Abstract: A regulating device is disclosed for a working machine including at least four rubber wheels and a railway wheel unit in the area of a forward and rearward end, respectively, of the working machine, which each include at least two railway wheels and of which at least one can be raised and lowered by way of at least one power generating device. The regulating device includes a position regulating device by which the power generating device, in a driving position, is automatically controllable to maintain the railway wheels on a predetermined perpendicular distance from an arbitrary reference point on the chassis of the working machine. A railway wheel device, a working machine and a method for regulating the railway wheel unit are also disclosed.