RETAINER 4Z8297 - Caterpillar

Introduction
Use the solution that is identified below, in order to resolve the problem.Problem
Reports have been made of the guide springs failing and the valve lifter assemblies failing on various C9 and C9.3 engines. Note: These failures lead to valve lifter and cam lobe damage requiring extensive repairs.Solution
Update to new part numbers.When making repairs in the field, only use guide springs that do not have a part number stamped in the body.Rework Procedure
Table 1
New Part Number     Part Description     Former Part Number    
453-6003     Guide Spring     304-5260    
384-4171
453-5998     Valve Lifter As     163-2437    
384-4172 Note: Highly recommended that all of the guide springs and all of the valve lifter assemblies be updated to the new parts whenever the cylinder head is removed for any service.Inspect the camshaft lobes, lifter bores, and all other components for any damage or abnormal wear and repair as necessary. Note: The 304-5260 Guide Spring can still be ordered for the 3208 applications. If the 304-5260 Guide Spring is ordered for the C9 and C9.3 applications, the order will be denied. Only use the new part numbers listed above in table 1 for the C9 and C9.3 applications.