measurement taken about 1/4 inch (0.625 cm) below
39, and 40) to ensure that the cylinder block oil and
the top of the cylinder. The maximum allowable
coolant passages will be properly cleaned.
cylinder wear (the difference between these two
measurements) is 0.008 inch (0.0200 cm).
(4) Replace the block if it is cracked, or if
defects cannot be repaired. Replace loose or damaged
Clean all parts in a well-ventilated area.
studs. Retap damaged threads. If a proper piston fit
Avoid inhalation of solvent fumes and
cannot be attained (para 4-9c), the cylinders are
prolonged exposure of skin to cleaning
scratched or scored, or cylinder wear exceeds 0.008
solvent. Wash exposed skin thoroughly.
inch, replace the cylinder block.
Dry cleaning solvent (Fed. Spec. P-D-680)
(5) Inspect the front end plate for cracks and
used to clean parts is potentially dangerous
distortion. Remove any burrs with a fine stone.
to personnel and property. Do not use near
(6) Inspect the oil pressure relief valve for
open flame or excessive heat. Flash point of
scoring, wear, and other damage. Inspect the spring for
solvent is 100 F. to 138 F. (38 C. to 59 C.).
cracks and misalined coils. Replace damaged oil
pressure regulator parts.
(1) Remove dirt and grease deposits and all
traces of old gasket material from flywheel housing (15,
(1) Reassembly is the reverse of removal and
fig. 4-21), valve chamber cover (7) and cylinder block
disassembly. Refer to figure 4-21.
(41), using a putty knife, gasket scraper or wire brush
(2) When installing the front end plate (19,
and dry cleaning solvent (Fed. Spec. P-D-680).
fig. 48), tighten the 3/8-inch bolts to 25 to 30 foot-
Steam-clean these pieces and boil out the block to
pounds (3.457 to 4.149 kgm) torque and tighten the
remove deposits from the coolant passages. Blow out
7/16-inch bolts to 50 to 55 foot-pounds (6.915 to 7.606
oil passages in the cylinder block and check that they
are not restricted.
(3) Install the camshaft (para 4-11c).
(2) Clean all other metal pieces with dry
(4) Install the crankshaft and main bearings
cleaning solvent (Fed. Spec. P-D-680), and allow all
pieces to dry thoroughly before reassembly.
(5) Install the pistons and connecting rods
(1) Inspect the block for cracks, damaged
(6) Install the flywheel and flywheel housing
sealing surfaces, scored or damaged bearing seats,
scored or scratched cylinder walls, damaged threads,
(7) Install the gear cover (para 4-7c).
loose or damaged studs, corrosion in the water jacket, or
(8) Install the oil pump (para 4-6c) and oil pan
(2) Check piston fit in the cylinder bores (para
(9) Install the intake and exhaust valves (para
(3) Check cylinder bore wear with an inside
(10) Install the cylinder head (para 4-3c).
micrometer. Measure the cylinder bore at 45° intervals
(11) See paragraph 3-15 for oil pressure
below the travel of the lowest piston ring where the
cylinder is not worn. Compare this measurement with a