Abstract: A suspension assembly for mounting a wheel assembly to any wheel position of a vehicle, the suspension assembly being pneumatically controlled to adjust both the ground clearance of the vehicle and its wheel-track width, the suspension assembly also being mountable at any wheel position whether the wheel at that position is to be steerable or nonsteerable. The suspension system includes upper and lower control arms connected between a frame attachable to the vehicle and a kingpin assembly to provide a parallelogram linkage. It also includes at least one pneumatically actuated linear actuator to control the angular disposition of the lower control arm with respect to the frame and thereby control the ground clearance and wheel-track width of the vehicle. The parallelogram geometry provides the upper and lower control arms with at least 120 degrees of angular travel.