A Comparison of Methods for Testing Rubber Materials in Automatic Transmission Fluids

Rubber material testing in automatic transmission fluids is traditionally done using ASTM D471. This test was designed to be an accelerated test and does not best simulate the transmission environment. An initial comparison of the ASTM test to three specially designed tests is presented here. The objective is to evaluate the tests with data from different fluids and rubber materials and identify the best laboratory method of determining the long-term behavior of a rubber compound in an automotive transmission.