A system for the mutual adjustment of two drive shafts connected by means of a cardanic shaft is described, the first shaft being actuated by a machine by means of a power take-off being connected to a cardanic shaft, said cardanic shaft being connected to a second shaft being a power take-off of a miter gear box of a crusher/tiller, the miter gear box actuating at least one machine tool. According to the invention the miter gear box is connected to the chassis of the crusher/tiller by means of two small arms in order to allow both a rotation about one axis and a transverse movement controlled by a tilting and rotation sensor.