The traction motor-reducer units are an independent and complex system, since the processes occurring in it have a different physical nature. Therefore, to assess the technical condition of the mechanical and electrical elements of electromechanical equipment, as well as to control its technical condition, it is advisable to carry out comprehensive tests before putting the equipment into operation. The main disadvantage of the existing methods for separate testing of mechanical and electromechanical units is that they do not take into account the interconnection and interdependence of the overall operation of the traction drive elements, in particular the motor and gearbox, the method for determining the influence of the mutual operation of which is proposed in this Thesis research.