TM 9-6115-604-34
NAVFAC P-8-633-34
(x) Using honing machine MIL-H-45583, size the new piston pin bushing (13, Figure 9-24) to an inside diameter of 2.4010
to 2.4015 inches (60.985 to 60.998 mm).
WARNING
Dry cleaning solvent PD-680, Type III, or equivalent, is flammable and moderately toxic to the
skin, eyes, and respiratory tract. Assure adequate ventilation. Skin, eye, and respiratory
protection Is required to avoid Injury to personnel.
WARNING
Compressed air used for cleaning or drying can create airborne particles that may enter the
eyes. Pressure shall not exceed 30 psi (207 kPa). Wearing of goggles Is required to avoid
Injury to personnel.
(y)
Clean the bushing and oil passage in the connecting rod thoroughly, using dry cleaning solvent P-D-680,
Type 11, or equivalent, and blow dry with compressed air.
(z)
Re-check the connecting rod alignment in accordance with step (9), above.
(11)
Check the bolts and dowels as follows:
(a)
Check for bent or distorted bolts. The head of the connecting rod bolt (1, Figure 9-24) must rest squarely
on the milled surface of the cap (3), (see step (1), above. Replace bent or distorted connecting rod bolts.
(b)
If the connecting rod bolts (1) have been tightened excessively, they may be permanently stretched in the
area indicated in Figure 9-29. Replace any bolt if the smallest diameter is less than 0.600 inch (15.24
mm).
(c)
Replace any connecting rod bolts (1, Figure 9-24) that have distorted threads.
(d)
Remove and discard the dowels (12), if damaged. Check the piston pin (9) outside diameter with a
micrometer. Pins shall be replaced if they are out-of-round more than 0.001 inch (0.03 mm), or worn
smaller than the minimum diameter given in Table 14.
(12)
Check the piston pin (9) outside diameter with a micrometer. Pins shall be replaced if they are out-of-round more
than 0.001 inch (0.03 mm), or worn smaller than the minimum diameter given in Table 1-4.
(13)
Inspect the pistons (10) as follows:
(a)
Visually inspect the piston for signs of erosion, broken ring lands, visible cracks, or severe scoring.
Replace defective pistons.
(b)
Check the piston ring grooves for wear using wear gage ST-560.If the gage shoulder touches the ring
groove lands, replace the piston.
NOTE
Because aluminum pistons have a high coefficient of expansion, all measurements shall be
taken at a stabilized piston temperature of 70°F (21°C).
(c)
Measure the piston pin bore on both sides of the piston with an inside micrometer. Replace the piston if
the pin bore on either side is over the allowable limits given in Table 1-4.
(d)
Using an outside micrometer, measure the piston skirt at 90 degrees to the piston pin bore. Replace the
piston if the skirt diameter is under the limits given in Table 1-4.
(e)
Inspect the piston for cracks using dye penetrant MIL-1-25135 accordance with MIL-1K66. Replace any
defective pistons.
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