TM 5-4320-302-14
6-18. CRANKSHAFT ASSEMBLY (CONT)
Location/Item
Action
Remarks
c.
Replace main bearing supports in accordance
with paragraph 6-20. Make sure that main
bearing support radial clearance does not ex-
ceed 0.0020 to 0.0118 inch (0.05 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 specified
limits, the journal is worn into an oval shape
and crankshaft must be replaced. For both
these out-of-round conditions, also check con-
necting rods, pistons, cylinders, main bearing
bushes, and main bearing supports for unusual
wear. Journal width measured at point 3 should
be 1.5709 to 1.5787 inches (39.900 to 40.100
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.
13. Replacement
If the crankshaft must be replaced, the follow-
crankshaft
ing center bearing journal diameter normal and
center bearing
undersizes are available:
journals
JOURNAL DIAMETER
CENTER BEARING JOURNALS
inches
NORMAL AND UNDERSIZES
(millimeters)
2.3611 to 2.3618
Normal
(59.971 to 59.990)
2.3414 to 2.3421
First undersize
(59.471 to 59.490)
2.3217 to 2.3224
Second undersize
(58.971 to 58.990)
2.3020 to 2.3028
Third undersize
(58.471 to 58.490)
6-149
