VALVE TRAIN - CAMSHAFT, TAPPETS & PUSH RODS
Design changes to improve initial lubrication to valve
train components have been made by revising the rocker
shafts and rocker arms on 400 Series engines. Rocker
shafts were revised by drilling 3.1750 mm (.125 in.)
diameter holes through the shaft while the rocker arm
assembly oil hole was relocated to a vertical position.
Figures 9 and 10 illustrate the displaced and new
Engines built with and after the following serial numbers
incorporate the new rocker arm and rocker arm shaft:
Displaced shafts must NOT be used with new
New shaft may be used with EITHER new or
displaced rocker arms.
Figure 9. - Rocker Arm
Figure 10. - Rocker Arm ShaftCG-6459
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