Abstract: A crawler tractor is disclosed with a counterweight assembly which affords optimum weight distribution and traction for operation on steep slopes and grades. The assembly includes a counterweight body having a shank which is carried by a housing mounted by a support arm weldment on the rear end of the tractor. The shank is releasably engaged with the housing. Hydraulic actuators are provided to move the counterweight to a lowered position for backing the tractor uphill, and for raising the counterweight for dozing in a downhill direction. One embodiment provides for selective fore and aft positioning of the counterweight relative to the tractor in accordance with operating conditions.