The gear rattle noise is analyzed from the perspective of energy fluctuation and a metric named"energy fluctuation metric"is proposed Barbecue Cover for the evaluation of gear rattle.A transmission system dynamics model is established with ADAMS software and "energy fluctuation metric"is used to analyze transmission gear rattle noise.The simulation analysis is compared with experiment test data and subject evaluation.In addition,the gear rattle threshold is determined.It is found that "energy fluctuation metric"has a good effect on evaluating gear rattle noise and it could be used Ski de fond - Enfant - Skis - Classic to improve transmission performance.