TM 5-4320-300-14
6-10. PISTONS AND CONNECTING RODS (CONT)
Location/Item
Action
Remarks
NOTE
If undersize bearing shells were installed at an earlier date, the standard
minimum worn thickness dimension will not be accurate. Compare dimen-
sions of undersize bearings to the chart below.
Bearing Size
New Bearing Thickness
Minimum Worn Thickness
inch
(mm)
inch
(mm)
inch
(mm)
Standard
0.1245/0.1250
(3.1623/3.175)
0.1230
(3.1242)
Undersize
0.002
(0.0508)
0.1255/0.1260
(3.1877/3.2004)
0.1240
(3.1496)
0.010
(0.254)
0.1295/0.1300
(3.2893/3.302)
0.1280
(3.2512)
0.020
(0.508)
0.1345/0.1350
(3.4163/3.429)
0.1330
(3.3782)
0.030
(0.762)
0.1395/0.1400
(3.5433/3.556)
0.1380
(3.5052)
17. Crankshaft
Before installing bearings, inspect crankshaft
in accordance with paragraph 6-11.
WARNING
Compressed air used for cleaning shall not exceed 100 psi (690 kPa). Use
goggles or face shield for eye protection. Do not direct airstream against
skin.
18. Connecting
Blow compressed air through spray
nozzle
rod spray
and inspect it for blockage.
nozzle
19. Piston skirt
Measure each piston skirt diameter length-
Piston skirt diameter
diameter
wise and crosswise of the piston pin bore.
measurement should
Piston skirt must measure between 3.8699
be taken at a room
and 3.8721 inches (98.2955 and 98.3513
temperature of 70°F
mm).
21 C).
20. Piston out-
Measure piston out-of-round and taper.
of-round
The out-of-round and taper must not ex-
and taper
ceed 0.0005 inch (0.0127 mm).
6-83
