CYLINDER HEAD AS 4P6571 - Caterpillar

3304 Industrial and Marine Engines;
3306 Industrial, Marine and Truck Engines;
D4D, D5, D5B, D6C, D6D, D7G, 814, 627B and 627B Push-Pull Tractors;
815 and 816 Compactors;
920, 930, 941, 950, 951B, 951C, 955K, 955L, 966C, 977K, 977L and 980B Loaders;
518 and 528 Skidders;
12G, 14G, 120G, 130G, 140G and 120B Motor Graders;
561C, 561D, 571G and 572G Pipelayers;
215, 225 and 235 Excavators;
627B, 637D, 627B and 637D P.P. ScrapersDescription of Change: The oil inlet hole in the rocker arm shafts for the above models is now larger in diameter. This permits more oil to get to the rocker arm bearings to prevent possible failures. Also, the brackets for the rocker arm shaft are machined flat on top to prevent possible oil leakage between the washers of the bolts and the brackets.Adaptable As: Direct replacement. The part numbers of the rocker arm assemblies did not change. If desired, the oil inlet holes in the earlier rocker arm shafts can be drilled to a larger diameter. Formerly, the diameter size was .062" (1.57 mm). Now the diameter size is .094" (2.38 mm). Care must be taken if the rocker arm shaft is drilled, the shaft is made of a hardened steel.
It is more practical to install a new rocker arm shaft assembly, especially if bearing failures have been a problem.