Abstract: The invention is a tandem wheel suspension which may be utilized on a vehicle to replace a single axle suspension and increase vehicle performance. The single axle suspension can be incorporated into the tandem wheel suspension. Claims are made to the tandem wheel suspension and to a method of replacing a single axle suspension with such tandem wheel suspension.

Abstract: A motorized vehicle having both steerable front wheels and driven steerable rear wheels. The front wheel suspension is such that a greater degree of turn is possible. The orientation of the rear wheels relative to the line of travel of the vehicle may be controlled by the operator or alternatively may be automatically oriented to properly track the front wheels. A zero center spool valve is mounted such that proper tracking is assured, an additional change in the front wheel angularity results in the appropriate and necessary change in their rear wheel angularity. The valve body is mounted to change its position in response to orientation of the rear wheels and the spool position is directly related to the orientation of the rear wheels such that appropriate relative positioning of the front wheels centers the spool terminating fluid flow to front wheel orientation controlling cylinders.