Cummins ISBe/ISDe Idler Pulley 4991240 Parts Catalogue Ref No. Part Name Part No. Required 1 Idler Pulley 4991240 1 Above is the introduction of the Cummins 4991240 Idler Pulley, while if you need any other Cummins spare parts or complete Cummins engine, Please further consult our sales.