An agricultural harvesting machine including a chassis, and a threshing section carried by the chassis. The threshing section includes a rotor, a plurality of frame assemblies adjustably positioned proximate to the rotor, a plurality of concaves and an adjustment mechanism. Each concave is carried by a corresponding frame assembly. The adjustment mechanism is coupled to the frame assemblies. The plurality of frame assemblies are X frame assemblies, with X being 2 or larger. The adjustment mechanism has at least one actuator, with there being Y actuators, with Y being 1 or larger. The adjustment mechanism is configured to adjust each of the X frame assemblies to different positions with Y actuators, where Y is less than X.
