LiftMaster K75-10170 Trolley Slider Assembly Kit
The LiftMaster K75-10170 Trolley Slider Assembly Kit is the moving carriage-style component used inside select LiftMaster commercial trolley operator rail systems. On compatible operators, the drive system moves the trolley slider along the rail, and the trolley transfers that movement through the straight or curved door arm to open and close the commercial sectional door. A worn trolley slider can create rough travel, chatter, uneven door movement, loose linkage, or failure to pull the door properly. This kit is often serviced along with the front idler trolley, door arm hardware, track spacers, and chain adjustment hardware because those parts work together to keep the operator rail aligned and the door arm geometry correct. The K75-10170 should be matched by the operator parts diagram, not only by appearance, because similar LiftMaster commercial rails can use different slider assemblies depending on series and generation.
What This Part Does
This replacement part restores a specific mechanical function in the commercial operator system. On compatible LiftMaster equipment, it helps keep the rail, trolley, door arm, or drivetrain aligned so the operator can move the door smoothly and reliably. When this part is worn or damaged, the operator may become noisy, bind, travel unevenly, or place extra stress on connected hardware.
Compatible With
This part is commonly associated with the following LiftMaster commercial operator models, series, or related rail/drivetrain assemblies. Compatibility can depend on operator generation, rail configuration, duty rating, and the exact parts diagram.
- LiftMaster T commercial trolley operators
- LiftMaster MT medium-duty trolley operators
- LiftMaster GT industrial trolley operators when parts diagram confirms
- LiftMaster TDC commercial trolley operators
- LiftMaster Logic 4.0 commercial trolley operator platforms when specified
- LiftMaster Logic 5.0 commercial trolley operator platforms when specified
- LiftMaster MAXUM commercial trolley operator platforms when specified
- Common model references include T33, T3311, T50, T5011, T75, T7511, MT3311, and MT5011 when confirmed by rail and parts diagram
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster |
| Product Type | Trolley Slider Assembly Kit |
| Part Number | K75-10170 |
| Application | Replacement trolley slider/carriage for commercial trolley operator rail systems |
| Compatible Operator Type | Select LiftMaster T, MT, GT, TDC, Logic 4.0, Logic 5.0, and MAXUM trolley operators |
| Related Numbers | 75-10170, 7510170, 307085008, 08-10169, 085008 |
| Notes | Verify rail style, operator model, and parts diagram before ordering. |
Also Known As / Related Part Numbers
This item may be searched or referenced under the following part numbers, kit numbers, catalog aliases, or related components. Related numbers are not always interchangeable unless the operator parts diagram confirms the replacement.
- K75-10170
- 75-10170
- 7510170
- 307085008
- 08-10169
- 085008
- LiftMaster trolley slider assembly
- Commercial trolley slider kit
Technician Note
Do not order this part by appearance alone. Commercial trolley operator hardware and drivetrain parts can look similar while using different dimensions, bore sizes, rail layouts, chain sizes, or mounting geometry. Verify the original part number, operator model, rail or drivetrain layout, horsepower/duty rating where relevant, and the replacement parts diagram before installing. If the door is binding, out of balance, or has damaged track/hardware, correct the door issue before replacing operator parts.
Before Ordering, Confirm
- Original part number or related kit number matches the product being ordered
- LiftMaster operator model and duty rating match the parts diagram
- Rail style, door arm geometry, output shaft layout, sprocket size, or chain size matches where applicable
- Package contents match what is needed for the repair
- Door balance, track condition, and connected hardware have been inspected
- No similar-looking but different LiftMaster part is being substituted by mistake
Professional Advisory
Commercial door operator service involves moving door systems, chains, sprockets, door arms, and rail hardware. Disconnect power before service and keep hands clear of moving parts. After installation, inspect the full door travel, verify hardware alignment, check chain or trolley tension where applicable, and test the door system from a safe location. If the operator has electrical damage, unsafe door movement, broken springs, damaged track, or missing safety devices, have the system inspected by a qualified commercial door technician.
Important Ordering Warnings
- This part is not universal for all LiftMaster operators.
- Model series names such as T, MT, BMT, GT, TDC, or MAXUM still require parts diagram verification.
- Residential garage door opener parts should not be substituted for commercial trolley operator parts.
- For shaft and sprocket components, bore size, tooth count, chain pitch, and kit contents must match.
- For rail and door arm parts, rail layout, door height, and linkage geometry must match.
Questions & Answers
What does the K75-10170 trolley slider do?
The trolley slider rides in the operator rail and connects the drive system to the door arm so the commercial sectional door can open and close.
Which LiftMaster operators commonly use K75-10170?
It is commonly associated with select LiftMaster T, MT, GT, TDC, Logic 4.0, Logic 5.0, and MAXUM trolley operator systems, including some T33, T50, T75, MT3311, and MT5011 style references.
Is K75-10170 the front idler trolley?
No. K75-10170 is the trolley slider assembly. The front idler trolley is a different part commonly associated with K75-10174.
What symptoms point to a worn trolley slider?
Common signs include noisy rail travel, sloppy linkage, binding, uneven door movement, cracked slider material, or a trolley that does not pull the door arm smoothly.
What should be checked before replacing the slider?
Check rail alignment, chain tension, front idler hardware, door arm hardware, and door balance. A binding door or misaligned rail can damage a new slider.
