LiftMaster 1240, 1245, 1246, 1250 Chain Parts
LiftMaster 1240, 1245, 1246 and 1250 Replacement Parts
This page covers the 1240, 1240R, 1245, 1245R, 1245LK, 1246, 1246R and 1250 chain drive openers. Everything for them is here: the motor unit, the gear and sprocket, the rail and chain, the safety sensors, the door hardware, the wall control and the remote. Each section has its own diagram, and the reference numbers are specific to the diagram directly above them.
Motor runs but the door does not move? On these openers that is almost always the gear and sprocket assembly — the nylon gear strips. It is part 041C4220A, it fits most LiftMaster chain drives, and we stock it in both factory and aftermarket versions. See section 2.
1. Motor Unit
First part of number below corresponds to diagram number above:
| Ref | Part # | Description |
|---|---|---|
| 01 | 041A4208-2 | Chain spreader with screws |
| 01A | K031D0380M | Sprocket cover — single sprocket units |
| 02 | 041A3261-1 | Dual gear kit |
| 02A | 041C4220A | Gear and sprocket assembly |
| 03 | 041A2817 | Gear kit |
| 04 | 041B4245-1 | Line cord, 6 ft |
| 07 | 041C0279 | Light socket |
| 08 | K108D0034 | Light lens — two light operators, sold individually |
| 08A | K108D0036-2 | Light lens — one light operators |
| 09 | K030B0532-1 | Capacitor |
| 10 | K012A0373 | Capacitor bracket |
| 11 | 041A3150 | Terminal block with screws |
| 12 | 041D3058 | Universal replacement motor and bracket assembly, 1/2 HP |
| 14 | 041A2818 | Limit drive gear |
| 15 | 041D3452 | Limit switch assembly |
| 16 | 041C4398A | RPM sensor assembly |
| 17 | 041C4246 | Wire harness, 1993 to current |
| 18 | 041A2817 | Gear kit including bearings |
| 22 | 41A3673 | End panel — two light operators |
| — | 041A5484 | End panel |
| — | 041D3452-2 | Limit switch kit |
| — | 041D5563 | Motor, 3/4 HP |
| — | 041A2825 | Opener assembly hardware kit |
Two motor options. Ref 12 is the 1/2 HP motor and bracket; the 041D5563 is the 3/4 HP. Check the horsepower on your motor unit label and order to match. 041A2817 is called out twice, at 03 and 18 — the same gear kit either way.
Logic boards for these models are discontinued. All five versions — 41A5021, 041A5021-1i, 041A5021-1M-315, 041A5021-H-315 and 41A5021-i — are no longer manufactured and we do not stock a replacement. Everything else on this diagram is available. If your board has failed, call (866) 965-5599 before ordering anything else. The older 30B366 1/4 HP capacitor is also discontinued; use the K030B0532-1 above.
2. Gear and Sprocket — Factory or Aftermarket
The nylon gear on the 041C4220A is the most common failure on these openers, and the part fits most LiftMaster chain drives. If the motor runs and the door does not move, this is what to order. We stock both the genuine LiftMaster assembly and a lower cost aftermarket version built to the same dimensions.
| Part # | Description | Factory (OEM) | Aftermarket |
|---|---|---|---|
| 041C4220A | Gear and sprocket assembly | Factory assembly | Aftermarket assembly |
Fit the new gear with the opener disconnected from the door, and grease the worm before reassembly — running it dry is what strips the next one. The 041A2817 gear kit is the alternative if only the gear itself has failed.
3. Rail, Chain and Trolley
First part of number below corresponds to diagram number above:
| Ref | Part # | Description |
|---|---|---|
| 01 | 004A1008 | Master link kit |
| 03 | 041A4813 | Cable pulley bracket |
| 04 | 041A3489 | Trolley assembly |
| 05 | 041D3484 | Chain assembly — 7 ft door |
| 05 | 041D3483 | Chain assembly — 8 ft door |
| 05 | 041D3485 | Chain assembly — 10 ft door |
| 06 | 83A11-2 | Rail grease |
| 11 | K144C0056 | Idler pulley |
| 16 | 041B0035B | Curved door arm |
| 17 | 4178B0034B | Straight door arm section |
| — | 041A8094 | Door arm kit — curved and straight sections together |
The chain assembly is sized to your door height. Measure the door opening, not the rail. A slack chain can usually be re-tensioned rather than replaced — replace it if links are stiff, the cable is frayed, or the chain has jumped the sprocket. Browse all chain and master links.
Complete rail assemblies
| Ref | Part # | Description |
|---|---|---|
| — | 1707LM | One piece T rail, 7 ft |
| — | 1708LM | Complete chain drive rail assembly, 8 ft door |
| — | 3707CH | Chain I beam rail system, 7 ft |
| — | 3708CH | Chain I beam rail system, 8 ft |
| — | 3710CH | Chain I beam rail system, 10 ft |
4. Safety Sensors and Brackets
First part of number below corresponds to diagram number above:
Current parts — order these
| Ref | Part # | Description |
|---|---|---|
| S1–S2 | 041-0136 | Safety sensor eye kit — sending and receiving eyes, supplied as a matched pair |
| S3–S4 | 041A5281-1 | Sensor extension brackets |
| — | 041-0155-000 | Safety sensor brackets, 2021 to present |
| — | 041B0873 | Sunblocker bracket — stops sunlight false-tripping the eye |
| — | Sensor Guards | Protective guards, sensors not included |
| — | 041B4494-1 | 2 conductor bell wire, 26 ft |
Superseded part numbers
The current eyes and brackets replace every earlier version, so there is no need to match your old part number — order the current part.
| Old Part # | Order Instead | Notes |
|---|---|---|
| 41A5034 | 041-0136 | Eye kit used 1997 onward, now superseded |
| 12B484 | 041A5281-1 | Square holed mounting bracket, discontinued |
| 12B485 | 041A5281-1 | Slotted mounting bracket, discontinued |
| 041A5266-1 | 041-0155-000 | Sensor mounting bracket, no longer available |
5. Remotes, Wall Controls and Door Hardware
First part of number below corresponds to diagram number above:
| Ref | Part # | Description |
|---|---|---|
| 01–02 | 893MAX | 3 button visor remote — universal replacement for all older remotes |
| 03 | 10A20 | 3V coin battery for the remote |
| 05 | 10A14 | 12V battery — 61LM series remotes |
| 06 | 041B4494-1 | 2 conductor bell wire, 26 ft |
| 07 | 041A4353 | Header bracket, 1993 to current |
| 08 | 041A5047 | Door bracket |
| 09 | 041A2828 | Manual release rope and handle assembly |
| 10 | 29C128 | Remote visor clip |
| 11 | 29B137 | Remote visor clip — 700 and 800 series remotes |
| 12 | 041A4166 | Lighted pushbutton, two wire |
| 13–15 | 041C0494-2 | Multi-function door control panel — the replacement on pre-1998 openers |
| 13–15 | 889LM | MyQ control panel — the replacement on 1998 and newer openers |
| — | 041A4202-6B | Wall control panel, two wire |
| — | 041A2770-17 | Installation hardware kit — bolts, staples, grease, release cord |
| — | 041A3504 | Antenna extender kit |
| — | 041A3504-1 | Antenna extender kit with adapter |
| — | L6950 | Multi purpose spray lube, green |
| — | L6960 | Multi purpose spray lube, blue |
Remote controls
The original remotes for these openers are discontinued. The 893MAX is the universal replacement and works with all the older LiftMaster, Chamberlain and Craftsman openers. It covers 371LM, 971LM, 973LM and 893LM, and is the listed substitute for 81LM, 83LM, 63LM, 753CB, 850CB, 853CB, 953CB, 953EV and Craftsman 53680, 53859 and 53879. Browse all LiftMaster remote controls.
Wall controls — superseded part numbers
| Old Part # | Order Instead | Notes |
|---|---|---|
| 041C0494-1 | 041C0494-2 | Multi-function door control panel, superseded |
| 41C494 | 041C0494-2 | Soft glow wall control panel, no longer available |
| 98LM | 889LM | Motion detecting control panel, discontinued, 1998 and newer |
| 398LM | 889LM | Control panel, discontinued, 1998 and newer |
| 888LM | 889LM | Control panel, discontinued, 1998 and newer |
More LiftMaster Parts
All chain drive rail parts · Chain and master links · All LiftMaster opener parts · LiftMaster remote controls