The steering group of an axle (1) comprising a transversal body (4), rotatably constrained at the respective ends, with wheels (6) and a shackle bar (8) of the wheels (6) arranged parallel to the transversal body (4), envisages a hydraulic jack (11) interposed between the transversal body (4) and the shackle bar (8) of the wheels on the axle; an independent electrohydraulic gearcase (14), activatable on engaging reverse gear and equipped with valve means (37, 38) for feeding hydraulic fluid to the jack (11) so as to realise a corresponding movement of the shackle bar (8) in relation to the value of the steering angle α of the vehicle; first sensor means (23) of angle α and second sensor means to read the angle β of the wheels connected to the electrohydraulic gearcase (14) to command the activation of the valve means (37, 38) of the gearcase (14) in accordance with the rapport between the angles α and β.