The Lippert 354179 is a direct-replacement hydraulic cylinder engineered for Lippert 2x2 and 2.5x2.5 through-frame RV slide-out systems. With a 30" stroke, 1.25" bore, and a retracted length of 42.12", this gray-painted steel cylinder restores reliable slide room operation without requiring modifications to your existing hydraulic plumbing or mounting hardware. It supersedes the legacy Lippert part number 133874.
If your RV slide room is sluggish, won't extend or retract fully, or you've identified a leaking or damaged cylinder, the Lippert 354179 is the OEM-spec replacement to restore normal operation. This cylinder is purpose-built for the Lippert hydraulic through-frame slide architecture used in a wide range of Class A motorhomes, fifth wheels, and travel trailers.
The through-frame design routes the cylinder through the RV's structural frame rails, using hydraulic pressure from the coach's central hydraulic power unit (HPU) to drive the slide room in and out. The 354179 uses the same port locations, rod end configuration, and mounting interface as the original production cylinder, making swap-out straightforward for a competent RV technician or experienced DIY owner.
Extends from 42.12" retracted to 72.12" fully extended, matching OEM travel distance for compatible slide rooms.
Standard 1.25" bore diameter delivers consistent hydraulic force output across the full stroke range.
Designed specifically for Lippert 2x2 and 2.5x2.5 through-frame hydraulic slide systems -- no adapter hardware needed.
Direct OEM upgrade. If your rig currently has Lippert part 133874 installed, 354179 is the current replacement part.
Lippert's through-frame hydraulic slide system passes the cylinder body horizontally through the frame of the RV. The rod end connects to the slide room floor structure, while the cap end is anchored to the opposite frame rail. This design keeps the cylinder protected inside the frame and allows the HPU to generate substantial push/pull force across the slide room's full extension.
The 2x2 and 2.5x2.5 designations refer to the tube dimensions of the frame channel through which the cylinder is installed. Confirm your frame tube size before ordering if you are unsure which variant your coach uses. This cylinder is not compatible with rack-and-pinion or electric motor slide systems.
This cylinder is designed to operate with Lippert's standard hydraulic slide power units. It uses conventional hydraulic fittings at the extend and retract ports. Refer to Lippert's hydraulic fluid recommendation documentation to confirm the correct fluid type for your HPU -- using the wrong fluid can damage seals and void the cylinder.
Replacing a through-frame hydraulic cylinder is a moderately involved job. The process generally requires depressurizing and purging the hydraulic system, disconnecting the hydraulic lines at the extend and retract ports, removing the rod-end pin and cap-end mounting hardware, sliding the old cylinder out through the frame, and reversing the process with the new unit. Bleeding air from the system after installation is essential for proper operation.