NB/SH/T 0518-2016 Evaluation of load-carrying capacity of vehicle gear oils L-37 method

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Card type: Test method

1. Method number / full name / English name / replacement relationship

• Standard number: NB/SH/T 0518—2016
• Chinese name: Evaluation of load-carrying capacity of vehicle gear oils L-37 method
• English name: Standard test method for evaluation of load-carrying capacity of lubricants under conditions of low speed and high torgue used for final hypoid drive axles (transcribed as in the source text, torgue suspected to be torque, requires confirmation against the source standard (source-text extraction))
• Replacement relationship: replaces SH/T 0518—1992 "Evaluation Method for Load-Carrying Capacity of Vehicle Gear Oils (L-37 method)"
• Adoption relationship: modified adoption using the redrafting method of ASTM D6121-14 "Standard Test Method for Measuring the Load-Carrying Capacity of Vehicle Gear Oils"
• Publication/implementation: published on 2016-12-05, implemented on 2017-05-01
• Publishing unit: National Energy Administration
• Drafting unit: Sinopec Research Institute of Petroleum Processing
• Main drafters: Chen Dazhong, Song Haiqing, Fan Jinshi
• Custody: National Technical Committee for Standardization of Petroleum Products and Lubricants, Subcommittee on Petroleum Fuels and Lubricants (SAC/TC280/SC1)
• Proposed by: China Petrochemical Corporation

2. Scope of application and non-applicability

• This standard specifies a method for evaluating the load-carrying performance, anti-wear performance and extreme pressure performance of vehicle gear oils under low-speed high-torque conditions using a hypoid gear drive axle. This test method is commonly referred to as the L-37 test.
• This standard is applicable to evaluating the load-carrying, anti-wear and extreme pressure performance of vehicle gear oils.
• This standard also provides a Canadian low-temperature test procedure for operating the L-37 drive axle. Except for the specified items listed in Annex D.2, the L-37 drive axle Canadian low-temperature test procedure is the same as the standard L-37 test procedure. The modified procedure listed in Annex D.2 applies to the corresponding clauses of the L-37 standard test method.
• Note: The numerical units in this standard use the [SI] International System of Units, and the numerical values in parentheses use English units.
• Non-applicable scope: not provided in the available source.

3. Method principle

• 4.1 Before the test, inspect and measure the test unit (drive axle assembly), record and check the factory specifications.
• 4.2 After installing the drive axle assembly, fill with test oil.
• 4.3 Gear run-in stage: the test drive axle is operated at a speed of 440 r/min, with each dynamometer applying a load of 535 N·m, for 100 min, and the test oil temperature is maintained at 147 ℃ (the original 4.3 temperature value source-text extraction is shown as "147Y", which in combination with 10.1.1 should be 147.2 ℃±1.7 ℃, requires confirmation against the source standard (source-text extraction)).
• 4.4 Gear test stage: next, according to the test conditions specified for the rear axle batch number and type, operate the test for 24 h (see 10.2).
• 4.5 At the end of the gear test stage, score the test parts such as the ring gear and drive gear. Evaluate the performance of the test oil according to the tooth surface damage of the ring gear and drive gear.
• 5 Method application: used to evaluate the ability of lubricating oil to protect the drive axle from abrasive wear, adhesive wear, plastic deformation and surface fatigue under low-speed high-torque conditions. When lubricating oil lacks these properties, it will lead to premature failure of gears and/or bearings.

4. Reagents and materials (purity / preparation)

• 7.1 Sealing material: Permatex brand 2 non-drying sealant, or a sealant with equivalent performance.
• 7.2 Solvent naphtha: required to comply with ASTM D235 class II grade C solvent naphtha or comply with GB 1922—2006 No. 4 solvent naphtha, and the Saybolt color number is not less than +25 or the platinum-cobalt color number is not greater than 25.
• Warning: solvent naphtha poses combustion and volatilization hazards.
• Test oil amount: 2.8 L±0.05 L (see 8.2.6).
• Other reagent purity and preparation methods: not provided in the available source.

5. Instruments and equipment

• 6.1 Test unit: a brand-new and complete hypoid truck drive axle assembly manufactured by Dana (DANA) with model 60 and speed ratio 5.86:1, and this drive axle is not equipped with axle shafts. See Annex D.2 for part numbers.
• 6.2 Test bench and test unit:
  • 6.2.1 Drive axle vent: throughout the entire test, arrange venting reasonably so that the drive axle vent is connected to the atmosphere, preventing water from entering the drive axle through the vent.
  • 6.2.2 Drive axle rear cover: the rear cover has an observation hole with a diameter of 89 mm, as shown in Figure D.1 of Annex D. It is used for filling test oil and for inspecting the drive axle gears after the gear run-in test stage is completed. Install a thermocouple as described in 6.2.4.2.
  • 6.2.3 Test bench installation: install the complete drive axle on a rigid bench according to Figure D.2. Install the entire drive axle horizontally on the test bench according to the centerlines of the drive pinion and rear axle.
  • 6.2.4 Temperature control:
    • 6.2.4.1 The test drive axle housing should be able to control the lubricating oil at the specified temperature. The temperature control system should include a thermocouple, a temperature recording system and cooling measures.
    • 6.2.4.2 Thermocouple: use the rear cover temperature sensor positioning device to position the thermocouple on the rear cover plate, as shown in Figure D.3 in the annex. a) Install the thermocouple so that the end of the thermocouple is flush with the lip of the rear cover plate. Place the rear cover plate on a flat surface, and insert the thermocouple into the rear cover plate until the end of the thermocouple is flush with the flat surface. b) Lock the thermocouple on the rear cover.
    • 6.2.4.3 Temperature recording system: capable of recording the test oil temperature throughout the entire test period.
    • 6.2.4.4 Drive axle cooling:
      • 6.2.4.4.1 Use three nozzles to spray cooling water onto the drive axle rear cover and housing, as shown in Figure D.4 in the annex. The cooling water valve is controlled by the temperature control system using the proportional-integral-derivative (PID) method. See Annex D.2.3.2.1 for the test description of the L-37 Canadian version drive axle model. Nozzle part numbers: straight male connector NPT (No. 3/8CG-SS22), 90° male connector NPT (No. 3/8GGA-SS22), straight female connector NPT (No. 3/8G-SS22), 90° female connector NPT (No. 3/8GASS22).
      • 6.2.4.4.2 Use a single control valve to control the cooling water. The control valve is selected as a 12.7 mm (1/2 in) two-way, with C linear adjustment function, air-to-close, research-type control valve. Use a single PID loop to control the test oil temperature of the standard model drive axle and the Canadian model drive axle. It is not permitted to use separate PID loops to control different drive axle models. See Annex D.2.3.2.2.
      • 6.2.4.4.3 Pipelines of 9.5 mm (3/8 in) or 12.7 mm (1/2 in) should be used to connect the nozzles.
      • 6.2.4.4.4 The water pressure supplied to the control valve cannot be less than 25 kPa.
      • 6.2.4.4.5 Use a drive axle housing cover as shown in Figure D.5 in the annex to store cooling water and reduce cooling water consumption.
      • 6.2.4.4.6 Use positioning pins or brake blocks as positioning devices to ensure that the drive axle rear cover installed each time is perpendicular to the centerline of the engine and transmission drive shaft.
  • 6.2.5 Power source: composed of a V-type 8-cylinder gasoline engine capable of meeting the test conditions.
  • 6.2.6 Dynamometer and torque control system: use two dynamometers with sufficient torque absorption capacity to maintain the drive axle torque and speed. A suitable set of control equipment is required to maintain the test state.
  • 6.2.7 Dynamometer connecting shaft: the connecting shaft used to connect the dynamometer and the drive axle should have sufficient strength to carry the generated torque and maintain dynamic balance.
  • 6.2.8 Drive shaft and universal joint: a drive shaft with universal joint used to connect the manual transmission and the test drive axle. Drive shaft outer diameter: 10.1 cm±0.51 cm, wall thickness: 0.24 cm±0.013 cm. The drive shaft and universal joint should have sufficient strength to carry the generated torque and maintain dynamic balance.
  • 6.2.9 Transmission and clutch: the engine and test drive axle are coupled through the clutch and manual transmission, and the clutch and transmission can maintain normal operation with sufficient torque-carrying capacity under the test conditions.
• 6.3 Speed measurement and control system: capable of measuring the speeds of the two axle shafts and maintaining the test conditions.

6. Recommended operating conditions

• Gear run-in stage (10.1):
  • Test oil temperature: 147.2 ℃±1.7 ℃ (for L-37 Canadian version test conditions see Annex D.2).
  • Speed: 440 r/min±5 r/min.
  • Torque: 533 N·m±20 N·m (the original 10.1.2 contains two occurrences, "535N, m" and "533N．m", requires confirmation against the source standard (source-text extraction)).
  • Time: 100 min±1 min.
  • Record speed, load and temperature at least once per minute.
  • 100 After the min operation is completed, when the load and speed have begun to decrease, set the drive axle temperature controller temperature to 135.0 ℃. Shift into neutral and confirm that the drive axle has stopped rotating. Record the end time and test oil temperature.
• Gear test stage (10.2):
  • Test oil temperature: 135.0 ℃±1.7 ℃ (for L-37 Canadian version test conditions see Annex D.2).
  • Speed: 80 r/min±1 r/min.
  • Torque: 1415 N·m±47 N·m, maintain this condition until the test oil temperature rises to 79.4 ℃±1.7 ℃.
  • When the test oil temperature rises to 79.4 ℃±1.7 ℃, immediately apply load to each dynamometer and increase it to 2359 N·m±47 N·m.
  • When testing with an uncoated gear drive axle with batch number VIL500/P4T813, a reduction of 13% contact stress is required (see Appendix D.2.4).
  • Time: 24 h±0.2 h.
  • Record speed, load and temperature at least once per minute.
  • After the 24 h operation ends, smoothly close the throttle, shift into neutral, and record the end time and test oil temperature.
• Test version (Appendix D.2.2 Table D.1):
  • Standard/uncoated: gear run-in stage oil temperature 147.2 ℃±1.7 ℃, gear test stage oil temperature 135.0 ℃±1.7 ℃.
  • Standard/coated: gear run-in stage oil temperature 147.2 ℃±1.7 ℃, gear test stage oil temperature 135.0 ℃±1.7 ℃.
  • Canada/uncoated: gear run-in stage oil temperature 104.4 ℃±1.7 ℃, gear test stage oil temperature 93.3 ℃±1.7 ℃.
  • Canada/coated: gear run-in stage oil temperature 104.4 ℃±1.7 ℃, gear test stage oil temperature 93.3 ℃±1.7 ℃.
  • All versions use the same dynamometer speed, load conditions and test procedure, as described in Chapter 10 of the method.
  • The two Canadian versions are typically used to evaluate lubricating oils with a viscosity of 75W.

7. Sampling and specimen preparation

• 8.1 Cleaning reused parts: Clean all reused parts, including drive axle half-shafts, drive axle rear cover with thermocouple, drain pan, and funnels used for filling and collecting test oil.
• 8.2 Drive axle preparation:
  • 8.2.1 Record the drive-side contact pattern length and flange values marked "acceptable" by DANA company on the drive axle housing. Drive axles marked with length values "L1", "L2", "L3" and flange values "F-1", "F", "F1" are all acceptable. Any adjustments made to the drive axle before testing shall be recorded in the comments column of the test report. For gear batch drive axles without contact pattern markings, the laboratory shall record this in the test report.
  • 8.2.2 Measure and record the torque required to start and rotate the complete test unit drive pinion.
  • 8.2.3 Record the gear backlash reported by the manufacturer on the test drive axle. Manufacturer-reported gear backlash within the range of 0.102 mm~0.305 mm is acceptable.
  • 8.2.3.1 If the test drive axle does not have a manufacturer-reported gear backlash value, the average gear backlash value measured according to 8.2.3.2 shall be within the range of 0.102 mm~0.229 mm.
  • 8.2.3.2 Remove the rear cover plate and record the gear backlash at four equally spaced positions on the ring gear. Report the four readings and the average value.
  • 8.2.4 Clean the test unit using solvent naphtha (see 7.2), with special attention to removing all protective oil from the drive pinion bearings. Use clean dry compressed air to blow dry the cleaned test parts.
  • 8.2.5 Install the drive axle half-shafts in the test unit.
  • 8.2.6 Lubricate the differential bearings, drive gear bearings, differential gears, ring gear and drive gear. The test oil quantity is 2.8 L±0.05 L.
  • 8.2.7 Install the drive axle rear cover, adding a gasket (sealant may be applied if necessary). Once the specified amount of test oil has been added, draining or adding oil is not permitted.
• 8.3 Install the test unit: Install the test unit on the test stand with the centerline of the half-shafts horizontal, and connect the dynamometer and drive shaft to the test unit.
• Sampling: not provided in the available source.

8. Analysis procedure

• 9 Calibration and verification:
  • a) Newly established test stands shall be calibrated.
  • b) After 650 h non-reference oil tests, a calibration test shall be performed on the test stand.
  • c) Before each test stand calibration test, the drive axle speed measurement system, temperature control system and torque measurement system shall be calibrated according to a known standard, traceable to an authoritative or professional relevant organization.
• 10.1 Gear run-in stage:
  • 10.1.1 Set and control the test oil temperature at 147.2 ℃±1.7 ℃. L-37 For Canadian version test conditions, see Appendix D.2.
  • 10.1.2 After the engine is warmed up, with the dynamometer unloaded, smoothly shift to a gear that meets the test conditions. After shifting to the appropriate gear, smoothly increase the speed of each dynamometer to 440 r/min±5 r/min, and increase the torque to 533 N·m±20 N·m. The time to reach 440 r/min and load to 533 N·m test conditions is approximately 5 min.
  • 10.1.3 After reaching the required speed and torque conditions, start the gear run-in test and record the test start time.
  • 10.1.4 Under the conditions of reaching the speed and torque, continuously operate for 100 min±1 min.
  • 10.1.5 To ensure the accuracy of the test, record speed, load and temperature at least once per minute.
  • 10.1.6 After the 100 min operation ends, when the load and speed have begun to decrease, set the temperature controller of the drive axle to 135.0 ℃.
  • 10.1.7 Shift into neutral and confirm that the drive axle has stopped rotating. Record the end time and test oil temperature. L-37 For Canadian version test conditions, see Appendix D.2. Note: If the drive axle has not yet stopped rotating, it is permitted to continue spraying water on the drive axle while waiting for the test oil temperature to cool. Stop spraying water when the drive axle test oil temperature drops below the test oil temperature.
  • 10.1.8 If interrupted for some reason (power shortage, maintenance, etc.), restart the test as described in 10.3.1. Such an interruption during the test is considered one permitted shutdown. Before the test conditions are reached again, do not calculate deviation percentages or report out-of-limit operating values. If the shutdown occurs at the beginning of the gear run-in stage and the speed and load have not yet reached the test conditions, it cannot be counted as a permitted shutdown.
• 10.2 Gear test stage:
  • 10.2.1 Ensure the temperature control is set at 135.0 ℃±1.7 ℃. L-37 For Canadian version test conditions, see Appendix D.2.
  • 10.2.2 Warm up the engine and smoothly shift to a gear that meets the test conditions. Note: The transition time from the end of the gear run-in test stage to the appropriate gear required for the gear test stage is approximately 5 min.
  • 10.2.3 After shifting to the appropriate gear, smoothly increase the speed of each dynamometer to 80 r/min±1 r/min, and increase the torque to 1415 N·m±47 N·m. Maintain these conditions until the test oil temperature rises to 79.4 ℃±1.7 ℃. Note: It is required to reach the 80 r/min and 1415 N·m test conditions at around 10 min.
  • 10.2.3.1 When the test oil temperature rises to 79.4 ℃±1.7 ℃, immediately apply load to each dynamometer and increase it to 2359 N·m±47 N·m. When testing with an uncoated gear drive axle with batch number VIL500/P4T813, a reduction of 13% contact stress is required (see Appendix D.2.4).
  • 10.2.4 After the speed, torque and test oil temperature reach the required conditions, start the formal gear test and record this time as the test start time.
  • 10.2.5 After the speed, torque and test temperature reach the conditions, continuously operate for 24 h±0.2 h.
  • 10.2.6 To ensure the accuracy of the test, record speed, load and temperature at least once per minute.
  • 10.2.7 After the 24 h operation ends, smoothly close the throttle, shift into neutral, and record the end time and test oil temperature.
  • 10.2.8 With the test unit in a hot state, disconnect the drive shaft and the drive axle half-shafts connected to the dynamometer, and remove the test unit from the test stand.
  • 10.2.9 If the test is stopped for some reason, such as power problems, maintenance, etc., restart the test as described in 10.3.1. Such a stop during the test will be counted as one stop. Until the test conditions are reached again, do not calculate test deviation percentage values and operating out-of-limit values. If the stop occurs during this test stage but before the test conditions (speed, torque and test oil temperature) are reached, it is not counted as a stop.
• 10.3 Engine or test unit shutdown:
  • 10.3.1 Defined as any time during the gear run-in stage or gear test stage after stable test conditions have been entered, when the engine stops rotating, or both occur. After a planned shutdown, restart the test according to 10.3.1.1~10.3.1.5.
  • 10.3.1.1 During shutdown, set the temperature control to maintain the specified temperature condition value.
  • 10.3.1.2 After the engine is warmed up, with the dynamometer unloaded, smoothly shift to a gear that meets the test conditions.
  • 10.3.1.3 After shifting into the correct gear, smoothly accelerate the dynamometer to the speed setpoint of the test stage at the time of shutdown.
  • 10.3.1.4 When restarting after shutdown, apply torque to each dynamometer 1415 N·m±47 N·m, and maintain these conditions until the test oil temperature rises to 79.4 ℃±1.7 ℃.
  • 10.3.1.5 If the restart occurs during the gear run-in test stage, restart according to 10.1.4; when the test temperature rises to 79.4 ℃±1.7 ℃, immediately apply load to each dynamometer to the torque setpoint of the test stage at the time of shutdown.
• 11 Post-test drive axle measurement:
  • 11.1 Starting and rotating torque measurement:
    • 11.1.1 With the test unit in a hot state, measure and record the starting and rotating torque of the drive pinion in the complete test unit.
    • 11.1.2 After the test unit has cooled, measure and record the starting and rotating torque of the drive pinion in the complete test unit.
  • 11.2 Oil drain: Drain the test oil; the oil may be drained at any time after 10.2.7 is completed.
  • 11.3 Gear backlash measurement: Remove the drive axle rear cover plate, record the gear backlash measured at four equally spaced positions on the ring gear, and calculate the average of the four measured values.
  • 11.4 Completely disassemble the differential and pinion components in preparation for inspection.

9. Qualitative and Quantitative and Calculation Formulas

• 12.1 Drive gear bearing scoring: Refer to the "ASTM Damage Scoring Manual 21" to inspect the bearing for wear, surface fatigue corrosion, and deposits.
• 12.2 Gear scoring:
  • 12.2.1 Refer to the "ASTM Damage Scoring Manual 21" and Appendix D.5 to inspect the damage condition of the drive-side tooth surfaces of the ring gear and drive gear: polishing, wear, pitting/spalling, ridging, rippling, scoring, discoloration, corrosion, and deposits. Use the "ASTM Gear Damage Images" to score wear, rippling, and ridging damage. The images shall be those published by ASTM after 2010 year 11 month 9 day.
  • 12.2.2 Score each damage level according to Table D.3 in the appendix. Each damage level of the four damage types (ridging, rippling, scoring, wear) corresponds to a scoring value from 0 to 10, as shown in Table D.3 in the appendix. Table D.3 in the appendix also lists the scoring values corresponding to the damage levels of the pitting and spalling damage types.
  • 12.2.3 According to the requirements of Table 1, logarithmically transform the initial test scoring results to obtain the corresponding transformed values. Clause 12.3 lists the correction factors that should be added to the transformed values; the transformed values with the correction factors added are then inverse-log transformed to serve as the final reported test results.
• Table 1 Transformed Scores:
  • Ridging: -ln (10.5- merit score value)
  • Rippling: -ln (10.5- merit score value)
  • Pitting: -ln (10.5- merit score value)
  • Wear: None
• 12.3 Correction Factors and Non-Scoring Areas:
  • 12.3.1 When using an uncoated test drive axle with gear batch number CIL426/P4L415A to score pitting and spalling items, the scoring value cannot be any value between 9.3 and 9.9, and the scoring area does not include the wear step area on the drive surface of the drive pinion, as shown in Appendix D.6.
  • 12.3.2 When using an uncoated test drive axle with gear batch number V11303/P4L415A to score pitting and spalling items, the scoring value cannot be any value between 3.0 and 9.9, and the scoring area also does not include the wear step area on the drive surface of the drive pinion, as shown in Appendix D.6.
  • 12.3.3 When using a coated test drive axle with gear batch number VIL686/P4L626A, for non-reference oil tests, add correction factor 0.5186 to the transformed drive gear ridging test results, and add correction factor 0.9922 to the transformed ring gear ridging test results. Record these test results in the table of the test report. L-37 For the Canadian version test, see Appendix D.2.3.
  • 12.3.3.1 When using a test drive axle with gear batch number VIL686/P4L626A, a thin polishing line may exist at the root of the heel of the drive gear teeth and at the top of the ring gear teeth. Due to the machining positions of the drive gear and ring gear and the machining accuracy of the chuck, the length and degree of protrusion of the polishing line will vary. This is a normal condition and is unrelated to the test oil. In the comments column of the final test report, it must be noted that the polishing line of the test drive axle with batch number VIL686/P4L626A is caused during the gear machining process.
  • 12.3.4 When using an uncoated type test rear axle with gear batch number VIL528/P4T883A, for non-reference oil tests, add correction factor 0.3365 to the transformed drive gear ridging and rippling test results. Score pitting for each drive gear tooth, and report the fourth lowest score as the final drive gear pitting score result.
  • 12.3.4.1 Appendix D.2.2 lists the L-37 Canadian version test conditions.
  • 12.3.5 When using a coated test rear axle with gear batch number V1L528/P4T883A, for non-reference oil tests, add correction factor 0.3365 to the transformed drive gear ridging test results. Score pitting for each drive gear tooth, and report the second lowest score as the final drive gear pitting score result.
  • 12.3.5.1 Appendix D.2 lists the L-37 Canadian version test conditions.
• 12.4 Scoring by experienced personnel who have participated in professional training is considered valid scoring.
• 12.5 Test validity: If the percentage deviations of key operating parameters and the number of shutdowns are within the limits specified in Appendix D.4, the test is valid.
• 12.6 If a non-reference oil test is conducted on an uncalibrated bench, or using unapproved hardware, or both, note in the test report that the test results cannot be judged because the test was not conducted in the valid manner specified by the test method.
• 12.7 For either reference oil or non-reference oil tests, if one or more broken teeth occur on the drive gear or ring gear, the test results may be considered indeterminate. Note the broken tooth condition in the comments column of the test report.
• 12.8 Corrosion scoring is performed only on the contact surfaces of the drive pinion and driven ring gear drive surfaces. Fill in the corrosion score result in the scoring item of the scoring form. Record any corrosion in the non-contact areas of the drive gear and ring gear in the notes column of the scoring form.
• Appendix D.4.3.2 The deviation percentage is calculated according to formula (D.1): deviation percentage = [(time out of range at i) / (total test time of the test phase)] × 100 (the original formula source-text extraction is noisy, requires confirmation against the source standard (source-text extraction)).
• Appendix D.4.3.4 The deviation percentages of the operating parameters required to be controlled are shown in Table D.2 in the appendix: gear break-in phase limits (drive axle oil temperature 5%, dynamometer speed 5%, dynamometer load 5%); gear formal phase limits (drive axle oil temperature 5%, dynamometer speed 5%, dynamometer load 5%).
• Appendix D.4.3.5 If the drive axle oil temperature reaches 145.6 ℃ during the test, the test is considered invalid.
• Appendix D.4.3.6 During the gear break-in test, only after the temperature reaches 145.6 ℃ shall the calculation of the drive axle oil temperature deviation percentage begin.

10. Precision

• 14 Precision and bias: Judge the reliability of test results according to the following provisions (95% confidence level).
• 14.1 Precision: Note: Test precision is established on the basis of valid operating reference oil test results, which are monitored by TMC.
• 14.1.1 Intermediate precision:
  • 14.1.1.1 Intermediate precision conditions: The conditions for obtaining test results are within the same laboratory, using the same test method and the same test oil, and the following conditions may be changed, such as operator, measuring equipment, test bench, test engine, and time. Note: For this test method, intermediate precision is more appropriate than "repeatability" because repeatability specifies more stringent test conditions.
  • 14.1.1.2 Intermediate precision limit i.p.: Under intermediate precision conditions, the difference between two test results obtained using normal and correct test methods shall not exceed the value specified in Table 2.
• 14.1.2 Reproducibility:
  • 14.1.2.1 Reproducibility conditions: The conditions for obtaining test results are in different laboratories, with different operators, using different equipment, using the same batch of drive axles, the same test method, and the same test oil.
  • 14.1.2.2 Reproducibility limit R: Under reproducibility conditions, the difference between two single, independent test results obtained from long-term operation using normal and correct test methods shall not exceed the value specified in Table 2.
• Table 2 Reference Oil Test Precision Data (Coated Drive Axle):
  • Drive pinion ridging, merit score value: i.p. 1.430, R 4.004
  • Drive pinion rippling, merit score value: i.p. 0.476, R 1.333
  • Drive pinion pitting/spalling, merit score value: i.p. 0.579, R 1.621
  • Drive pinion wear, merit score value: i.p. 0.519, R 1.453
  • Drive pinion ridging, merit score value: i.p. 1.430, R 4.004
  • Drive pinion rippling, merit score value: i.p. 0.479, R 1.341
  • Drive pinion pitting/spalling, merit score value: i.p. 0.587, R 1.644
  • Drive pinion wear, merit score value: i.p. 0.563, R 1.576
• Table 2 Reference Oil Test Precision Data (Continued) (Uncoated Drive Axle):
  • Drive pinion pitting/spalling, merit score value: i.p. 0.666, R 1.935
  • Drive pinion wear, merit score value: i.p. 0.557, R 1.602
  • Drive pinion pitting/spalling, merit score value: i.p. 0.84, R 2.372
  • Drive pinion wear, merit score value: i.p. 0.713, R 1.996
  • Drive pinion pitting/spalling, merit score value: i.p. 0.691, R 1.935
  • Drive pinion wear, merit score value: i.p. 0.572, R 1.602
  • Drive pinion pitting/spalling, merit score value: i.p. 0.847, R 2.372
  • Drive pinion wear, merit score value: i.p. 0.713, R 1.996
• Note 1: These precision data were established from the test results of ... and 155 (the original source-text extraction is missing, requires confirmation against the source standard (source-text extraction)).
• Note 2: S.p. is the standard deviation; this value is obtained by multiplying the standard deviation by 2.8.
• 14.2 Bias: not provided in the available source.

11. Report

• 13.1 Issue the test report as shown in Appendix E.
• 13.2 The temperature recording curve is attached to the test report and serves as part of the test report.
• 13.3 Deviations from test operating parameter limits—the test report shall report all specified deviations from test operating parameter limits.
• Appendix E The test result report includes: Table E.1 Test Result Summary, Table E.2 Gear Tooth Surface Condition, Table E.3 Operating Parameter Summary, Table E.4 Shutdowns and Comments, Table E.5 Operating Validity Summary.
• Table E.1 test result summary includes: oil sample test, test equipment, completion date, total test time, test number, ring gear batch number, test version, last reference oil calibration bench information (only for non-reference oil tests), reference oil sample number, completion date, ring gear rating (wear, rippling, ridging, pitting/spalling, scoring), drive pinion rating (wear, rippling, ridging, pitting/spalling, scoring), original results, converted results, correction factor, corrected converted results, severity adjustment, final converted results, final rating results.
• Table E.2 gear tooth surface condition includes: test drive axle, pairing number, contact pattern length value, rater, tooth surface condition (polishing, discoloration, corrosion, deposits, wear, rippling, ridging, pitting/spalling, scoring), gear batch number identification, drive pinion batch number, installation date, contact pattern flange value, ring gear batch number, after completion of inspection of drive pinion and ring gear drive side in the gear formal test stage, original ring gear rating, original drive pinion rating, rating of non-rated tooth surface areas of the drive pinion (if present), comments on non-rated tooth surface areas as defined by the test method.
• Table E.3 operating parameter summary includes: drive pinion torque check (breakaway torque, turning torque), before test, after test end - hot, after test end - cold, operating conditions (gear break-in test stage, gear formal test stage), time, gear oil temperature, dynamometer torque, dynamometer speed, maximum, minimum, average, start, end.
• Table E.4 shutdowns and comments includes: test time, number of shutdowns, date, reason for shutdown, total, total shutdown time.
• Table E.5 operating effectiveness summary includes: control parameters (drive axle oil temperature, dynamometer speed 1, dynamometer speed 2, dynamometer load 1, dynamometer load 2), gear break-in stage limits, this test out-of-limit/%, actual out-of-limit time/(min:s), maximum allowable out-of-limit/%, gear formal stage limits, this test out-of-limit/%, actual out-of-limit time/(min:s), maximum allowable out-of-limit/%.

12. referenced documents

• GB 1922—2006 solvent naphtha for paints and cleaning
• GB/T 17754—2012 tribology terminology
• ASTM D235 specification standard for mineral (petroleum) solvents [Standard Specification for Mineral Spirits (Petroleum Spirits) (Hydrocarbon Dry Cleaning Solvent)]
• ASTM damage rating manual 21 ("ASTM Distress Rating Manual 21")
• ASTM D6121-14 standard test method for determining the load-carrying capacity of automotive gear oils (modified adoption)
• SH/T 0518—1992 evaluation method for load-carrying capacity of automotive gear oils (L-37 method) (replaced)
• GB/T 1.1—2009 drafted according to the rules given

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. quick Q&A reference