A technique facilitates the reduction of vibration in a variety of devices which have rotating components. According to an embodiment, a system may combine a shaft, a rotor mounted along the shaft for rotation with the shaft, and a vibration reduction system. The vibration reduction system incorporates the use of a key and keyway in a manner which helps balance the rotor, thus reducing vibration during operation. In some applications, the vibration reduction system is able to reduce eccentric positioning of the rotor on the shaft due to, for example, assembly clearances.