What can mechanics do with this tool?
A. Clean auto parts
B. Pack wheel bearings
C. Recondition dust covers
D. Recondition automotive seals
Answer: B, Pack wheel bearings
A wheel bearing is a set of steel balls held together by a metal ring called a race. They help wheels spin fast with as little friction as possible.
Heat caused by lack of lubrication can destroy a wheel bearing. Water that penetrates a sealed bearing will also destroy it. In these cases you will need to have new bearings packed inside a hub.
When wheel bearings go out your car will make really loud noise. The noise will be faint and gradually get louder as they continue to get more worn.
Like all car noises, get it checked out sooner than later is the best policy.