In a forage harvester having a cutter for chopping gathered crop material, a unit is arranged downstream of the cutter, the unit including an accelerator arranged in the path of crop flow for propelling the crop towards a discharge spout, and a crop processor for cracking kernels which is selectively movable into and out of the crop flow path at a location between the cutter and the accelerator. The accelerator comprises a rotor and housing which are together movable towards the cutter when the crop processor is withdrawn from the crop flow path.