Chamberlain CSO Replacement Parts
Chamberlain CSO Replacement Parts
The CSO is a light commercial trolley operator rather than a standard residential opener. It shares its drivetrain with the LiftMaster ATS range — same gear and sprocket, same pulley, same motor and bracket assembly — so parts from that family fit.
Motor runs but the door does not move? That is the 041C4470 gear and sprocket assembly at ref 03 — the nylon gear strips. Grease the worm before fitting the new one; running it dry is what strips the next. The 041A2817 drive and worm gear kit is the alternative if only the gear itself has gone.
1. Garage Door Opener Repair Parts
First part of number below corresponds to diagram number above:
| Ref | Part Number | Description |
|---|---|---|
| 01 | 41C5069 | Chassis support bracket assembly |
| 02 | K144B0018 | Pulley |
| 03 | 041C4470 | Gear and sprocket assembly |
| 04 | 041A2817 | Drive and worm gear kit with grease and roll pins |
| 06 | 041C0279 | Light socket |
| 07 | K030B0532-1 | Capacitor |
| 08 | K10-10351 | Capacitor bracket and clamp |
| 09 | 041A3150 | Terminal block with screws |
| 10 | 041D4509 | Motor and bracket assembly |
| 11 | 41A4936 | Cover — no longer available |
| 13 | 041D3452 | Limit switch assembly |
| 14 | 041C4398A | RPM sensor assembly |
| 15 | 041C4246 | Wire harness |
| 16 | 041A2817 | Gear kit including bearings |
| — | 041A2770-17 | Installation hardware kit |
The cover is no longer available. The ref 11 cover (41A4936) is discontinued with no replacement. Every other part on this diagram is available — unusual for an operator of this age, and worth knowing before you write one off. The 041A2817 gear kit is called out twice, at refs 04 and 16 — it is the same kit either way.
Because the CSO shares the ATS drivetrain, if a part you need is not listed here it is worth checking the LiftMaster ATS parts page — the gear, pulley and motor are common to both.
2. 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 — 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.
3. Chain and Rail
| Ref | Part Number | Description |
|---|---|---|
| — | 004A1008 | Master link kit |
| — | 041A5807 | Chain and cable — 7 ft door |
| — | K144C0056 | Cable idler pulley |
| — | 183A163 | Wear pads |
The chain is sized to your door height — measure the door opening, not the rail. A slack chain can usually be re-tensioned rather than replaced. Browse all chain and master links.
4. Door Hardware and Remotes
| Ref | Part Number | Description |
|---|---|---|
| — | 041B0035B | Curved door arm |
| — | 4178B0034B | Straight door arm section |
| — | 041A5047-1 | Door bracket with clevis pin and fastener |
| — | 041A2828 | Emergency release rope and handle |
| — | 893MAX | 3 button remote control — universal replacement |
| — | 041C0494-2 | Multi-function door control panel |
The 893MAX replaces every older Chamberlain, LiftMaster and Craftsman remote. Browse all Chamberlain remote controls.
More Parts
All Chamberlain opener parts · LiftMaster ATS parts · Chain and master links