ENGINE
DISASSEMBLY AND ASSEMBLY
TM 5-3805-263-14&P-2
CRANKSHAFT MAIN BEARINGS
REMOVE AND INSTALL CRANKSHAFT MAIN
BEARINGS
Tools Needed
A
B
C
2P5518
Main Bearing Removal Tool 1
Plastigage
*
8S2328
Dial Test Indicator Group
1
start by:
a) remove oil pump
b) remove oil pan plate
1. Remove the No. 1, 3 and 5 main bearing caps
(1). Remove the crankshaft thrust bearing
from the No. 5 main bearing.
2. Remove the lower half of the main bearing
from the main bearing caps.
CAUTION
If the crankshaft is turned in the wrong direc-
tion, the tab on bearing will be pushed between
the crankshaft and bearing area in block which
can cause damage to the block or crankshaft.
3. Install tool (A) in the oil hole in the crankshaft
journal and remove the upper half of the main
bearing as the crankshaft is turned and the
main bearing is moved out of the cylinder
block.
NOTE: Install the main bearings dry when the clear-
ance checks are made. Put clean engine oil on the
main bearings for final assembly.
CAUTION
Make sure the upper and lower halves of the
main bearings are installed so the bearing tabs
fit into the notch in cylinder block and the main
bearing caps.
4. Install new lower half of main bearings (2) in
the main bearing caps. Use tool (A) and install
the upper half of the main bearings in the
cylinder block.
5. Put clean oil on the thrust bearing and install a
new thrust bearing for the No. 5 main bearing.
Install the thrust bearing with the identifica-
tion "BLOCK SIDE" toward the cylinder
block and the tabs on the thrust bearings in the
machined area in the cylinder block. The tabs
will not let the thrust bearing be installed back-
ward.
NOTE: When the bearing clearance is checked and
the engine is in a vertical position, such as in the
vehicle, the crankshaft will have to be lifted up and
held against the upper halves of the main bearings to
get a correct measurement with the Plastigage. The
Plastigage will not hold the weight of the crankshaft
and give a correct indication. If the engine is in a
horizontal position, it is not necessary to hold the
crankshaft up. Do not turn the crankshaft when the
Plastigage is in position to check clearances.
6. Check the main bearing clearances with Plasti-
gage (B) as follows:
a) Put a piece of Plastigage (B) on the surface
of the lower half of the main bearing.
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