This SAE Recommended Practice is intended as a guide toward implementation of a standard practice but may be subject to frequent change to keep pace with experience and technical advances. This should be kept in mind when considering its use. The SAE No. 2 Friction Test Machine is used to evaluate the friction characteristics of automatic transmission plate clutch with automotive transmission fluids. It can also be used to conduct durability tests on wet friction systems. This document is intended for common use by both suppliers and end users to deine minimum test machine requirements to allow objective comparisons for wet friction material system performance.