WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Identifying Cracked Inner Race
Courtesy of GENERAL MOTORS CORP.
Cracked race due to improper fit, cocking, or poor bearing seats. Replace the bearing. Correct bearing seats.