What is the warranty on sierra marine parts? A leading supplier of marine engines and drive parts for over 35 years, Sierra Marine parts are unconditionally backed by their warranty. That means that the company will pay for shop labor, haul out and towing fees and all related incidental charges should a warranteed part fail.Why choose sierra marine? Renowned for their quality and dependability, Sierra supplies their engine parts to many OEM engine manufacturers and boat builders. A leading supplier of marine engines and drive parts for over 35 years, Sierra Marine parts are unconditionally backed by their warranty.How do i contact sierra? In addition to SONAR Pro, dealers may call 217-324-9428 to discuss any such claim with a SIERRA representative. In order to process all claims quickly and efficiently, the following must be shipped directly to SIERRA via a traceable and insurable method (i.e. UPS, Federal Express, Registered U.S. Mail, etc.):