Good used, machine shop inspected and polished Mercedes OM904 Crankshaft. Part Number: 90412 Machine shop performed the following: - Run brush down oil hole passages - Jet wash crankshaft - Checked straightness - Mag crankshaft for cracks - Setup crankshaft in machine & Polish Rod and Main Bearings - Rust Proof spray crankshaft and bag 30 day guarantee for swap or refund