A tool carrier has a carrier frame and ground tools, and a front end of thecarrier frame isconnected to a wheel supported tool bar frame. A crank arm is pivotallyattached to thetool bar frame about a crank axis oriented horizontally and perpendicular toan operatingdirection. A front end of the carrier frame is pivotally attached to the crankarm about acarrier axis parallel to the crank axis, and a hydraulic cylinder attachedbetween the crankarm and the tool bar moves the tool carrier from an upward transportorientation to arearward extending horizontal operating orientation, and maintains the toolcarrierhorizontal while moving it from a headland position above the ground to aworkingposition where the tools penetrate the ground. When the tool carrier assemblyis in theworking position, the hydraulic cylinder exerts a downward bias force on thetool carrier.