ASTM D4998 Standard Test Method for Evaluating Wear Characteristics of Tractor Hydraulic Fluids
4. Summary of Test Method
4.1 A modified FZG gear oil test machine is operated for 20 h under controlled conditions of speed (100 r/min), torque (tenth stage), and temperature (121 °C). Test gears are lubricated with the test oil.
4.2 The test gears are weighed and visually examined before and after the test. The gear mass loss and the visually observed damage to the gear teeth are used to evaluate the wear obtained with the test fluid.
5. Significance and Use
5.1 Many modern tractor designs use the hydraulic fluid to lubricate the transmission and final drive gears. This test method is used to assess the suitability of the tractor hydraulic fluids as lubricants for transmission and final drive gears of tractors.
