Servicing your wheel bearings is an important part of your annual maintenance routine.
Wheel bearings should be serviced at a minimum every second year or every 12,000 miles ( 20,000 km), whichever comes first. Servicing your wheel bearings includes removing the wheel hubs and bearing, cleaning the bearings and inspecting the bearings and races for wear, damage or heat, repacking using a high quality synthetic bearing grease and reassemble using a new seal and cotter pin, making sure the bearing is adjusting correctly. Grease contaminated with dirt or water, or improper bearing adjustment are the largest factors in bearing failure. The use of EZ Lube axles or Bearing Buddies is not recommended because the bearings and races are not being inspected, any contaminates are not being removed, just clean grease is being added which will soon be contaminated by the old grease, also bearing adjustment is not being checked.
Typically well maintained bearings will last many years with cleaning and repacking with high quality synthetic bearing grease is all that is needed, but if you find any wear or damage you need to replace the wheel bearing and race as a set, do not put a new bearing in an old race, rapid bearing failure will be the result. When replacing bearings use high quality bearings like Timken or SKF, avoid no-name or off brands as they may be low quality, there will be numbers etched on both the edge of the bearing and race, use these numbers to match the new bearing set.
The following video shows the correct way to service your wheel bearings