A trailer suitable for hauling farm implements along highways is expandable from a contracted, empty position to an expanded loaded position. In expanded position, the rear support wheels are outside normal highway width limits. The trailer frame has a forward section, supported at its rear with centrally located ground wheels, and a pair of rear sections each supported by an outside wheel. Each rear section has a pair of transverse telescopic beams. One set of vertical hydraulic or pneumatic cylinders lifts the forward central wheels and the rear sections off the ground. A set of transverse cylinders moves the outside wheels to expanded position. Each outer rear beam section has a loading ramp hinged thereto about a transverse axle and a wheel support hinged thereto.

A self-propelled high clearance machine for agricultural uses such as a sprayer having laterally adjustable drop axle wheel support means that may be positioned in a number of different settings to adapt the sprayer for universal use in the spraying of different crops that have been planted with variations in the width or spacing between their rows.

Trailer having a main frame with a horizontally extending deck and a pair of longitudinally extending rails spaced a predetermined distance apart for receiving flanged wheels of railroad equipment, and a laterally extensible rear subframe assembly connected to the main frame for movement between different widths for different loads. The subframe assembly has a pair of longitudinally extending rail members which can be aligned with the rails on the main frame to form an extension of those rails.