TM 5-4320-302-14
6-20. CRANKSHAFT ASSEMBLY (CONT)
Location/Item
Action
Remarks
MAIN BEARING
MAIN BEARING SUPPORT
SUPPORT BORE
WALL THICKNESS
(NORMAL AND UNDERSIZES)
(NORMAL AND OVERSIZES)
MAIN BEARING
inches
inches
SUPPORT
(millimeters)
(millimeters)
2.3638 to 2.3655
0.1170 to 0.1175
Normal
(60.040 to 60.083)
(2.973 to 2.985)
2.3441 to 2.3458
0.1269-to 0.1274
First undersize
(59.540 to 59.583)
(3.223 to 3.235)
2.3244 to 2.3261
0.1367 to 0.1372
Second undersize
(59.040 to 59.083)
(3.473 to 3.485)
2.3047 to 2.3064
0.1466 to 0.1470
Third undersize
(58.540 to 58.583)
(3.723 to 3.735)
35. Radial
Replacement of main bearing supports depends
clearance
on the diameter of the crankshaft center bear-
ing journal. Measure diameter and determine
radial clearance by subtracting journal diameter
from bearing support bore. Clearance should be
0.0020 to 0.0044 inch (0.05 to 0.112 mm).
Maximum allowable clearance is 0.0118 inch
(0.3 mm). If radial clearance is not within these
tolerance limits, recheck main bearing supports,
main bearing bracket, and/or crankshaft. Replace
components in that order until clearance is within
tolerance limits.
36. Side clearance
Measure width of crankshaft center bearing
journal. Measure width of main bearing bracket
at bearing bore. Determine side clearance by sub-
tracting bearing bracket width from bearing
journal width. Side clearance should be 0.0079
to 0.0157 inch (0.200 to 0.400 mm). Maximum
allowable clearance is 0.0197 inch (0.5 mm). If
side clearance is not within these tolerance
limits, recheck main bearing bracket and crank-
shaft center bearing journal. Replace in that order
until side clearance is within tolerance limits.
6-181
