A rear wheel drive assist for a wheel tractor scraper, the wheel tractor scraper having a tractor portion with a power source operatively connected to the front driven wheels, and a rear, scraper portion having a bowl, work tool, and first and second rear wheels, the rear wheel drive assist includes a work tool pump fluidly connected to a work tool motor to drive the work tool, fluid operated drive motors operatively connected to the rear wheels, and a diverter valve selectively movable between a first position that delivers fluid flow from the pump to the work tool motor, and a second position that delivers fluid flow from the work tool pump to the rear wheel drive motors.