ASTM D6121 Test Method for Evaluation of the Load Carrying Capacity of Lubricants
ASTM D6121 Standard Test Method for Evaluation of the Load Carrying Capacity of Lubricants Under Conditions of Low Speed and High Torque Used for Final Hypoid Drive Axles
8. Preparation of Apparatus
8.1 Cleaning of Reusable Hardware - Clean as necessary all reusable parts including: axle shafts, thermocouples axle housing cover, and all associated drain pans and funnels used for the addition of and collection of test oil.
8.2 Preparation of Axle:
8.2.1 Pretest Pattern Procedure (optional) - Check pinion and ring gear pattern in accordance with Dana procedures. Make adjustments as necessary to allow the test unit to have a gear tooth pattern centered on the drive side of the gear teeth.
8.2.2 Cleaning - Wash the test unit, using hydrocarbon solvent (Warning - see 7.2), paying particular attention to the pinion bearings to remove all preservative oil. Dry by blowing with clean, dry compressed air.
8.2.3 Install axle shafts in test unit.
8.2.4 Lubricate the carrier bearings, pinion bearings, differential gears, and the ring gear and pinion, using the test lubricant or neutral base oil.
8.2.5 Break and Turn Torque Measurements - Determine and record the torques required to break and to turn the pinion shaft of the completely assembled test unit.
8.2.6 Backlash Measurements - Remove the cover plate. Record backlash at four equally space locations. The average of the four readings shall be from 0.004 to 0.009 in. (0.102 to 0.229 mm).
8.3 Install the test unit on the stand with pinion and axle shaft centerlines horizontal. Connect dynamometers and drive shaft to the test unit.
8.4 Bolt the axle cover with gasket (apply sealant, if needed) onto the axle housing and fill the axle assembly with 6.0 +/- 0.1 pt. (2.8 +/- 0.05 L) of test lubricant. This step may occur before or after the test unit is installed on the stand as described in 8.3.
9. Calibration and Standardization
9.1 Reference Oils and Hardware:
9.1.1 Reference oils for stand calibration are available from the ASTM Test Monitoring Center (TMC) and approved hardware through ASTM D02.B0.03.
9.1.2 Do not submit reference oils to physical or chemical analyses for identification purposes. Identifying the oils by analyses could undermine the confidentiality required to operate an effective blind reference oil system. Therefore, reference oils are supplied with the explicit understanding that they will not be subjected to analyses other than those specified within this procedure unless specifically authorized by the TMC. In such cases where analyses are authorized, supply written confirmation of the circumstances involved, the data obtained, and the name of the person authorizing the analysis to the TMC.
9.2 Stand Calibration:
9.2.1 Laboratories wishing to calibrate test stands using reference oils and approved hardware shall participate in the Lubricant Test Monitoring System calibration program administered for this test method by the TMC (see Annex A1). The TMC distributes reference oils as blind coded samples for test stand calibration. Report all test starts and test data using reference oils to the TMC. Calibration frequency is subject to change as required. Current calibration information is available from the TMC. Send all reference oil test results to the TMC within five (5) days of test completion. Extensions to this response time may be granted only with prior approval of the TMC.
9.2.2 The TMC shall inspect new test stands for compliance with this test method. A test stand is considered new when a test stand is moved. Additionally, circumstances involving significant changes to stand apparatus, instrumentation, and operation may require an existing test stand to meet new test stand calibration requirements. Consult with the TMC regarding these matters.
9.2.3 Reference Test Frequency - One reference test is required every two months or after 650 test hours on non-reference fluids, whichever occurs first.
9.2.4 When a test stand is out of calibration for a period of six months or longer, renumber the stand, and follow LTMS guidelines for new stand introduction.
9.2.5 Report modification of test stand apparatus or completion of any nonstandard test on a calibrated test stand to the TMC immediately. The TMC will determine whether another calibration test is necessary.
9.2.6 Alternate testing of L-37 and L-42 tests does not necessitate re-calibration as long as the above requirements are met.
9.3 Every test start on any test stand shall receive a sequential test run number designated before testing begins. All tests, including aborted starts and operationally invalid tests, must retain their test number.
9.4 Instrumentation Calibration - Calibrate the axle speed measuring system, temperature control system, and torque measuring system to occur at a maximum of four months or 50 tests against a known standard traceable to the National Institute of Standards and Technology (NIST) or a physical constant.
