The piston pin to piston clearance should not exceed
NOTE
0.004 inch. The specified piston pin to rod bearing
clearance is 0.0009 to 0.0019 inches. Replace bearing
When reassembling pistons and
and/or pin when clearance exceeds 0.004 inch. Piston
rods, be sure the V-marks on piston
pin bearing bore is 1.7009 to 7.7015 inches new.
and block aline when the rod part
number faces toward the front of
(4) Inspect connecting rod for evidence of bend or
block, and rod cylinder number faces
misalignment. If bent, rod must be replaced.
left side of engine. At installation,
(5) Inspect connecting rod bearings for scoring,
torque rod bolt nuts to 85 ft-lb. If
damage or wear. The specified rod bearing clearance is
necessary tighten to next slot in nut
between 0.0032 and 0.0061 inches.
Replace the
to install a new cotterpin.
bearings when clearance exceeds 0.009 inch.
(1) Reassemble by reversing procedures in
c. Reassembly and Installation.
steps (7) and (8) of a above.
(2) Install by reversing procedures in steps (1)
through (6) in a above.
Section XVII. CRANKSHAFT AND MAIN BEARINGS
(6) Remove capnuts (1) from the seven main
3-59. General
bearing caps (7), then remove bearing caps.
(7) Use a suitable sling and lifting device to
a. Engine Model 687C-18-ES. The crankshaft gear
remove crankshaft (14) from crankcase.
is installed on rear end of crankshaft and located
(8) Install crankshaft by reversing procedures in
(positioned) by two large drive dowel pins, which extends
steps (1) through (7) above.
through the gear, and locates flywheel as well. One of
these dowel pins is offset slightly to prevent incorrect
b. Disassembly and Reassembly.
assembly. Crankshaft thrust is taken on rear main
journal. End clearance of the crankshaft must not
(1) Remove upper main bearings (9, fig. 3-65)
exceed 0.020 inch. Bearing caps (7, fig. 3-49) should
from crankcase. Tag each one so that it can be
not be filed or shimmed. The bearing halves are held in
reinstalled in its same position.
place by tangs at split line. Both halves of the main
(2) Remove thrustwasher (17) from crankshaft
bearings allow continuous lubrication. Main bearing caps
(8).
are numbered from front to rear, and must be returned to
(3) Reassemble by reversing procedures in
same place from which removed, with numbered side
steps (1) and (2) above.
toward camshaft.
c. Cleaning, Inspection, and Repair.
b. Engine Model D333TA. The crankshaft gear is
installed on front end of crankshaft and is located by key,
(1) Clean all parts and dry thoroughly before
with a seal between gear and damper. There are seven
inspection or reassembly.
main bearings. They are steel backed aluminum lined
(2) Inspect main bearings and crankshaft
precision type. Tabs are punched outward on bearing
journals for wear or other damage. Main bearing oil
half at parting line, and fit into recesses in block and
clearance must not exceed 0.008 inch.
bearing cap to prevent it rotating. The crankshaft thrust
(3) Inspect mounting hardware for burs or other
is taken on flange of lower half of rear main bearing.
defect. Replace defective mounting hardware.
The upper half of rear main bearing does not have a
flange.
3-61. Crankshaft and Main Bearings (Engine ModeI
D333TA)
3-60. Crankshaft and Main Bearings (Engine Model
a. Removal and Installation.
687C-18ES)
(1) Remove flywheel housing (para 3-41).
a. Removal and Installation.
(2) Remove front cover (paras 3-31).
(1) Remove engine front cover (para 3-48).
(2) Remove flywheel housing (para -40).
(3) Remove oil pan (para 3-4).
(4) Remove oil pump (para 3-45).
(5) Remove capnuts (8, fig. 3-49), caps (11)
from the six rods, then push rods and pistons up in
cylinder.
AGO 20051A
3-76
