A direct OEM-grade replacement inner slide-out arm for Lippert rack-and-pinion slide systems. This outboard arm ships with the gear rack already installed and a durable black powder coat finish applied, so you spend less time on prep and more time getting your rig back on the road.
Lippert's rack-and-pinion slide-out system is one of the most common mechanisms found across travel trailers, fifth wheels, and Class A motorhomes. When the inner arm bends, cracks, or loses its gear rack engagement, the entire slide becomes unreliable -- or won't move at all. Replacing with the correct factory-spec arm restores proper alignment, full extension, and the load-bearing capacity the system was designed around.
Part number 143707 is specifically the outboard inner arm in the 2.5 x 2.5 inch square tubing size, corresponding to Lippert figures 8.1 and 8.2 in their slide-out arm reference diagrams. At 72 inches in length, this arm fits a wide range of mid- to full-size slide-out rooms. Always verify your existing arm length and tube cross-section before ordering.
Rack comes mounted and aligned from the factory -- no separate rack purchase or time-consuming installation required.
Corrosion-resistant finish holds up to road grime, moisture, and the repetitive motion stress of regular slide cycling.
Manufactured to the same specification as the original arm installed at the factory, ensuring proper mesh with existing pinion gears and guides.
Heavy-duty square steel construction maintains rigidity under slide room load -- critical for rooms carrying furniture, appliances, or flooring weight.
In a Lippert rack-and-pinion slide system, the slide room rides on a pair of arms -- an inboard arm (closest to the coach interior) and an outboard arm (positioned toward the exterior wall). Each arm has an inner tube that slides within an outer tube, extending and retracting as the motor drives the pinion gear along the rack. The inner outboard arm (this part) is the telescoping inner section on the exterior side of the slide room.
Replacing only the damaged inner arm -- rather than the full assembly -- is the correct approach when the outer tube and mounting hardware are still in serviceable condition.
This arm is used on Lippert rack-and-pinion slide-out systems installed across many RV brands that source components from Lippert (formerly Lippert Components / LCI). Common applications include:
Swapping an inner slide-out arm is a moderately involved procedure. The slide room typically must be in the extended position for access, and the arm must be properly aligned with the pinion gear before the system is cycled. A second person or a slide room support stand is strongly recommended during the swap to prevent the room from shifting unexpectedly.