LiftMaster K15-48B24GXX 48B24T Sprocket, 3/4 Inch Bore
The LiftMaster K15-48B24GXX sprocket is a precision drive component used in select LiftMaster commercial door operator drivetrain assemblies. The part is commonly described as a 48B24T sprocket with a 3/4 inch bore, meaning it is intended for a specific chain pitch/tooth-count/bore combination in the operator output drive. In commercial trolley operators, sprockets must match the output shaft and chain system exactly so power transfers smoothly without chain misalignment or premature wear. A sprocket with the wrong bore, tooth count, hub profile, or chain size can damage the chain, shaft, bearings, or operator frame. This part is commonly referenced with medium-duty commercial operator output shaft kits and should be confirmed against the unit parts list before installation.
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.
- Select LiftMaster medium-duty commercial door operators
- Select LiftMaster MT/BMT output shaft and chain drive assemblies when parts diagram confirms
- K72-12472 output shaft kit applications when 15-48B24GXX is listed
- K72-33873 output shaft kit applications when 15-48B24GXX is listed
- MT5011U style output shaft breakdowns where O5 is 15-48B24GXX
- Commercial operator drive assemblies requiring a 48B24 x 3/4 inch sprocket
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster |
| Product Type | Replacement Sprocket |
| Part Number | K15-48B24GXX |
| Sprocket Type | 48B24T |
| Bore Size | 3/4 inch |
| Application | Commercial operator output shaft and chain drive assemblies |
| Compatible Operator Type | Select LiftMaster medium-duty commercial door operators |
| Notes | Match chain size, tooth count, bore, 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.
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 size sprocket is K15-48B24GXX?
It is commonly described as a 48B24T sprocket with a 3/4 inch bore.
Where is this sprocket used?
It is used in select LiftMaster medium-duty commercial operator output shaft and chain drive assemblies when the parts diagram specifies 15-48B24GXX.
Is this related to the K72-12472 output shaft kit?
Yes. The 15-48B24GXX sprocket appears in related MT output shaft kit breakdowns that also reference K72-12472 and 11-10319.
Can I match this sprocket by tooth count only?
No. Tooth count, chain pitch, bore size, hub style, shaft fit, and parts diagram must all match.
What symptoms can a worn sprocket cause?
A worn sprocket can cause chain noise, chain jump, uneven travel, accelerated chain wear, or poor power transfer through the operator drive system.
