SAE J1266 pdf download
SAE J1266 pdf download.Axle Efficiency Test Procedure.
11.1 Data from this SAE Recommended Practice permit mapping axle efficiency and/or waste energy over the operating range of trucks, busses, and other highway vehicles based on truck chasses
12 The procedure can be applied to single axles, tandem axles as a system. or other systems, by combining separate tests, such as tests 01 the front axle and power divider and rear axle of tandem or tfl-&ive type.
2. References—There are no referenced publications specified herein.
3. Objecltves
3.1 To provide a means for measuring and comparing axle efficiency and the influence of matenals. lubricants. and design factors on axle efficiency
32 To outline a series of tests which encompass the typical range of axle operation in terms of load. speed. and lubricant temperature.
3.3 To result m data which are comparable from one test to another and between laboratories.
4. EquIpment Requirement
4.1 An axle dyriamometer with torque and speed capabilities consistent with the size axle being tested Separate absorbers for each output are preferred
42 A separate test stand without absorbers for the no4oad portion ol the test is optional.
4.3 CapabIlity of measuring irut speed with an accui’acyot ±1% of the actual speed.
4.4 Capability of measuring all torques specified with an accuracy of ±0.5% of the actual torque
45 Means br measuring and controlling sump lubncant temperatures to ±6.0 DC for steady-state temperature test sequences,
4.6 Means for cold soaking the axle assembly to -35 C when efficiency at low tempeiale is to be measured.
5 Test Preparation
5.1 The test axle is to be representative of the pailicular axle design. Setting of bearing preloads. backlash, etc.. outside of design specification units is permissible only if that is the purpose of the test T?ils applies to production and experimental designs.
5.2 To preclude differential gear rotation as a source of inefficiency, all differentials are to be locked or mechanically blocked from rotating.
NOTE— Some dynamometers with automatic feedback systems to control reLative speeds of absorbers may require deactivation of the feedback system.
5.3 The axle is to be equipped to measure sumnp terrerature
5.4 The axle assembly is to be tested at the attitude in which it would be installed in a vehicle, unless otherwise 8.
5.5 The axle is to be filled with lubricant recommended for in-vehicle use or the specific lubricant being evaluated.
5.6 Lubricant quantity Is to be the axle manutaclure?s recommendation by mass or volume, unless lubricant quantity is a variable under test.
5.7 Calculate output speeds arid output torque for the break-in and test sequence. See Figure 1 arid 7.3.
5.8 Calculate power requirements and determine whether break -in or test sequence must be modified as outlined in 6.1 arid 7.3.
NOTE— It a tandem front axle is to be tested separately. the rated test torque for each axle would be one half the tandem rating.
6. Break-In—An axle is considered to have passed through the breakn period when the efficiency of the axle has stabilized. To minimize the running time required for axles to achieve efficiency stabilization, select the eppropniate schedule from 61 and 62. Previously-run axles and axles in which the lubricant has been changed may not be completely stabilized. Therefore, all test axles ae to be stabilized in the selected break- in schedule before final testing
6.1 It 125% of rated torque at 65 krnTh does not exceed realistic in-service horsepower for the axles, run new axles for break-in to the following sequence at 65 kmih:
a. 50% of rated output torque for 90 mm
b. 100% of rated output torque for 120 mm
c. 125% of rated output torque for 90 awn
6.2 To determine friction stability, measure the efficiency at the stait. middle, and end of each break-in load selling run. If friction has not stabilized during the highest load run, repeat the total break-in schedule.
