Chamberlain WD900D & HD900D Belt Drive Parts
Chamberlain WD900D and HD900D Replacement Parts
These are DC belt drive openers with battery backup, running on a square rail. Most of the mechanical and power parts are still available — motor, transformer, harness, battery and end panel — but the logic boards are not. Read the note below before starting a repair.
- WD900D
- HD900D
Logic boards for these models are discontinued. Both versions — the 315 MHz 041DB002-2 and the 390 MHz 41DB002-2-390 — are no longer manufactured and there is no replacement. If several remotes have stopped working at once, or the opener is dead with power reaching the transformer, that is usually the board. Call (866) 965-5599 before spending anything else — we will tell you honestly whether the repair is still worth doing, and you can see current replacement openers if it is not.
Beeping, running slowly, or dead during a power cut? That is almost always just the backup battery — the 41A6357-1 12V battery, also sold as the 485LM. It is a consumable and lasts a few years. The opener runs normally on mains with a dead battery; it just will not work during an outage.
1. Garage Door Opener Repair Parts
First part of number below corresponds to diagram number above:
| Ref | Part Number | Description |
|---|---|---|
| 01 | 041C0076 | Belt cap retainer and cog |
| 02 | 041B4245-1 | Line cord, 6 ft |
| 03 | 41B4375-3 | Terminal block with screws — no longer available |
| 04 | 041A6281 | Wire harness kit |
| 05 | 041D0794 | Motor with positioning sensor |
| 06 | 041DB002-2 | Receiver logic assembly, 315 MHz — no longer available |
| 06 | 41DB002-2-390 | Alternate frequency board, 390 MHz — no longer available |
| 07 | 041A6231 | End panel with battery door and screw |
| 08 | 041C0190 | Transformer and harness |
| 09 | 41D504-6 | Cover for HD900D — no longer available |
| 10 | K108D0079M | Light lens |
| 11 | 175B88 | Light socket |
| 12 | 41A6357-1 | Battery, 12V — also sold as 485LM |
| — | 041A2770-17 | Installation hardware kit |
The 041D0794 motor comes with its positioning sensor, so you do not need to source that separately. If the door reverses at the wrong point, the positioning sensor is the usual cause and it arrives with the motor. Three parts on this diagram are discontinued: the terminal block, the HD900D cover and both logic boards.
2. Belt and Square Rail
| 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 |
The belt is sized to your door height, not your rail — measure the door opening. A belt rarely fails on its own: check the idler pulley, trolley, tensioner and wear pads while the rail is apart. See all Chamberlain belt and rail parts.
3. Safety Sensors and Brackets
| 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. If your brackets are bent or missing too, the 041-0365-000 includes eyes and brackets together.
4. Door Hardware and Remotes
| 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 |
These are square rail openers, so they take the 041A5047-3 header bracket — the standard header brackets will not fit. Browse all Chamberlain remote controls.
More Chamberlain Parts
All Chamberlain opener parts · Belt drive belts and rail parts · Chamberlain remote controls