【国外标准】 Standard Test Method for Evaluating the Thermal Stability of Manual Transmission Lubricants in a Cyclic Durability Test

5.1 This test method is used to evaluate automotive manual transmission fluids for thermal instability, which results in deterioration of synchronizer performance.5.2 This test method may also be utilized in other specifications and classifications of transmission and gear lubricants such as the following:5.2.1 (final API designation of PG-1),5.2.2 Military Specification MIL-L-2105,5.2.3 SAE Information Report J308 Axle and Manual Transmission Lubricants, and5.2.4 Mack Truck GO-H Gear Lubricant Specification.1.1 This test method covers the thermal stability of fluids for use in heavy duty manual transmissions when operated at high temperatures.1.2 The lubricant performance is measured by the number of shifting cycles that can be performed without failure of synchronization when the transmission is operated while continuously cycling between high and low range.1.3 Correlation of test results with truck transmission service has not been established. However, the procedure has been shown to appropriately separate two transmission lubricants, which have shown satisfactory and unsatisfactory field performance in the trucks of one manufacturer.1.4 Changes in this test method may be necessary due to refinements in the procedure, obsolescence of parts, or reagents, and so forth. These changes will be incorporated by Information Letters issued by the ASTM Test Monitoring Center (TMC). The test method will be revised to show the content of all the letters, as issued.1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.5.1 Exception—When materials, products, or equipment are available only in inch-pound units, SI units are omitted.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 This test method is arranged as follows:  Section  1Referenced Documents  2Terminology  3Summary of Test Method  4  5Apparatus  6 Test Transmission  6.2 Transmission Mounts  6.3 Oil-Circulating System  6.4 Oil Return Hole  6.5 Air Pressure Controls  6.6 Drive System  6.7 Instrumentation  6.8 Thermocouple Placement  6.9Reagents and Materials  7Safety  8Preparation of Apparatus  9 Cleaning of Parts  9.1 Assembly  9.2Calibration  10 Transmission and Test Stand Calibration  10.1 Reference Oils  10.2 Reference Oil Test Frequency  10.3 Instrumentation Calibration  10.4 Shift Time Calibration  10.5Operating Procedure  11 System Flush and Charge  11.1 Test Operation  11.2 Shut-Down Procedure  11.3 Transmission Disassembly  11.4Determination of Test Results  12 Failure Criteria  12.1 Shifter Fork Wear  12.2 Test Validity Determination  12.3Report  13Precision and Bias  14Keywords  15Test Validity Calculations and Limits Annex A5HTCT Test Report Forms and Data Dictionary Annex A6Manual Transmission Cyclic Durability Test Parts Inspection and Wear Measurements Annex A71.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.