PURPOSE: To improve the self-steering state of the rear axle of an automobile, namely, the running characteristics of a vehicle.

CONSTITUTION: Rear wheels 1 on the rear axle of the automobile are respectively hinged through guide arms 21, which are fixed to a stab shaft, for determining rotating directions thereof to a car body 3 so as to oscillate. In order to influence the self-steering state, namely, to the running characteristics of the vehicle, bearings 5 of both the guide arms 21 on the side of the car body can be slid relatively with the car body 3. The bearings are fixed to a bearing support 6, which is rotatably pivoted on the car body 3, while mutually spaced. A rotary axial line of the bearing support is located inside almost the vertical longitudinal plane of the vehicle at least and can be adjusted between at least almost vertical direction and at least almost horizontal direction by an actuator 7 within this longitudinal plane. Both the bearings 5 are respectively provided in almost the same distance from the rotary axial line 8 of the bearing support 6.