SURFACE TEMPERATURES AND FRICTION IN LUBRICATED CLUTCHES

Clutch plate surface temperatures have been measured during clutch engagement using a clutch machine that simulates clutch application in an automatic transmission. Clutch surface temperatures were found to depend upon such parameters as clutch plate sliding speed, number of clutch plates in the clutch, rate of clutch engagement, lubricant type, and lubricant sump temperature.

With this same machine, friction between clutch plates was found to be affected by lubricant type, lubricant sump temperature, and number of clutch plates used. It was also found that a correlation existed between friction and automatic transmission shift performance.