Abstract: A flail shredder having a drive shaft mounted for rotation about an upwardly extended longitudinal axis for earth traversing movement transversely of the axis and for adjustable movement transversely of the line of movement; a power drive connected to the shaft; a flail assembly mounted on the lower end of the shaft; a stop limiting the adjustable movement in one direction; a resilient member urging the shaft toward the stop; and a guide wheel mounted concentrically with the shaft for independent rotation, the wheel being disposed for rolling engagement of obstructions so as to urge the shaft away from the stop.