A tool carrier has a carrier frame and ground tools, and a front end of the carrier frame is connected to a wheel supported tool bar frame. A crank arm is pivotally attached to the tool bar frame about a crank axis oriented horizontally and perpendicular to an operating direction. A front end of the carrier frame is pivotally attached to the crank arm about a carrier axis parallel to the crank axis, and a hydraulic cylinder attached between the crank arm and the tool bar moves the tool carrier from an upward transport orientation to a rearward extending horizontal operating orientation, and maintains the tool carrier horizontal while moving it from a headland position above the ground to a working position where the tools penetrate the ground. When the tool carrier assembly is in the working position, the hydraulic cylinder exerts a downward bias force on the tool carrier.
