This study investigates the dynamic response of a locomotive drive system experiencing wheel/rail saturation adhesion. A dynamic locomotive model is created and then integrated with electromechanical and control systems to simulate the vibration in the component parts of the drive system. The model is used to investigate the drive system’s sensitivity to resonance effects. The obtained results show that the wheel/rail stick-slip state can experience both longitudinal vibrations and self-excited vibrations in the drive system. Different parts of the drive system are excited by the two types of vibrations; however, in both cases the main frequencies are multiples of the natural frequency vibration of the drive system. It is necessary to select an appropriate value for the motor suspension rubber stiffness if structural resonances of the drive system under wheel/rail saturated adhesion are to be avoided.