he article considers forced nonlinear oscillations of three disks on a light elastic shaft with a bunch of nonlinear characteristics. The equations of the first approximation are constructed by the asymptotic method for the amplitude and phase of the two-frequency oscillation mode. A series of numerical examples is processed for the case of stationary and non-stationary conditions, and the amplitude-frequency covers are drawn for both stationary and non-stationary two-frequency modes of shaft oscillation for the case of changing the frequencies of forced moments.