Automotive companies have tried to replace metals with plastic materials in order to reduce weight, cost and noise. This trend can be seen not only in interior and exterior parts but also in underhood parts of automobile. The representative example of replacing metals in underhood parts in power steering pump pulley. And we use phenolic engineering thermosets as substitute materials.This paper presents mechanical properties of phenolic engineering thermosets such as strength, flexural modulus, creep resistance, fluid resistance compared with nylon materials at high temperatures. Furthermore, in this study, we review a design-optimization process by Finite Element Analysis and tortional and static load test for insert. And then this paper shows how to validate phenolic power steering pump pulley as an application part of automotive.