TM 5-3810-300-24&P-3
Main Bearings 1.3.4
4. With the lower main bearing shells installed in
the bearing caps, apply a small quantity of
International Compound No. 2, or equivalent, to
the bolt or stud and nut threads and the bolt
head (or nut) contact area. Install the bearing
caps and draw the bolts (or nuts) up snug. Then
rap the caps sharply with a soft hammer to seat
them properly and tighten the bolts uniformly to
180-190 lb-ft torque. If studs and nuts are used,
tighten the nuts to 155-185 lb-ft torque (cast iron
block) or 120-140 lb-ft torque (aluminum block).
Do not exceed the specified torque.
NOTE:
If the bearings have been
installed properly, the crankshaft will turn
freely with all of the main bearing cap
Fig. 9. Main Bearing Cap Marking
bolts drawn to the specified torque.
2. Install the lower main bearing shell so that the
5. Check the crankshaft end play as outlined under
tang on the bearing fits into the groove in the
Install Crankshaft in Section 1.3.
bearing cap.
6. Install the lubricating oil pump and the oil inlet
3. Assemble the crankshaft thrust washers (Fig. 8)
and outlet pipe assemblies.
before installing the rear main bearing cap.
Clear both halves of each thrust washer
NOTE: If shims were used between the
carefully and remove any burrs from the washer
pump and the bearing caps, install them
seats - the slightest burr or particle of dirt may
in their original positions. Then check oil
decrease the clearance between the washers
pump gear clearance (Section 4.1).
and the crankshaft beyond the specified limit.
Slide the upper halves of the thrust washers into
7. Install the oil pan, using a new gasket.
place. Then assemble the lower halves over the
dowel pins in the bearing cap.
8. Fill the crankcase to the proper level on the
dipstick with heavy-duty lubricating oil of the
NOTE: The main bearing caps are
recommended grade and viscosity (refer to
bored in position and stamped 1, 2, 3,
Lubricating Oil Specifications in Section 13.3).
etc. (Fig. 9). They must be installed in
their original positions with the marked
9. After installing new bearing shells, operate the
side of each cap toward the blower side
engine on a run-in schedule as outlined in
of the cylinder block.
Section 13.2.1.
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