Taking a light truck transmission as the research object

the finite element modal analysis of transmission coupling system is carried out by using the Workbench software.The modal frequency and corresponding modal vibration modes is obtained

and by calculating the engine vibration frequency

the gear-meshing frequency and the input shaft and output shaft frequency

the engine and transmission will not occur a coupling vibration phenomenon is proved.At the same time

there are several frequencies that they could spur the transmission coupling system.A theory basis for the dynamic response analysis and fault diagnosis of the transmission coupling system is provided.