A concave adjustment device for an agricultural harvester includes a rotor having a longitudinal axis, a concave encircling at least a portion of the rotor, and a linkage connected to the concave for moving the concave with respect to the rotor. The linkage includes a first link, a second link and the concave. The first link has a first portion connected to a device for moving the linkage and a second portion connected to one side of the concave. The second link has a first portion pivotably connected to an opposing side of the concave and a second portion pivotably connected to a fixed point on the harvester. The device for moving the linkage is configured to translate the first link, which causes rotation of the second link and movement of the concave with respect to the rotor.