Abstract: This study investigates the nonlinear dynamic behavior of a Ravigneaux planetary gear transmission system under crack conditions by establishing a multi-parameter coupled nonlinear dynamic model incorporating crack faults. The model comprehensively accounts for key nonlinear factors, including friction under elastohydrodynamic lubrication, gear backlash, bearing support stiffness, and time-varying mesh stiffness. A time-varying mesh stiffness model with cracks is developed based on the potential energy method. The system’s dynamic equations are solved using the fourth-order Runge-Kutta method. Nonlinear vibration responses under varying crack parameters are characterized through poincare map, FFT spectrum, phase diagrams, time history diagram, bifurcation diagram, and 3D spectrogram. Furthermore, the cell mapping method is introduced to investigate the global dynamic behavior of the system, revealing the coexistence of multiple attractors and their evolution pathways under the influence of multiple parameters. The results indicate that crack faults significantly affect the system's dynamic characteristics, leading to more complex coexistence phenomena and increased instability as crack severity intensifies.