Liftmaster K09-50129, GEAR BOX COVER, Q073
The LiftMaster K09-50129 Q073 gear box cover is a protective replacement cover for compatible LiftMaster HCT overhead gate operators. On an overhead gate operator, the gearbox area is a key mechanical section that needs to stay protected from debris, accidental contact, and weather exposure. A missing or damaged cover can allow dirt to collect around moving parts and may leave hardware more vulnerable to corrosion or impact. This part restores the protective cover area but does not replace worn gears, bearings, seals, or the gear reducer itself. K09-50129 is commonly tied to HCT overhead gate operator service parts and Q073 cross-reference listings. It should be matched by part number and operator diagram because other covers in the HCT family may look similar but have different size or mounting patterns.
Compatible With
- LiftMaster HCT overhead gate operators
- HCT Series overhead gate operator parts diagrams listing Q073
- Select Hercules/HCT overhead gate applications where K09-50129 is called out
Compatibility should be verified by the original part number, operator model, and LiftMaster parts diagram. Similar-looking gate and access-control parts may not be interchangeable across model generations.
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster / Chamberlain Group |
| Product Type | Gear box cover |
| Part Number | K09-50129 |
| Alternate / Related Number | Q073 |
| Application | Overhead gate operator gearbox-area cover replacement |
| Compatible Operator Type | HCT overhead gate operators |
| Common Model Reference | LiftMaster HCT |
| Notes | Cover only; does not include gearbox, gears, motor, or control electronics |
Also Known As / Related Part Numbers
- K09-50129
- Q073
- 09-50129
- LM-K09-50129
- LiftMaster Q073
- Gear box cover HCT
- Gearbox cover Q073
Related numbers are included to help with part lookup and cross-reference searches. Do not treat a related number as a direct replacement unless it matches the original parts diagram for your equipment.
Technician Note
Before replacing this part, inspect the surrounding hardware and the reason the original part failed. Bent brackets, worn bushings, loose fasteners, water intrusion, damaged covers, gate bind, or incorrect previous repairs can cause repeat failures even after the correct replacement part is installed.
Before Ordering
- Confirm the manufacturer part number on the original part or parts diagram.
- Verify the exact operator, keypad, telephone entry, or access-control model.
- Compare mounting points, cover shape, length, handedness, and related hardware where applicable.
- Check whether companion parts are damaged or missing.
- Do not bypass required safety devices or modify factory safety-related assemblies.
Professional Advisory
Gate and commercial operator parts can involve heavy moving assemblies, stored mechanical force, and high-voltage wiring. If the system has unsafe movement, missing safety devices, damaged wiring, or alignment problems, have the equipment inspected by a qualified gate or commercial door technician before returning it to service.
Product Questions & Answers
What is the K09-50129 Q073 used for?
It is a replacement gear box cover for compatible LiftMaster HCT overhead gate operators.
Is this the complete gearbox assembly?
No. K09-50129 is the protective cover only. It is not the gearbox, gear reducer, motor, or internal gear set.
Which model family is this cover commonly associated with?
It is commonly associated with LiftMaster HCT overhead gate operator parts references.
When should this cover be replaced?
Replace it when the original cover is cracked, missing, bent, corroded, or no longer fastening securely.
What should I inspect while replacing the cover?
Check gearbox condition, mounting screws, nearby covers, signs of oil leakage if applicable, debris buildup, and any impact damage around the operator.
