TM 5-4320-302-14
6-18. CRANKSHAFT ASSEMBLY (CONT)
Location/Item
Action
Remarks
b. Normal main bearing journal diameter should be
2.5185 to 2.5193 inches (63.971 to 63.990 mm).
If any measurement is outside the specified
limits, the crankshaft must be replaced. How-
ever, if journals are evenly worn, not out-of-
round, and crankpin diameters are within speci-
fied limits, only main bearing bushes need be
replaced.
c.
Replace bearing bushes in accordance with
paragraph 6-12. Make sure that main bearing
bush radial clearance does not exceed 0.0024
to 0.0118 inch (0.06 to 0.3 mm). If specified
limits are exceeded, the crankshaft must be
replaced.
d.
If measurements at points 1 and 2 differ by
more than 0.0028 inch (0.07 mm) and/or one
set is outside the specified limits, the journal
is worn into a conical shape and crankshaft
must be replaced. If measurements along axis
A and B differ by more than 0.0028 inch
(0.07 mm) and/or one set is outside the speci-
fied limits, the journals are worn into an oval
shape and crankshaft must be replaced. For
both of these out-of-round conditions, also
check connecting rods, pistons, cylinders, and
main bearing bushes for unusual wear. Journal
width measured at point 3 should be 1.3130 to
1.3189 inches (33.350 to 33.500 mm). Fillet
radius measurement should be 0.1693 to
0.1772 inch (4.30 to 4.50 mm). If either
measurement is outside specified limits, the
crankshaft-must be replaced.
11. Replacement
If the crankshaft must be replaced, the following
crankshaft
main bearing journal diameter normal and
main bearing
undersizes are available:
journals
6-147
