ASTM D 5579:2019

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 Scope 1 Referenced Documents 2 Terminology 3 Summary of Test Method 4 Significance and Use 5 Apparatus 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 6.9 Reagents and Materials 7 Safety 8 Preparation of Apparatus 9 Cleaning of Parts 9.1 Assembly 9.2 Calibration 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 10.5 Operating Procedure 11 System Flush and Charge 11.1 Test Operation 11.2 Shut-Down Procedure 11.3 Transmission Disassembly 11.4 Determination of Test Results 12 Failure Criteria 12.1 Shifter Fork Wear 12.2 Test Validity Determination 12.3 Report 13 Precision and Bias 14 Keywords 15 Test Validity Calculations and Limits Annex A5 HTCT Test Report Forms and Data Dictionary Annex A6 Manual Transmission Cyclic Durability Test Parts Inspection and Wear Measurements Annex A7 1.8 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.

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