TM 5-3805-280-24-2
Crankshaft, Main Bearings and Flywheel
15
Item
Measurement
Specification
9
Crankshaft Main Bearing Cap
135 Nm (100 lb-ft)
Screws
Crankshaft Rear Main (Thrust)
135 Nm (100 lb-ft)
Bearing Cap Screws
Crankshaft
End Play
0.05--0.25 mm (0.002--0.010 in.)
Flywheel Housing M12 Cap Screws
80 Nm (60 lb-ft)
Flywheel Housing M18 Cap Screws
125 Nm (92 lb-ft)
(Option Code 1418)
Flywheel Housing Seal Bore
Maximum Permissible Run-Out
0.152 mm (0.006 in.)
DPSG,OUO1004,231
1910JUL983/3
CRANKSHAFT AND MAIN BEARING FAILURE ANALYSIS
Misaligned or bent connecting rod.
Scored Main Bearing: (Diagnosis also applies to
Warped or bowed crankshaft.
connecting rod bearing.)
Distorted cylinder block.
Oil starvation.
Broken Main Bearing Caps:
Contaminated oil.
Engine parts failure.
Improper installation.
Excessive heat.
Dirt between bearing and crankshaft journal.
Poor periodic service.
Low oil pressure.
Oil pump failure.
Galled or "Wiped" Bearings:
Fuel in lubricating oil (incomplete combustion).
Cracked, Chipped or Broken Bearings:
Coolant in lubrication system (cracked block, liner
Overspeeding.
seal failure, or leaking water pump seal with plugged
Excessive idling.
hole).
Insufficient bearing oil clearance.
Lugging.
Parts not lubricated prior to engine operation.
Excessive oil clearance.
Wrong bearing size.
Improper installation.
Inconsistent Wear Pattern:
RG,15,DT7461 1914NOV971/1
13-187
