrams.
Is K77-31222 for a standard H hoist operator?
No. Standard H hoist operators use different hardware references. K77-31222 is the GH, L3 hardware path.
Does this kit include the gear reducer?
No. It is a hardware kit only and does not include the gear reducer, motor, brake, or electrical controls.
Can this be used on a Logic 5 GH operator?
Only if the Logic 5 parts diagram specifically lists this part. The L3 reference means generation should be checked before ordering.
What related parts should be checked?
Inspect the drive chain, sprockets, brake assembly, shaft alignment, gear reducer output, and door balance during the repair.
