A worn or broken torsion arm is one of the most common reasons an RV awning refuses to retract cleanly or rolls up unevenly. The Dometic 3310420.017U is an OEM-equivalent, direct-fit replacement for the left-hand torsion arm on A&E 9100 Series awnings. It ships as a complete, pre-wound assembly so you can swap it out in a single service session without sourcing individual spring components.
The torsion arm is the mechanical heart of a cassette-style awning. Its pre-wound coil spring stores energy when the awning is extended and releases that energy to pull the roller tube -- and the fabric -- back into the housing quickly and evenly. When the spring fatigues or the arm cracks, the awning may sag on one side, bind during retraction, or fail to latch securely for travel.
Part number 3310420.017U targets specifically the left-hand side of the 9100 Series mechanism (driver's-side on most coach orientations, but always verify against your awning's label). The black top casting matches the OEM color, and the complete sub-assembly -- spring, rod, pin drive, and top casting -- means no salvaging worn hardware from the old arm.
Factory-wound to OEM tension spec so spring energy is correct from the moment of installation -- no manual winding required.
Includes spring, rod, pin drive, and top casting. All components are new; nothing is reused from the failed arm.
Engineered specifically for the A&E 9100 Series cassette housing. Mounts to existing attachment points without drilling or modification.
Matches the original factory finish for a clean, factory appearance once reinstalled on the coach.
If one torsion arm has fatigued, the other is typically at the same service age and may fail shortly after. Many RV technicians recommend replacing both the left-hand arm (3310420.017U) and the right-hand arm together during the same service visit to ensure balanced spring tension across the full width of the roller tube. Unequal tension can cause the fabric to track off-center or bind in the cassette.
Replacing a torsion arm on a 9100 Series awning is a two-person job. The roller tube is under spring tension even in the stored position, and the arm must be controlled during removal to avoid injury. Basic hand tools are required -- typically a Phillips screwdriver, a 5/16-in. hex driver, and a locking pin or awning rod to hold the tube while transferring the arm.
This part is designed for the Dometic A&E 9100 Series awning family. The 9100 Series has been one of the most widely installed power cassette awnings in the North American RV market and is found on units from a broad range of manufacturers including Forest River, Jayco, Coachmen, Winnebago, and many others. Always cross-reference against the label inside your awning cassette or the awning's original build sheet before ordering.