ASTM D4290 for determining leakage tendencies of automotive wheel bearing grease
ASTM D4290 standard test method for determining the leakage tendencies of automotive wheel bearing grease under accelerated conditions
4. Summary of Test Method
4.1 The test grease is distributed in a modified, automobile front wheel hub-spindle-bearings assembly. While the bearings are thrust-loaded to 111 N, the hub is rotated at 1000 rpm and the spindle temperature maintained at 160°C for 20 h. Leakage of grease or oil, or both, is measured, and the condition of the bearing surface is noted at the end of the test.
5. Significance and Use
5.1 This test method differentiates among wheel bearing greases having distinctly different high-temperature leakage characteristics. It is not the equivalent of longtime service tests.
5.2 This test method has proven to be helpful in screening greases with respect to leakage tendencies for automotive wheel bearing applications.
NOTE 1 - It is possible for skilled operators to observe changes in grease characteristics that can occur during the test, such as grease condition. Leakage is reported as a quantitative value, whereas the evaluation of grease condition is subject to differences in personal judgment among operators and cannot be used effectively for quantitative measurements.
