Apparatus for recovering grain from a mixture of grain and straw in a combine harvester comprising a conveyor (2) capable of conveying a mixture of grain and straw in a generally horizontal direction to a discharge end; a chute (4) arranged so that said mixture discharged from the conveyor falls onto the chute (4), the chute (4) having a floor that is imperforate to the passage of grain through it and is downwardly inclined and projects beyond said discharge end in the feeding direction of the conveyor (2); a trough (5) covered by a grille provided at or adjacent to the lower end of the chute (4) and adapted so that when the mixture of grain and straw passes down the chute (4), grain is collected by the trough (5) and straw passes over it; and a rotor (7) provided above and adjacent to the rear end of the chute (4) and driven so as to assist the discharge of material from the apparatus, characterised in that the rotor (7) is so that it is adjustable towards and away from the chute (4) to vary the space therebetween for different types of crop and crop conditions. The rotor (7) may be carried between the lower ends of a pair of downwardly extending arms (10) pivotally supported (14) at their upper ends. An adjustment arm (22) may be mounted alongside one arm (10) to pivot with it and to carry drive means comprising an upper input pulley (30) coaxial with the pivot (14) and a lower pulley (33) coaxial with the rotor (7) and releasably connectable to the rotor.