Abstract: A motion platform assembly having at least three degrees of freedom for providing simulated motion in a flight or vehicle simulator. The motion platform assembly includes a base frame, mounting pedestal and a stabilized platform. The simulator is powered by actuators that independently effect movement with respect to the base frame by extending to increase and decrease a length. Stabilizers stabilize the motion platform assembly by restricting movement of the stabilized platform while only permitting vertical translation of the stabilized platform relative to the mounting pedestal in both directions. In one embodiment, the stabilizers are unpowered linear bearings extendable to increase and decrease a length thereof between the mounting pedestal and the stabilized platform. The linear bearings resist the shear forces acting upon the stabilized platform when the stabilized platform is vertically extended from the mounting pedestal.