Abstract: An improved suspension assembly for a seismic exploration vehicle having a substantially rigid main frame supported and moved by track assemblies disposed along opposing sides of the frame. The suspension assembly includes two bogies which engage the inner periphery of a track on one side of the vehicle and each of the two bogies is mounted on one end of a bogie arm that is pivotally connected, at the other end of the bogie arm, to a central portion of a walking beam pivotally connected to the vehicle frame. End portions of the walking beam overlay the distal ends of the bogie arms and air bags are mounted between the distal ends of the bogie arms and the ends of the walking beam to bias the bogie arms in a downward direction.