The wind turbine gearbox is a critical component that plays a vital role in transmitting power from the rotor to the generator. Studies of wind turbine gearboxes are often limited to torsional models and the consideration of rolling element bearings. This work investigates the influence of hydrodynamic bearings in the gearboxes of horizontal-shaft wind turbines. To achieve this, a multi-shaft system model is developed using the finite element method. Shafts are modeled using Timoshenko beam elements with five degrees of freedom per node, connected by helical gears that exhibit time-varying contact stiffness. Hydrodynamic bearings are modeled using Reynolds’ hydrodynamic lubrication theory, and their effects are incorporated into the motion equations through equivalent stiffness and damping coefficients. The gearbox input torque from the rotor is determined by modeling aerodynamics using the blade element momentum (BEM) theory. The response of the gearbox, incorporating the effects of hydrodynamic bearings, is analyzed in frequency domain and compared with that of a system using conventional rolling element bearings. The findings of this study provide valuable insights into the dynamics of wind turbine gearboxes and contribute to the development of advanced algorithms, such as those for condition monitoring based on dynamic response analysis.