Lubes major questions wheel bearing grease tests

ExxonMobil researchers consider updating motors used for tests to bring specs up to date.

Wheel Hub

Wheel hub assembly Image: Commons

ExxonMobil's concern focuses on the High-Temperature Wheel Bearing Test, according to a recent online post in Fuels and Lubes.

The test is critical to estimating vehicle front wheel bearing lifespans but, according to the lubes giant, the test itself may be past its sell-by date.

The issue apparently focuses on the ASTM D3527 test, used in many existing grease specifications but set up back in 1976.  Automotive design has moved on significantly since then, not least because the test is based on a hub design no longer used on modern cars.

The biggest challenge, according to Exxon's specialists, is in the selection of the electric motors used to run the test rather than the bearings used - the former being less consistent than the latter.  And, because the test remains crucial for the automotive grease industry, an updated solution needs to be found.

According to the report, the Exxon team is experimenting with new, more reliable and controllable motors which are showing positive results in test repeatability.  The company recently shared its finding with ASTM International - the organisation responsible for setting the standard.  ASTM is keen to find new methods of testing precision, not least because it recently agreed to extend the D3527 test by a further five years.