These are Whisper Drive square rail belt openers. Their belt, rail and trolley are square rail specific and will not interchange with the T-rail parts used on most belt drives. This parts list covers all variants:
Ordering a belt? These openers take the 041A5250 square rail belt, sized to your door height — 7, 8 or 10 ft. Measure the door opening, not the rail. Note that 41AB050-2M is the logic board, not a belt — the two are often confused.

First part of number below corresponds to diagram number above:
| Ref | Part Number | Description |
|---|---|---|
| 01 | 041A4371 | Belt cap retainer |
| 02 | 041A4885-5 | Gear and sprocket assembly |
| 03 | 041A2817 | Gear kit |
| 04 | 041B4245-1 | Line cord, 6 ft |
| 05 | 041A5484 | End panel with all labels |
| 06 | 041C0279 | Light socket |
| 07 | K108D0079M | Light lens |
| 08 | K030B0532-1 | Capacitor |
| 09 | K012A0373 | Capacitor bracket |
| 11 | 41C4842 | Universal replacement motor and bracket assembly |
| 11–12 | 41A5525-4 | Cover — no longer available |
| 13 | 041A2818 | Limit switch drive and retainer |
| 13 | 041D3452 | Limit switch assembly |
| 15 | 041A2822-1 | Interrupter cup |
| 16 | 041C4398A | RPM sensor assembly |
| 17 | 041AB050-2M | Receiver logic board assembly — current replacement |
| 17 | 41A5483-4B | Receiver logic board assembly — no longer available |
| 18 | 041C5499 | High voltage wire harness |
| 18a | 041C5500 | Low voltage wire harness |
| 19 | 041D0180-1 | End panel |
| — | 041A2770-17 | Installation hardware kit |
Logic board — order the 041AB050-2M. The original 41A5483-4B is discontinued and the 041AB050-2M replaces it. You may see this board described elsewhere as a "Whisper Drive belt" — it is not a belt, it is the circuit board. Read the number printed on the board you are removing to confirm, and call (866) 965-5599 if it is neither. The cover (41A5525-4) is discontinued with no replacement.
If the motor runs and the door does not move, that is the gear and sprocket assembly at ref 02 — the nylon gear strips. Grease the worm before fitting the new one; running it dry is what strips the next.
| Ref | Part Number | Description |
|---|---|---|
| — | 041A5250 | Full belt assembly — 7 ft door |
| — | 041A5250-1 | Full belt assembly — 8 ft door |
| — | 041A5250-2 | Full belt assembly — 10 ft door |
| — | 041A5665 | Square rail assembly |
| — | 041C5141-2 | Complete trolley assembly, square rail |
| — | 041D0598-1 | U bracket, square rail |
| — | K144C0054M | Belt idler pulley |
| — | 041B4103 | Belt tensioner assembly |
| — | 041A7276 | Wear pads |
| — | 004A1008 | Master link kit |
A belt rarely fails on its own. Check the idler pulley, trolley, tensioner and wear pads while the rail is apart — worn pads let the trolley rock in the rail and will chew through a new belt in months. See all Chamberlain belt and rail parts.
| Ref | Part Number | Description |
|---|---|---|
| — | 041-0136 | Safety sensor eye kit — replaces 41A5034 |
| — | 041-0155-000 | Safety sensor brackets, 2021 to present |
| — | 041-0365-000 | Sensor eyes and brackets — the complete set |
| — | 041B0873 | Sunblocker bracket — stops sunlight false-tripping the eye |
| — | 041B4494-1 | 2 conductor bell wire, 26 ft |
The current 041-0136 eye kit replaces the older 41A5034 and fits Chamberlain and LiftMaster openers alike — both brands are built by the same manufacturer. If your brackets are bent or missing too, the 041-0365-000 includes eyes and brackets together.
| Ref | Part Number | Description |
|---|---|---|
| — | 041B0035B | Curved door arm |
| — | 4178B0034B | Straight door arm section |
| — | 041A8094 | Door arm kit — curved and straight sections together |
| — | 041A5047-1 | Door bracket with clevis pin and fastener |
| — | 041A5047-3 | Header bracket — square rail |
| — | 041A2828 | Emergency release rope and handle |
| — | 893MAX | 3 button remote control — universal replacement |
| — | 041C0494-2 | Multi-function door control panel |
These are square rail openers, so they take the 041A5047-3 header bracket — the standard header brackets will not fit. The 893MAX replaces every older Chamberlain, LiftMaster and Craftsman remote. Browse all Chamberlain remote controls.
All Chamberlain opener parts · Belt drive belts and rail parts · Chamberlain remote controls