An agricultural tool unit includes a tool configured to engage the ground and a mounting device. The mounting device supports the tool and presents a device opening configured to receive the frame member. The mounting device includes driving and driven cam elements, with the driven cam element defining at least part of the device opening. The mounting device further includes a cam element shifter operable to selectively impart relative shifting of the cam elements in a first direction. The cam elements present respective cam surfaces that are complementally shaped and slidably engaged with one another to define a cam interface, with the cam interface extending transversely to the first direction such that the driven cam element is moved in a transverse second direction when the cam elements are relatively shifted by the cam element shifter. The driven cam element is configured to adjustably exert a force against the frame member when moving in the second direction.