TM 5-4320-300-14
6-11. CRANKSHAFT AND FLYWHEEL (CONT))
Location/Item
Action
Remarks
32. Bearing
Consult the bearing size chart below and select
selection
the proper bearing for new journal dimensions.
NOTE
The 0.002 inch (0.0508 mm) undersize bearings are used only to compen-
sate for slight wear on crankshafts on which regrinding is unnecessary.
Connecting Rod
Main Bearing
Bearing Size
Journal Diameter
Journal Diameter
inch
(mm)
inch
(mm)
inch
(mm)
Standard
2.499/2.500
(63.475/63.500)
2.999/3.000
(76.175/76.200)
Undersize
0.002
(0.0508)
2.497/2.498
(63.424/63.449)
2.996/2.998
(76.124/76.149)
0.010
(0.254)
2.489/2.490
(63.221/63.246)
2.989/2.990
(75.921/75.946)
0.020
(0.508)
2.479/2.480
(62.967/62.992)
2.979/2.980
(75.667/75.692)
0.030
(0.762)
2.469/2.470
(62.713/62.738)
2.969/2.970
(75.413/75.438)
33. Bearing
Stone edges of all oil holes in journal surfaces to
journal
provide a smooth radius of approximately 3/32
oil holes
inch (2.381 mm).
34. Ground
Polish ground surfaces to an 8 to 12 RMS
surfaces
finish.
35. Crankshaft
Measure. If worn or grooved
thrust
excessively, regrind and
surfaces
polish surfaces. Leave a
0.130 to 0.160 inch
(3.302 to 4.064 mm)
radius on crankshaft
between each thrust
surface and bearing
journal.
36. Crankshaft
To locate minute cracks due to grinding opera-
tion, reinspect crankshaft using MIL-1-6868
Magnetic Particle Inspection.
6-103
