A processing system for a combine harvester having a rotor housing that receives a rotor. A cover directs crop material through the rotor housing. At least one adjustable vane guides the crop material. The vane has a cover-facing proximal edge adjacent the cover and an edge projecting toward the rotor. A leading end of the vane is connected with a first pivot connection and the vane is connected to the cover along its inner edge with a second pivot connection. A line drawn through the pivot connections intersects a plane perpendicular to an axis of the cover and forms an angle with the plane of between 5 and 15 degrees. The vane pivots with respect to the cover about an axis along the line to adjust a tilt angle of the vane. Also, tilting the vane adjusts an angle of the distal edge of the vane relative the plane.
