Abstract
By using the simple model of the powertrain system of a vehicle equipped with an automatic transmission, a computer program simulating the transmission endurance test mode is developed. Both the analysis and the experiment on the three vehicles with the different properties are performed to compare the results. The predicted cumulative damage to the gear and the bearing in the automatic transmission shows good agreement with the experimental results. This study enables the transmission engineers to take into account the influence of various properties of the engine, transmission and vehicle on the durability of the automatic transmission quantitatively.