A dynamic model is developed in order to simulate the vibrations of rolling ball bearings caused by local surface defects on bearing raceways. In this model, each bearing element (i.e. inner ring, outer ring and rolling balls) has 6 degrees of freedom to completely describe its dynamic characteristics in three-dimensional space. The model incorporates gyroscopic effects, centrifugal forces, and lubrication tractions between bearing elements. Additionally, the vibration effect of local surface defects in raceways is modeled through surface profile changes. The obtained equations of motion are solved numerically by using a fourth order scheme with a step-changing criterion. Vibration responses of the bearing are analyzed in domains of both time and frequency. Because lubrication tractive forces are considered, characteristic defect frequencies calculated by the dynamic model are less different from the ones calculated on the assumption of pure rolling. The proposed model contains the three dimensional motions of each bearing element, relative slippage, lubrication effects, and local surface defects, which is more comprehensive, effective, and practical than studies currently available in literature.