A diagonal brace apparatus for an implement frame includes a bias element connected to a front location on a front portion of the implement frame and connected to a rear location on a rear portion of the implement frame laterally offset from the front location. The bias element is operative to exert a bias force resisting rearward movement of an outer end of the implement frame with respect to an inner end of the implement frame. Conveniently the bias element is provided by a hydraulic cylinder which exerts a bias force and can extend to allow the frame to flex to reduce shock loading on the implement when excessive forces are exerted on the frame.
