Liftmaster K177A0112, TROLLEY SPRING
The LiftMaster K177A0112 trolley spring is a small mechanical spring used in the trolley area of select residential garage door openers. In many applications, the spring helps the trolley or release mechanism return and stay properly positioned as the opener moves the door. When the spring is stretched, broken, corroded, or missing, the trolley can feel loose, fail to reconnect cleanly, rattle during travel, or create inconsistent manual release behavior. This part is commonly associated with LiftMaster, Chamberlain, and Sears Craftsman openers using compatible Chamberlain Group trolley hardware. Since spring length, hook shape, and tension matter, verify the original part number and trolley assembly before ordering. If the trolley is cracked or worn, replacing only the spring may not correct the problem.
Compatible With
Common Compatible Models and Applications
- Select LiftMaster residential garage door opener trolley assemblies
- Select Chamberlain residential garage door opener trolley assemblies
- Sears Craftsman openers manufactured by Chamberlain Group when the trolley diagram calls for this spring
- Applications using 41B3244-style trolley hardware where this spring is specified
Additional Model Families to Verify
- Residential chain and belt drive opener families that list K177A0112, 177A112, or 177A0112
- Older trolley assemblies using related spring numbers 62274, 062274, 132C2180, or 177A78
Important Compatibility Notes
- Verify the trolley style before ordering
- Do not substitute a spring with a different length, tension, or hook design
- Inspect the trolley body, release rope, and rail connection if the spring failed
Features and Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster / Chamberlain Group |
| Product Type | Trolley spring |
| Part Number | K177A0112 |
| Application | Residential garage door opener trolley and release hardware |
| Compatible Operator Type | Select LiftMaster, Chamberlain, and Craftsman residential openers |
| Length | Commonly listed around 2 inches; verify current part |
| Notes | Match by trolley assembly and parts diagram |
Also Known As / Related Part Numbers
- K177A0112
- 177A112
- 177A0112
- 62274
- 062274
- 132C2180
- 177A78
- LiftMaster 177A112
- Chamberlain 177A112
Technician Note
Match this part to the exact opener model, original part number, and replacement parts diagram. Similar LiftMaster and Chamberlain parts can look alike but may not interchange across rail styles, board generations, safety systems, or operator families.
Before Ordering Checklist
- Confirm the opener or operator model number before ordering
- Compare the original part number or marking to the related numbers listed above
- Check the replacement parts diagram for the exact hardware, board, sensor, or rail assembly
- Inspect surrounding parts for wear so the replacement is not installed into a failing assembly
- For electrical, logic board, or safety-device work, shut off power and use a qualified technician when needed
Important Ordering Warnings
- Verify exact model and parts diagram before ordering
- Do not substitute similar-looking parts without confirming dimensions, frequency, rail type, or board generation
Professional Advisory
Garage door and gate operator repairs can involve spring tension, moving doors, high-voltage wiring, monitored safety devices, and heavy gate hardware. If the repair involves unsafe movement, electrical testing, or required entrapment protection, have the system inspected by a qualified gate or garage door technician.
Product Questions and Answers
What does the K177A0112 trolley spring do?
It helps the compatible trolley or release mechanism return and stay properly positioned during opener operation.
What are signs of a bad trolley spring?
A stretched, broken, or missing spring may cause rattling, poor release action, loose trolley movement, or unreliable reconnection.
Is K177A0112 the same as 177A112?
Yes. 177A112 is commonly listed as a related number for K177A0112.
Can I use a spring that looks close?
No. Spring length, tension, and hook shape matter. Use the spring called out by the parts diagram.
Should I replace the trolley too?
If the trolley body is cracked, worn, or not latching correctly, replacing only the spring may not solve the issue.
