A suspension system for agricultural implements having at least one floating head using a four-bar linkage, and permitting the floating head to accommodate variations in ground surface elevation in a lateral or transverse direction. By permitting the floating head to float, a more consistent cutting height is realized when ground surface elevation varies in a transverse direction. A main frame is provided to which the ground engaging wheels are attached. A sub-frame is connected to the main frame via the four-bar linkage. The sub-frame is pivotally attached to the arms of the four-bar linkage by spherical and cylindrical bearings. The lower linkage arms of the four-bar linkage are maintained in compression while the upper linkage arms are maintained in tension. Due to the compression and tension in the linkage arms, the floating head will self-level in the transverse direction when raised, yet allow the header to float during operation.