Область применения

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. 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 and health practices and determine the applicability of regulatory limitations prior to use.

1.7 This test method is arranged as follows:

SectionScope1 Referenced Documents2Terminology3 Summary of Test Method4Significance and Use5Apparatus6Test Transmission6.2Transmission Mounts6.3 Oil Circulating System6.4Oil Return Hole6.5Air Pressure Controls6.6Drive System6.7Instrumentation6.8 Thermocouple Placement6.9Reagents and Materials7Safety8Preparation of Apparatus9Cleaning of Parts9.1Assembly9.2 Calibration10Transmission and Test Stand Calibration10.1Reference Oils10.2 Reference Oil Test Frequency10.3Instrumentation Calibration10.4Shift Time Calibration10.5 Operating Procedure11System Flush and Charge11.1Test Operation11.2Shut Down Procedure11.3Transmission Disassembly 11.4Determination of Test Results12Failure Criteria12.1Shifter Fork Wear12.2Test Validity Determination12.3Report13 Precision and Bias14Keywords15 Test Validity Calculations and LimitsAnnex A1Test Kit PartsAnnex A2Report FormsAnnexA3Data DictionaryAnnex A4Manual Transmission Cyclic Durability Test Parts Inspection and Wear MeasurementsAnnex A5