Abstract: The present invention provides an under-frame lift axle assembly for a vehicle, particularly an off-road vehicle, which includes a suspension lower link element having one end mounted to the frame of said vehicle by a first pivotal joint, an axle assembly, adapted to mount a wheel and tire thereon, distal to said first pivotal joint, and a second pivotal joint, permitting articulation of the lower link, medially located on said suspension lower link element, a retractable suspension assembly, such as an air bag suspension assembly, mounted between said frame and the suspension lower link element intermediate to said first pivotable joint and said second pivotal joint, an upper link member to limit or prevent articulation of said suspension lower link element at said medial second pivotal joint when said suspension assembly is deployed to bear a share of the vehicle weight, a lift device , such as a second air bag assembly or the like, to lift said suspension link element and said axle assembly away from groun