Abstract: A shift travel device, exemplified by a vertical lift arm device, is described which provides for free rotation of its cylinder and arm about its shaft and free travel along the shaft without transfer of twist imposed by the arm and load to its shaft, constant sealing of operating air pressure within the cylinder during operation and load changes, and minimum friction during rotation when the cylinder and arm are in the extreme raised or lowered positions. The device includes unique self-aligning spherical bearings at the ends of the cylinder. The device is useful is a wide variety of environments, including those which are unusually dirty or clean.