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For vehicles that employ a front engine and front wheel drive (FWD) system with a transverse engine layout, the mounting insulators for installation of the power plant require the following five performance items: ➀ Minimization of shock transmission from the power plant to the vehicle body when accelerating or when changing gears. ➁ Minimization of engine vibration transmission when the engine is idling. ➂ Reduction of vertical vibration of the vehicle body due to input from the road. ➃ Reduction of unfavorable shock resulting from the delay in movement of the power plant against the vehicle body due to lateral acceleration exerted when steering the vehicle. ➄ Blockage of noise transmitted from the engine and transmission. Up until now, there has been no effective means of adjusting the mounting insulators so that all five required performance items can be satisfied at the same time.

This paper examines the anti-shudder property of automatic transmission fluid (ATF) in terms of evaluation criteria and durability. The anti-shudder property is required for precise slip control around the clutch in that kind of automatic transmission, applications which are currently increasing. To evaluate anti-shudder properties, friction characteristics are measured by modified Low Velocity Friction Apparatus (LVFA), and the data are compared with those from the actual vehicle. The analysis confirms that the occurrence of shudder on the vehicle is closely related to the ratio of the static friction coefficient to the dynamic one measured by modified LVFA.

It has been over a half century since automatic transmission vehicles were introduced to the market, and many improvements in terms of reliability, performance, and cost have since been made. As a result, over 70 percent of passenger cars in the Japanese market today are equipped with automatic transmissions. Despite these advances, customer demand for quieter operation and reduced vibration in automatic transmission vehicles requires further improvements, particularly in the area of reduced shock and smooth response during shifting. Technological improvements have been in progress to solve this problem by such means as reducing engine output during shifting, adapting feedback control and learning shift control. Consequently, an advanced evaluation method for shift quality, with accuracy matching that of human feeling, is required to help improving the shift quality of automatic transmissions.