The Dutton-Lainson TW4000 StrongArm is a 12V DC boat and vehicle-trailer pulling winch with a 1,500 lb rating, a mechanical holding brake and a 2-inch × 20-foot polyester strap. Its power-in and controlled freewheel design uses a clutch knob rather than the TW9000's lever. The repair list below applies to TW4000 units stamped 2014 or later.
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Original winch exploded drawing
The manufacturer document includes the complete assembly illustration and repair-parts key. Use the matching model and production date when choosing an individual replacement.
Open the original PDF on your phone to zoom in on the internal gears and part labels.
TW4000 2014-and-later parts by factory callout
Manufacturer part numbers are listed for identification. Individual internal repair parts are not implied to be sold separately by NewRVParts.
| Callout | Dutton-Lainson part number | Component |
|---|---|---|
| C | 304967 | Drive shaft assembly |
| D | 204703 | 56-tooth gear |
| J | 406155 | Winch base |
| R | 206228 | Motor pinion gear |
| S | 304698 | Roller clutch assembly |
| T | 404559 | Reel shaft |
| X | 304858 | Reel assembly |
| Z | 306224 | 12V electric motor for TW4000 |
| AF | 5242607 | 2-inch × 20-foot winch strap |
| AJ | 5703194 | Thrust-bearing replacement kit |
| AK | 306102 | 120-tooth gear assembly |
| AM | 306100 | Clutch gear assembly |
| AR | 206243 | Clutch-control knob |
| AT | 306225 | Electrical wiring harness |
| AV | 206249 | Toggle switch |
| AW | 404831 | Toggle-switch guard |
Identify the electrical and clutch components
TW4000 loads the strap under electric power and releases it through a controlled freewheel clutch. For manual operation during loss of power, Dutton-Lainson specifies a 5/8-inch socket and ratchet with the clutch engaged; remove the socket before using the motor. The manufacturer recommends no more than three minutes of continuous electric running before cooling. The strap winds over the top of the drum.