The hinged part of the vehicle consists of the frame, axle with wheels and the suspension. On passenger vehicles the body of the car takes on the role of the frame. Out of this reason the body is additionally reinforced. In some trucks, the role of the frame is taken on by a complex part which consists of the engine housing, the clutch, the gear shift and the propulsion bridge. All circuits, devices and aggregates are connected to the hinged part of the vehicle, which enables the vehicle to act as a whole. The hinged part of the vehicle is being stressed by all the possible forces that can interact with the vehicle itself. Therefore, in this case study the following terms will be explained in detail: the hinged part of the vehicle, shock absorbers, the suspension and the vehicle management system.