3-40.1. PISTON - MAINTENANCE INSTRUCTIONS (Cont).
Inspect and measure the piston pin bushings. The
piston pin-to-bushing clearance with new parts is
.0025 to .0034 inch (0.0064 to 0.0086 cm). A maximum
clearance of .010 inch (0.0001 cm) is allowable with
worn parts. The piston pin bushings in the connect-
ing rod are covered in paragraph 3-40.2 .
Other factors that may contribute to piston failure
include oil leakage into the air box, oil pull-over
from the air cleaner, dribbling injectors, combus-
tion blow-by and low oil pressure (dilution of the
Do not remove the bushings from the piston. They are not serviced separately.
Measure the piston skirt
diameter lengthwise and
crosswise of the piston
pin bore. Measurements
should be taken at room
temperature (70 or
21 ). The taper and
out-of-round must not
exceed .0005 inch. Refer
to Table for piston