The pulleys of an automotive front engine accessory drive are driven in rotation by a poly-V belt itself driven by the crankshaft pulley. This driving pulley is often used as a torsional vibration damper (TVD) for the crankshaft. Three elements compose the pulley: the hub, a rubber ring and an inertia steel ring with v-ribs on its outer diameter. Although the crankshaft torsional vibrations are dampen, they are transmitted to the belt transmission and therefore to the driven accessories. Hence, recent developments have conducted to add a decoupling function to these pulleys. The decoupling is realized by an other rubber ring. The TVD pulley components are designed in order to dampen crankshaft vibrations over a given frequency range, i.e. stiffness and damping characteristics are determined for the rubber ring. These expected characteristics have to be checked after manufacturing for product certification but also to give some real measured data input for simulation models. An experimental characterization method is presented and discussed for the determination of the stiffness and damping coefficients of the rubber rings used in such pulley. The test rig developed is temperature controlled in order to show the influence of the temperature.