Liftmaster K12-2125, FLANGED BALL BEARING, 1-1/4" BORE
The LiftMaster K12-2125 is a 1-1/4 inch bore flanged ball bearing used to support a rotating shaft in select LiftMaster swing gate operator assemblies. A good bearing keeps the shaft aligned, reduces friction, and helps prevent side-load wear on the surrounding drive parts.
This bearing is commonly tied to SW490GL swing gate applications and may be found in related high-torque swing gate parts diagrams. Because bearing style, bore size, flange geometry, and mounting location all matter, the correct replacement should be confirmed from the operator manual rather than selected by bore size only.
Common Replacement Reasons
- Noisy or rough shaft rotation
- Visible bearing wear or corrosion
- Excessive shaft play near the bearing
- Drive assembly drag or binding
- Preventive replacement during swing gate operator rebuild
Compatible With
Common Compatible Models
- LiftMaster SW490GL swing gate operator
- Select LiftMaster SW490 / SW490GL swing gate assemblies where the parts diagram lists 12-2125 or K12-2125
Additional Model Families to Verify
- Select heavy-duty LiftMaster / Elite / OSCO swing gate operator applications that call for a 1-1/4 inch bore flanged bearing
- CSW200 style references should be verified by parts diagram before ordering
Important Compatibility Notes
Do not order by bore size alone. Confirm the flange style, bearing width, and mounting location.
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster / Chamberlain Group |
| Product Type | Flanged ball bearing |
| Part Number | K12-2125 |
| Bore Diameter | 1-1/4 inch |
| Application | Swing gate operator shaft support |
| Compatible Operator Type | Select LiftMaster swing gate operators |
| Notes | Verify flange configuration and parts diagram before ordering |
Also Known As / Related Part Numbers
- K12-2125
- 12-2125
- LM-K12-2125
Technician Note
A failed bearing can damage shafts, sprockets, and collars. If the removed bearing is loose or noisy, inspect the mating shaft surface before installing the replacement.
Before Ordering
- Match the manufacturer part number to the operator parts diagram before ordering.
- Compare the shaft, bearing, bushing, or gasket dimensions against the removed part.
- Check the operator model, series, and generation because similar LiftMaster mechanical parts may not interchange.
- Inspect nearby collars, sprockets, chains, keys, fasteners, and bushings for wear before reassembly.
- For commercial gate or barrier operators, have a qualified technician handle service if the gate movement is unsafe or the drive system is under load.
Professional Advisory
Commercial gate and barrier operator drive parts should be serviced with the gate secured, power disconnected according to the operator manual, and all safety devices left in proper working order. Do not bypass entrapment protection or operate a damaged gate system to test a mechanical repair.
Product Questions & Answers
What size is the K12-2125 bearing?
It is commonly listed as a flanged ball bearing with a 1-1/4 inch bore.
What model is K12-2125 commonly associated with?
It is commonly associated with LiftMaster SW490GL swing gate operator applications.
Can I use any 1-1/4 inch bearing instead?
No. The bore size is only one part of the fit. The flange style, width, and mounting location must also match.
What symptoms point to a worn bearing?
Noise, rough rotation, shaft play, corrosion, or binding around the drive section can point to bearing wear.
What related number should I search?
The common related number is 12-2125.
