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
6. Apparatus
6.1 Test Unit - The test unit is a new complete hypoid truck axle assembly less axle shafts, Dana Model 60, 5.86 to 1 ratio. See Annex A6 for part numbers.
6.2 Test Stand and Laboratory Equipment:
6.2.1 Axle Vent - Vent the axle to the atmosphere throughout the entire test and arrange the vent so that no water enters the housing.
6.2.2 Axle Cover - The axle cover has a 3.5-in. (8.9-cm) inspection port installed, as shown in Fig. A2.1. This allows filling the axle and provides a means for inspecting the axle after the gear condition phase (see 10.1). Install a thermocouple, as described in 6.2.4.1
6.2.3 Test Stand Configuration - Mount the complete assembly in a rigid fixture as shown in Fig. A3.1. Mount the test unit in the test stand with pinion and axle shaft centerlines horizontal.
6.2.4 Temperature Control - The test axle housing shall include a means of maintaining the lubricant at a specified temperature. This shall include a thermocouple, a temperature recording system, and a cooling method.
6.2.4.1 Thermocouple - Determine the thermocouple location on the rear cover using the cover plate temperature sensor locating device as shown in Fig. A4.1. Install the thermocouple such that the tip extends 0.5 in. (1.27 cm) towards the ring gear form the inside surface of the cover.
6.2.4.2 Temperature Recording System - The temperature recording system shall record the temperature of the test oil throughout the test.
6.2.4.3 Axle Cooling - Use three spray nozzles to distribute water over the cover plate and axle housing as shown in Fig. A5.1. Actuate the water control valve by the temperature control system.
6.2.5 Power Source - The power source consists of a gasoline-powered V-8 engine capable of maintaining test conditions.
6.2.6 Dynamometers and Torque Control System - Use two axle dynamometers with sufficient torque absorbing capacity to maintain axle torque and speed conditions. Suitable control equipment with sensitivity of adjustment to permit maintenance of test conditions is required.
6.2.7 Dynamometer Connecting Shafts - Fabricate shafts connecting the dynamometer to the axle shafts. Shafts must be strong enough to handle the torques encountered and be balanced up to 1200 r/min.
6.2.8 Drive Shaft and Universal Joints - Fabricate a shaft with universal joints connecting the manual transmission and test axle. The shaft shall have a 4-in. (10.1-cm) outside diameter with a 0.094-in. (0.26-cm) wall thickness. Shaft and universal joints should be strong enough to handle the torques encountered and be balanced up to 5000 r/min.
6.2.9 Transmission and Coupling - Couple the engine to the test unit through a clutch and manual transmission of sufficient torque carrying capacity to operate normally under test conditions.
6.3 Speed Measuring and Control System, capable of measuring speed of both axles and also to maintaining test conditions.
7. Reagents and Materials
7.1 Sealing Compound, where necessary, Permatex No. 2, or equivalent.
7.2 Solvent, hydrocarbon solvent that will evaporate at room temperature, leaving no residue. (Warning - Combustible, vapor harmful.)
