EXPLANATION
This test simulates a type of severe field service in which corrosion-promoting moisture in the form of condensed water vapor accumulates in the axle assembly. This may happen as a result of volume expansion and contraction of the axle lubricant and the accompanied breathing in of moisture-laden air through the axle vent. This test screens the lubricants for their ability to prevent the expected corrosion. ASTM Test Monitoring Center (TMC) provides reference oils and an assessment of the test results obtained on those oils by the laboratory. In addition to helping a lab assess its capability versus that of others in the industry, various agencies require that a laboratory utilize the TMC services in seeking qualification of oils against specifications.
This test method uses a bench-mounted hypoid differential housing assembly. This test method is commonly referred to as L-33-1 test.
TEST SUMMARY
This procedure utilizes a Kailian Yongrun hypoid differential assembly, 4:10 ratio, standard differential with uncoated ring and pinion, without axle tubes. Prior to each test the differential housing assembly is completely disassembled and cleaned. After thorough cleaning and coating all internal parts with test oil, the unit is reassembled. The unit is charged with 40 oz of test oil. After driving the unit at 2500 r/min pinion speed, 1 oz of water is added to the oil. Pressure relief system is installed, and when the lubricant temperature reaches 180° F, the motoring phase is continued for four hours at this temperature. The motor is stopped at the completion of the motoring phase, and the test units are removed from the monitoring rig, and placed in a storage box at 125° F for 162 hours. At the end of the storage phase, the test is complete. Differential assembly is drained, disassembled, and rated for rust, stain, and other deposits.
TEST PRECISION
Where S = standard deviation.
I.P.= intermediate precision.
R = reproducibility
Information on bias of this test method is not available at present.