<p>The tooth load in heavy-duty wind turbine gearboxes is significantly affected by the structural deformations of the planetary gear train (PGT) with the interference fit. In this study, a dynamic modeling method for gear meshes is proposed considering the comprehensive structure flexibility and dynamic tooth contact. The condensation theory of finite elements is utilized to establish the ring gear and carrier, developing correlations between the point of action and elastic support. Furthermore, the dynamic mesh deformation considering the influences of pin-axis deviation caused by the interference fit is deduced. Finally, a dynamic model of PGT with flexible pins is established and subsequently verified. The pin-axis deviation resulting from the interference fit and its impact on tooth loads and system vibrations is investigated. The results indicate that the main cause of unbalanced tooth loads is the asymmetric deformation of the carrier pin. Additionally, in the resonance region, this phenomenon will worsen, and there is a significant difference between the dynamic meshing stiffness and the quasi-static meshing stiffness. As the interference-fit magnitude increases, the pin-axis deviation amplifies, leading to a more severe tooth load imbalance.</p>