This thesis builds on a previous work in which an MSC Adams model of a reduction gearbox for a turboprop engine developed by Avio Aero was created using the Gear AT tool, with all components represented as flexible bodies. While the previous study investigated the slow-roll regime, the present work focuses on the behavior of the model at higher rotational speeds in order to assess the performance of MSC Adams in high-speed dynamic simulations involving flexible-body interactions and high-frequency phenomena. The study investigates the influence of initial conditions, speed-sweep direction, simulation-time partitioning, and selected model parameters on the numerical response. Two speed-sweep approaches are compared to evaluate the effects of transient behavior and numerical artifacts appearing as vertical banding in the Campbell diagrams.