Gearboxes are an integral part of the various devices, machines, cars etc. employed in a lot of branches of industry. It has to meet the certainty of individual components and, last but not least, reliability and durability. The paper focuses on the behaviour of these components following the noise under load level. Three experiments on different devices were conducted. The first test was on running conditions at device stand, the second test at Powertrain stand at Laboratories of Vehicles and Motors Department, TU of Liberec. The third one was performed in real traffic. The methods for following vibration diagnosis of cars gearbox are a modern instrument for controlling quality of assembly and manufacture of cars gearbox parts. Moreover, it has a big importance in solving the problems of noise and vibration of automobile gearbox.
