Within the field of automobile NVH（Noise

vibration and harshness） study

the noise and vibration of power train system is always an import aspect

and always is a difficult topic.The reason is

to find out the root cause of the noise and vibration has to be combined with the investigation of the power train related components design features.To eventually resolve the issue the design of related power train components have to be optimized on design.This article will introduce a method to measure and investigate the gear whine noise from a vehicle transmission based on a real case.According to the measurement result

project team flowingly put the effort on the design optimization of the transmission 2nd and 5th gear

and ultimately the transmission gear whine noise which suffers entire vehicle was resolved based on the measurement data.The order analysis and transfer path analysis will be used in this project.With the method and principle introduced in the article the gear whine noise which is a single-order noise can be extracted from the complicated power train noise band

and the improvement then can be made afterward.