This specification provides a list of test methods and acceptance criteria for determining the performance acceptability of gear lubricants used in nonsynchronized heavy duty manual transmission (MT-1). The test methods listed here shall be able to examine the following properties of the gear lubricants: viscosity increase; pentane insolubles; toluene insolubles; carbon/varnish rating; sludge rating; hardness and volume change, and elongation of polyacrylate and fluoroelastomer; falling load stage; and foam tendency. This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.