The Impact of Manufacturing Variability on NVH in Gears and Transmissions

Manufacturing variability has a measurable impact on the NVH behavior of gear drives. Small deviations in tooth geometry or surface quality can increase transmission error. These effects become more pronounced in electric powertrains due to the lack of masking noise. Housing stiffness variations further shape how gear-mesh excitations are radiated as airborne sound. This review examines how common gear and housing tolerances influence NVH performance and summarizes recent advances in stochastic analysis, robust design, and measurement-driven modeling. The results show that unit-to-unit differences in gear quality and housing dynamics can shift radiated noise by several decibels. Integrating real manufacturing data, statistical tolerance assessment, and coupled structural–acoustic simulations provides a practical approach to achieving consistently quiet powertrains in series production.