ASTM D1263 for leakage tendencies of automotive wheel bearing greases
9. Procedure
9.1 Weigh 90 more or less 1 g of sample on a flat plate. Pack with a spatula 2 more or less 0.1 g of grease in the small bearing and 3 more or less 0.1 g in the large bearing (Note 3). Distribute the balance of the test grease (85 g) in a uniform layer on the inside of the hub (Note 4). Apply a thin film of grease to the bearing races in the hub.

NOTE 3 - A narrow, wedge-cut spatula has been found of considerable aid in packing the bearings.

NOTE 4 - The balance of the test grease will fill the hub practically even with the races, and, with the exception of very fibrous greases, can be distributed readily and uniformly by use of a spatula having a 150-mm (6-in.) blade.

9.2 Weigh separately the leakage collector and the hub cap to the nearest 0.1 g. Place the leakage collector and the large (inner) bearing in the proper position on the spindle (Note 5). Put the hub and small (outer) bearing on the spindle, followed by the loose-fitting retainer ring (Note 6). With the torque wrench, tighten the hexagonal nut which holds the hub assembly in place, applying a torque of 6.8 more or less 0.1 N•m (60 more or less 2 lbf•in.). Then back off the hexagonal nut 60 more or less 5° (or one flat), and lock it in position with a second hexagonal nut. Screw on the hub cap, put the V-belt on the pulleys, and close the cabinet (Note 7 and Note 8).

NOTE 5 - Caution: All grease collectors should be inspected carefully to make sure that the inner lip is flush with the sealing face. Otherwise, this lip will interfere with the correct seating of the inner bearing.

NOTE 6 - Caution: In assembling the packed hub on the spindle, care should be taken to prevent contact between grease pack and spindle.

NOTE 7 - Caution: From time to time, the drive pulley and the driven pulley should be checked for alignment. Misalignment can introduce leakage variations.

NOTE 8 - Excessive end play of the hub assembly is sometimes due to worn bearings. Therefore new bearings, both cups and cones, should be installed after each 250 tests, or sooner if inspection indicates wear or other damage to the bearings.

9.3 After closing the cabinet turn on the motor and both heaters (Note 9). Operate at a speed of 660 more or less 30 rpm for 6 h more or less 5 min, the spindle temperature being raised to 105 more or less 1.4°C (220 more or less 2.5°F) then maintained for the balance of the test period. The spindle temperature of 105 more or less 1.4°C is obtained by maintaining an ambient temperature of 115 more or less 3°C (235 more or less 5°F). Leave the auxiliary heater on only until an ambient or oven temperature of 115°C is attained. It is desirable to have the thermoregulator previously adjusted to maintain a 115°C oven temperature, or to have a reproducible setting for this temperature. The ambient temperature of 115 more or less 3°C shall be attained within 15 more or less 5 min. The spindle temperature of 105 more or less 1.4°C shall be attained within 60 more or less 10 min. This combination results in the spindle holding 105 more or less 1.4°C for 5 h more or less 15 min.

NOTE 9 - Caution: Drafts can affect the rate of heating. Care should therefore be exercised in the location of the tester.

9.4 At the end of the 6-h test period, that is, 6 h from the time the motor and heaters are turned on, shut off the power and dismantle the apparatus while hot. Wear appropriate protective clothing to permit the handling of hot equipment.

9.5 After the apparatus has cooled, weigh separately the leakage collector and the hub cap to the nearest 0.1 g.

NOTE 10 - If the leakage collector overflows, the overflow grease or oil, or both, should be weighed and included in the total leakage reported.

9.6 Wash the two bearings in ASTM n-heptane (Warning - see Note 2) for at least 2 min at room temperature, to remove the grease (see Note 11). Inspect for varnish, gum, or lacquer-like deposits.

NOTE 11 - With some wheel bearing greases, it will be found that the soaps are not completely washed from the bearings with n-heptane. A film of soap may, therefore, remain on the bearings. This film can be readily distinguished from varnish, gum, or lacquer-like deposits resulting from deterioration of the lubricant.