The aim of this master’s thesis was to analyze the dynamic behavior of a model of gearbox for e-drive light vehicles to the dynamic excitation provided by the unavoidable imperfection meshing of the gears that are inside. In particular, the work of this thesis was focused on one of the most important phenomena counted into NVH world: ‘’Gear Whine’’, or rather the characteristic tonal noise from the gearbox at the gear mesh frequency and its harmonics. It’s a vibrational excitation caused by the Transmission Error (TE) since it is considered the main source of noise coming from the gears meshing.