This SAE Recommended Practice defines the principal terms and equations pertaining to automotive automatic transmission clutch plate, band, or other wet-friction systems. The terms apply directly to friction-system testing as is typically conducted on inertia-stop test equipment. Some terms can be directly applied to the analysis of friction in the transmission or brake assembly and other friction-test equipment. The glossary presents terms used to describe the set-up, testing, and results of tests as shown in Figure 1, which were taken on a clutch SAE No. 2 machine. The glossary is intended to provide a collection of definitions in the hope of eliminating confusion in terminology and a common set of terms for improving the state-of-the-art of friction-system development and their application to passenger cars and trucks. This document focuses on the terminology of friction-system testing. Reference for this type of testing are shown in Section 2.
The technical report covers technology, products, or processes which are mature and not likely to change in the foreseeable future.