Engine Block

(9) Remove the oil pan (para 3-12) and filler

NOTE

(para 3-13), and oil pump (para 3-14).

the thrust plunger (1, fig. 3-12) and

spring (2) were removed when the gear

(10) Remove the pistons and connecting rods

cover was removed to prevent their loss

(para 3-15).

during engine overhaul.

(11) Remove the cylinder blocks (para 3-16).

(12) Remove the main bearings and crankshaft

b. Cleaning and Inspection.

(para 3-18).

(1) Clean all parts with cleaning solvent (fed.

(13) Remove the camshaft (para 3-19).

spec. P-D-680); dry thoroughly.

NOTE

(2) Inspect the camshaft of cracks, worn or

Do not remove parts from the crankcase

scored cams, worn or scored bearing surfaces, and

unless inspection indicates damage and

clogged oil passages. Replace a damaged or worn

that you must replace them.

camshaft.

(3) Inspect the plunger and spring for wear,

(14) Remove four screws (38, fig. 3-13) and lock

scoring and distortion; replace if worn or damaged.

washer (39) that secure the gear cover spacer (40) to

(4) Inspect the cam gear for cracked, chipped,

the engine block (54); remove gear cover spacer (40)

or broken gear teeth, damaged shaft bore. Replace a

and gasket (41).

damaged or worn cam gear.

(15) Remove the nuts (42) and lock washers

c. Installation.

(43) which secure cover plate (44) and gasket (45) to

(1) You will notice the cam gear has offset

the engine block; remove the cover plate and gasket.

mounting holes to insure accurate assembly. The gear

(16) Remove the straight adapter (47), pipe tee

can only be installed in the correct position for match-

(48) and pipe nipple (49) from the block.

ing the timing mark with that of the crankshaft gear.

(17) Remove the pipe plugs (50 and 51).

Secure the gear to the shaft with screw (3, fig. 3-12) and

(18) Remove the oil spray nozzles (52).

lock washer (4).

(19) Remove expansion plug (53) if damage or

(2) Install new expansion plug (37, fig. 3-13) in

leaking is evident.

engine block.

b. Cleaning and Inspection.

(3) Lubricate the camshaft journals with

(1) Remove dirt and grease deposits from the

engine oil and insert the camshaft in the block.

engine block with a putty knife. Steam-clean the block.

Remove greasy or gummy deposits with a cloth damp-

CAUTION

ened in cleaning solvent (fed. spec. P-D-680). Use

Do not insert the camshaft too far into the

compressed air when you clean the oil passages in the

block. If you bump the camshaft against

block. Remove varnish deposits with a wire brush.

the expansion plug, an oil leak could

(2) Clean all other parts with cleaning solvent;

result.

dry thoroughly.

(3) Discard and replace all gaskets.

(4) Before installing gear cover (15, fig. 3-13),

(4) Inspect the block for cracks, damaged seal-

make sure the spring (2, fig. 3-12) and plunger (1) are

ing surfaces, damaged threads, loose or damaged

in place in the end of the camshaft.

studs, or other defects. Replace the block if it is

(5) Install the main bearings and crankshaft as

cracked, or if you notice other defects which cannot be

instructed in paragraph 3-18 c.

repaired. Replace loose or damaged studs. Retap dam-

aged threads.

3-20. Engine Block

(5) Inspect the gear cover spacer for cracks,

a. Removal and Disassembly. With the engine

distortion, o r damage. Replace spacer if not

mounted on an engine overhaul stand, proceed as fol-

repairable.

lows:

(6) Inspect all remaining parts for damage;

(1) Remove oil filter from flywheel shrouding

replace any damaged parts.

(para 3-4).

c. Installation.

(2) Remove the flywheel assembly from the

(1) Install the pipe plugs (50 and 51, fig. 3-13)

engine (para 3-5).

and expansion plug (53).

(3) Remove the flywheel alternator (para 3-6).

(2) Install the oil spray nozzles (52).

(4) Remove the carburetor and manifolds

(TM 5-4320-272-12).

(3) Install the straight adapter (47), pipe tee

(48), and pipe nipple (49).

(5) Remove the air shrouding (para 3-7).

(6) Remove the governor assembly (para 3-9).

(4) Use a new gasket (45) when you install

(7) Remove the gear cover (para 3-10).

cover plate (44); secure to block with nuts (42) and

lock washers (43).

(8) Remove the iler gear and shaft (para 3-11).

3-23