Liftmaster K15-25B23EEX, LIMIT SWITCH SPROCKET, 5/8" BORE, Q131
The LiftMaster K15-25B23EEX is a small but important limit switch drive sprocket used in select older LiftMaster and Elite slide gate operators. In the limit system, the sprocket works with the limit chain or timing hardware so the operator can count and control gate travel. When this part wears down, loosens on the shaft, or no longer meshes correctly, the operator may fail to stop at the set open or close position, may drift out of adjustment, or may require repeated limit readjustment. This is not the large gate drive sprocket that pulls the gate chain; it is a limit-control component. Match it carefully by part number, Q-number reference, bore size, and the operator parts diagram because several limit sprockets in the same product family look similar but are not interchangeable.
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster / Chamberlain Group |
| Product Type | Limit switch drive sprocket |
| Part Number | K15-25B23EEX |
| Common Reference | Q131 |
| Bore | 5/8 inch |
| Application | Limit switch drive system |
| Compatible Operator Type | Select Robo Slide gate operators |
| Notes | Match by original part number, bore size, and parts diagram |
Compatible With
Common Compatible Models
- Select LiftMaster Robo Slide gate operators
- Select Elite Robo Slide gate operators using Q131 limit switch drive sprocket
- Older perimeter access slide gate systems where K15-25B23EEX is shown in the parts diagram
Important Compatibility Notes
- Verify 5/8 inch bore before ordering
- Confirm the operator calls for Q131 or K15-25B23EEX
- Do not substitute for Q016, Q033, K15-35B13AXR, or K15-35B17LGF limit sprockets unless the parts diagram confirms it
Also Known As / Related Part Numbers
- K15-25B23EEX
- 15-25B23EEX
- Q131
- LiftMaster Q131
- Limit switch drive sprocket
- Limit switch sprocket 5/8 inch bore
Technician Note
If the gate limits will not hold adjustment, inspect the limit chain, limit nuts, sprocket set screw, shaft wear, and limit switch assembly at the same time. Replacing only the sprocket may not solve the issue if the surrounding limit hardware is loose or damaged.
Before Ordering Checklist
- Confirm the original part number or Q131 reference
- Check the bore size and shaft fit
- Inspect the limit chain and limit switch assembly for wear
- Verify the operator model and parts diagram
- Do not order by appearance only
Professional Advisory
Limit-system repairs should be performed with power disconnected and the gate secured. If the operator is overtraveling, moving unpredictably, or has damaged safety devices, have the gate inspected by a qualified gate technician before returning it to service.
Product Questions & Answers
What does this sprocket do?
It drives or tracks the limit switch mechanism so the operator can stop the gate at the programmed open and close positions.
Is K15-25B23EEX the same as Q131?
Q131 is a common reference for this limit switch drive sprocket, but the original parts diagram should still be checked before ordering.
Will this fit an SL3000 operator?
Do not assume it fits SL3000 units. SL3000 operators commonly use different limit sprocket references such as Q016 or K15-35B13AXR depending on the assembly.
What symptoms can a worn limit sprocket cause?
Common symptoms include drifting limits, missed stops, repeated limit adjustments, or visible sprocket wear in the limit drive area.
Should I replace the limit chain too?
If the chain is stretched, damaged, rusty, or not meshing cleanly, it should be inspected and replaced as needed along with the worn sprocket.
