TM 5-3810-295-34
(4) Check crankshaft for out-of-round condition.
faces of cap must always rest on mating portion of
Crankshaft shall be replaced if main bearing or
block to prevent distortion during tightening. Caps
crankpin journals are worn out-of-round more than
must have an interface fit to block of 0.000-0.0025
0.002 inch.
inch. Replace caps if these requirements cannot be
(5) Inspect crankshaft journals and thrust flange
met.
at rear main bearing. If surfaces are scored or
(7) Check main bearing bore as follows:
scratched, crankshaft should be replaced.
(a) Assemble main bearing caps to block in
14-37. Repair
operating position. Tighten screws to 150-160 ft-lb
Repair the cylinder block as necessary per the methods
(203.4 216.9 N m), advance to 340--50 (461---475
described immediately below if block is to be reused.
N. m). Loosen to no tension, tighten 85-90 (115.2
a. Replace camshaft bushing with a camshaft
122.0 N -m), and advance to 170-180 ft-lb (230.5-
bushing driver kit or equivalent. Locate new bushings on
244.0 N. m).
drive mandrel, align oil holes in bushings and block,
(8) Inspect all block water passages to insure they
and install.
are open. Check for eroded water holes which may pre-
b. Replace main bearing caps as follows:
vent proper seating of head gasket or grommet re-
(1) Replacement main bearing caps have 0.003-
tainers. Water holes not eroded more than one-six-
inch material in bore and 0.0045-inch excess in length.
teenth of an inch from edge of hole can be sleeved.
New rear replacement cap does not have cap-to-block
(9) Inspect tappet bores with an inside
dowel holes and must be machined to block width.
micrometer. If injector bore exceeds 1.4035 inches or
(2) Machine an equal amount of material from
valve bore exceeds 1.1035 inches or they are out-of-
each end of semi-finished cap to provide 0.001--0.003-
round more than 0.0015 inch, block must be replaced.
inch interference fit in block.
(10) Inspect cylinder liners for cracks under the
(3) If cap is a rear cap, remove locating dowels
top flange, at bottom of liner, or above seal ring groove.
from block. Locate and machine cap so thrust faces of
Discard any liner with excessive corrosion or erosion
cap and block are flush. Use Prussian Blue on block
and one-sixteenth of an inch deep or more, or if dents
surface to locate dowel holes in cap. Install screws and
or fretting of liner flange cannot be removed by lap-
torque to 55-lb-ft (74.6 N. m). Remove cap and drill
ping. Inside diameter of the liner shall not exceed 5.505
dowel holes. Reinstall cap and ream dowel holes to
inches at 60-70F.
smallest permissible oversize. Install dowel in block.
(11) Check block height from head surface to main
(4) If thrust bearing locating dowel must be
bearing bore centerline. Distance must be greater than
replaced, install new dowel. Dowel must have 0.090--
13.143 inches.
0.105-inch protrusion from machined area of bearing
NOTE
cap mating surface.
When measuring, block must be unsupported
(5) Install all caps on block and ream bore to
and on a flat surface.
4.062--4.063 inches.
(12) Distance from head surface to main bearing
C Sleeve eroded water holes as described in the
bore centerline must not vary more than 0.002 inch in
following steps.
each 20 inches of block length. Heat surface flatness
(1) Water holes to be sleeved must be free of any
must not vary over 0.0005 inch for each eight inches of
erosion, scratches or blemishes which are more than
surface on each bank. Waviness must not exceed
0.003 inch deep in the area 1e6 to M,2 inch from their
0.0004 inch in depth per square inch of area. If these
edges.
requirements are not met, top surface shall be
(2) Using a water hole counterboring tool or
refinished.
equivalent, enlarge holes for sleeve.
NOTE
(3) Align sleeve in top of water passage hole, and
If an excess of 0.010 inch of material must be
with a suitable driver and hammer drive sleeve in until
removed, block cannot be used.
it bottoms. Sleeve will protrude above surface of block.
e. Inspect crankshaft as follows:
(4) If block is not to be resurfaced, file bushing
(1) Inspect crankshaft gear for chipping, cracks,
flush with top of block, using a wide, flat file.
or broken teeth. If any damage is observed replace
d. Refinish top-surface of block as follows:
gear.
(1) Place block on main bearing pads, remove
(2) Inspect crankshaft visually for scratches,
ring dowels from head surface.
nicks, cracks and obvious wear patterns.
(2) With either a milling machine or large surface
(3) Measure crankshaft journals with a
grinder, make light cuts of 0.001--0.003 inch deep,
micrometer. Outside diameter of the connecting rod
removing only enough material to make block usable.
journal shall be no less than 3.122 inches. Outside
(3) Check distance from centerline of main bearing bore
diameter of main bearing journal shall be no less than
to top of block, (2, fig. 14-39). Distance shall be
3.747 inches.
14-40
