1.
Capscrew (8 rqr)
11.
Crankshaft pulley
2.
Lock (3 rqr)
12.
Retainer washer
3.
Bearing
13.
Capscrew (2 rqr)
4
Flywheel
14.
Lockwire
5.
Retainer ring (2 rqr)
15.
Capscrew
6.
Crankshaft gear
16.
Lower main bearing (7 rqr)
7.
Dowel pin
17
Thrustwasher
8.
Crankshaft
18.
Capscrew (4rqr)
9.
Upper main bearing (7 rqr)
19.
Flywheel dowel pin (2 rqr)
10
Key
Figure 3-65. Crankshaft and flywheel for engine model 687C018-ES,erxploded
(3) Remove oil pan and plate (paras 3-44).
Torque main bearing cap nuts to 155
(4) Remove connecting rod caps (para 3-58) and
ft lb, and pulley retaining bolt to
push pistons up into cylinders and out of way.
between 210 and 250 ft lb.
(5) Remove 14 cotterpins (1, fig. 3-66), nuts (2)
and seven main bearing caps (3, 4, and 5) from studs on
b. Cleaning, Inspection, and Repair.
crankcase (6). Remove the rear lower flanged bearing
half (7) and six lower bearing halves (8) from bearing
(1) Clean all parts and dry thoroughly before
caps.
inspection or installation.
(2) Inspect crankshaft for cracks and scored or
NOTE
worn journals. If the crankshaft is scored; has a main
journal worn in excess of 0.005 inch; has a rod journal
If bearings are not to be replaced,
worn in excess of 0.004 inch, or has a rod journal out-of-
keep halves together with their cap,
round in excess of 0.002 inch, it will be rehabilitated (c
below) or replaced. Main journal diameter is 3.499 to
marked for reinstallation in same
3.500 inch and rod journal diameter is 2.999 to 3.000
place from which removed.
inch, when new. A cracked or bent crankshaft will be
replaced.
(6) Remove crankshaft gear (9) and key (10)
(3) Inspect main bearings for scoring, damage,
from crankshaft (11).
or wear. Main bearings have a specified clearance of
(7) Use suitable sling and lifting device and
between 0.0030 and 0.0059 inch. Replace bearings in
remove crankshaft (11) from crankcase (6).
sets of seven when clearance on any one bearing
(8) Remove seven upper bearing halves (12)
measures in excess of 0.008 inch. Replace scored or
from crankcase (6).
damaged bearings.
(9) Remove studs (18 and 14) as required.
(4) The specified crankshaft end clearance is
(10) Install main bearings and crankshaft by
between 0.011 and 0.018 inches. Replace the thrust
reversing procedure in steps (1) through (9) above.
bearing (rear lower flanged half (7) figure 3-66), when
end clearance measures in excess of 0.027 inch, then
NOTE
recheck
the
clearance.
3-77
