Abstract: Method and apparatus for relieving friction during adjustment of a sliding tandem trailer's rear wheel assembly with respect to the trailer bed includes a plurality of bed lift devices mounted in the vicinity of the rear wheel assembly. Each of the devices are pivotally mounted to a sliding frame member of the rear wheel assembly for engagement with a respective fixed frame member of the trailer bed. By moving a roller, supported upon a pin which is rotatably mounted to a hydraulically-actuated piston contained within the device, into and out of engagement with the fixed frame member, the relative position of the rear wheel assembly may be suitably adjusted with a minimum of friction to a desired position which properly distributes, relative to the axles of the rear wheel assembly and the axles of the cab, the load upon the trailer bed.