REPAIR - TM-9-2815-204-350215

(3) R e p l a c e crankshaft when journals are

(6) Inspect crankshaft gear key (M, fig. 351)

grooved,

burned,

deeply

nicked,

for nicks and snug fit in keyway. Nicks

scratched, galled, scuffed, or if crank-

in key may be removed with a fine oil

s h a f t is discolored from overheating.

stone. A loose key must be replaced.

Repair minor imperfections in journals

(7) I n s p e c t

crankpin plug (MM-3) (early

by polishing with crocus cloth dipped

i n dry-cleaning s o l v e n t o r m i n e r a l

models)

for bent condition or cracks

spirits paint thinner.

around

bolt hole. Replace bent or

cracked

plugs.

(4) R e p l a c e a c r a c k e d c r a n k s h a f t o r a

167. REPAIR

c r a n k s h a f t showing evidence of wear

due to bent or twisted connecting rods.

a . Regrinding. C r a n k s h a f t s having out-of-

round bearing journals or when either connect-

b . Crankshaft Bushing-type Pilot Bearing

i n g rods or main bearing journals are worn

Replacement (fig. 337).

b e y o n d limits specified in repair and rebuild

(1) Remove damaged or worn bushing-type

s t a n d a r d s (par. 292), regrind crankshaft to a

limit of 0.010 or 0.020-inch undersize. Under-

pilot bearing (MM-6, fig. 322) (par. 67)

s i z e bearing s e t s are available for rebuild.

following step A for figure 94.

The crankshaft must be held to limits established

in repair and rebuild standards and to the

(2) Install new bushing-type pilot bearing

following instructions.

( M M - 6 , fig. 322) (par. 67). Refer to

figure 95.

(1) S u r f a c e roughness on crankpins and

j o u r n a l s must not exceed 20 micro

168. ASSEMBLY

inches.

(2) C r a n k s h a f t must be inspected by the

Refer to figures 334 and 335 and reverse the

electro magnaflux method for fractures

sequence of instructions to assembly the crank-

and surface cracks after finishing.

shaft.

Section IV. REBUILD OF CAMSHAFT ASSEMBLY AND THRUST PLATE

169. DISASSEMBLY

170. CLEANING AND INSPECTION

The only component part removed from the

a . Cleaning. Refer to paragraph 152 for

camshaft assembly is the camshaft gear Wood-

general cleaning procedures.

ruff key (fig. 338). The tachometer drive sleeve

--. I n s p e c t i o n .

is a press fit in the end of the camshaft and

is not removed unless it is damaged.

(1) Camshaft. Inspect camshaft (AM, fig.

FIGURE 338. CAMSHAFT ASSEMBLY AS REMOVED FROM ENGINE.

208