The impact of spindle condition on machining performances is arduous to perceive since very long periods must be considered. This paper proposes an experimental approach based on accurate characterizations of the dynamic behavior for different spindle conditions (repaired or damaged). The Frequency Response Functions of the spindle were obtained for different spindle conditions and speeds, through an electromagnetic excitation device. The main failure modes of HSM spindle were then identified and modeled. Their effects on FRF were simulated and general conclusions were obtained concerning their impacts on spindle dynamics. Lastly, cutting tests reveal the impact of spindle condition on stability lobe diagrams.