this rate build up controls noise vibration and harshness associated with for example the vehicle environment the elastomer is preferably mold bonded to the inner surface 24 although it will be appreciated that other bonding arrangements such as an adhesive bond can be used without departing from the scope and intent of the present invention likewise an inner diameter portion 34 of the isolator is secured to a shaft assembly 40 which is preferably comprised of first and second components 42 44 the isolator is secured to a first or outer surface 46 of the first component and again is illustrated as being mold bonded thereto as will become more apparent below the first component 42 in this embodiment is defined by first and second portions 42 a 42 b that are separated and have outer surfaces 46 a 46 b that are bonded to the isolator respectively inner facing surfaces 48 a 48 b of the first component are separated along a split plane and slidably engage the second component 44 of the shaft assembly as perhaps best illustrated in fig2 and fig4 7 the first and second components 42 44 of the shaft assembly have mating keyed configurations that provide for slidable insertion of the second component into a cavity defined along the split plane between the first and second portions 42 a 42 b of the first component and likewise resist relative movement between the first and second component in other directions this mating keyed configuration provides an interlocking feature that allows the separate components here three separate pieces to merge and function as a single component for example as illustrated in fig2 the first and second portions 42 a 42 b of the first component have dove tailed keyways 60 formed on opposite.