A tillage implement has a main frame provided with power-actuated lift wheels at the rear of the frame and a pair of gauge wheels at the front of the frame. A linkage system connecting the rear wheels with the front wheels transmits the raising and lowering motion of the rear wheels to the front wheels so that the main frame remains level as it is raised and lowered by all of the wheels in unison. However, a coupling that uses an equalizing rocker bar between front and rear linkages of the linkage system permits either of the front wheels to be raised or lowered in a non-corresponding manner relative to the other front wheel as differences in terrain contour are experienced between the two front wheels. During such non-corresponding shifting of the front wheels relative to one another, movement of the two front wheels is in equal amounts but opposite directions to maintain both front wheels engaging the ground at all times and equally sharing the load.
