COVER AS-SOUND SUPPRESSION 5513721 - Caterpillar

3408, 3412 Engines In All ApplicationsDescription of Change: Some of the rocker arm shafts used in valve rocker shaft assemblies for the above engines have oversize (larger than standard size) bores in the ends of the shafts. When the bores are oversize, the standard cup plugs will not fit and special cup plugs must be used. The special cup plugs are available, and can be used in any shafts where the standard plugs are loose in the bores.Adaptable To: The L1022 Special Cup Plug (16.84 0.03 mm - .663 .001" diameter) can be used in place of the 5B1866 Cup Plug (16.18 mm - .637" diameter) in 4N839, 4N1106, or 4N1108 Valve Rocker Shaft Assemblies when necessary.