Sprayer with hydraulically adjustable wheel spacing

A self-propelled chemical applicator with adjustable rear wheel tread includes two rear fore-and-aft spaced cross tubes which are cantilevered from the main frame. A pair of roller mechanisms are supported between the tubes on opposite sides of the centerline of the vehicle. Each mechanism includes a roller frame supporting eight rollers, two transversely spaced on each of the upper and lower sides of each tube. The roller frames, contained between and rollable along the tubes, are connected to the upper ends of corresponding drop assemblies which mount hydraulically driven wheels. A transversely extending hydraulic cylinder is connected between each roller frame and the main frame to roll the drop assembly in or out to change wheel spacing. Each drop assembly is releasibly clamped in position by a simple mechanism which includes a fore-and-aft extending bolt which pulls the spaced cross tubes towards each other to clamp the roller frame tightly between the tubes.