It is now well known that the preload and number of rolling elements of an angular contact ball bearing are two important parameters that affect the bearing-induced vibration of a shaft-bearing assembly. Increasing the preload changes the steady state position of the vibration on the non-linear contact-force relation of the bearing, resulting in the shaft mass being supported on stiffer springs. A larger number of rolling elements causes a similar stiffer equivalent spring. The ball set position is another parameter that affects the vibration of the system. These effects have been investigated by different researchers with simulation programs, and their findings are also supported by the experimental evidence of other researchers. In this paper, therefore, a new analytical investigation into the effects of preload, the number of rolling elements and ball set position is made. Analytical results are found to be in good agreement with simulation results.