Cracks in rotors are not only important from a practical and economic point of view, but they also show interesting dynamics. This article shows the effect of the crack model on the response of the Jeffcott rotor model with the offset disc and bearing support flexibility using the ANSYS harmonic balance approach. Dynamic coefficients of stiffness and damping of plain bearings in the form of matrices were found using MATLAB. An analysis of the response to the imbalance was carried out with a change in imbalance mass, and a maximum rotor response was then found for each imbalance mass for the case when the depth of the crack was 10 mm. The main reason for analyzing the dynamics of the fracture rotor is to help engineers find a good design, also the possibility of finding the critical speed, the response to imbalance and the stability of the system.