Figure 3-57. Comparison of used pistons.

Figure 3-57. Comparison of used pistons.

worn excessively, replace the bushings or piston

(d) Examine the inside of the piston closely

for cracks across the struts and discard piston if

assemblies. Also inspect and measure the piston

such cracks are present.

pin. The standard inside diameter of bushings in a

piston is 1.3775-1.3780 inches and the standard

(e) Inspect the top of the piston crown for

burned spots or other indications of overheating

outside diameter of the piston pin is 1.3746 inch-

1.3750; thus, the standard clearance between the

such as carbon formation on the underside of the

p i s t o n pin and bushing, in a piston is 0.0025-

piston.

0.0034 inch with a maximum allowable wear limit

(f) Inspect the piston rings for free fit in the

grooves and side clearance.

of 0.010 inch. Ream new piston bushings as

illustrated in figure 3-58.

(g) Inspect and measure the inside diameter

of the piston pin bushings in each piston, and, if