Abstract: A trailer combined with a movable wheel assembly. The trailer comprises a front portion and a load carrying bed portion. The front portion is combined with the load carrying bed portion at a pivot point so that the front portion and load carrying bed portion can pivot relative to each other. A rack and pinion means allows selective movement of the wheel assembly relative to the trailer. The rack is combined with the load carrying bed portion of the trailer, and the pinion is combined with the movable wheel assembly. A power assist means, such as a hydraulic motor, is combined with the movable wheel assembly and is adapted to rotate the pinion. Activation of the power assist means rotates the pinion and moves the wheel assembly in a first direction along the rack towards the front of the load carrying bed or in a second direction along the rack towards the rear of the load carrying bed.