Table 3-3. Periodic Inspection Requirements

TM 55-4920-405-13&P

Table 3-3. Periodic Inspection Requirements - Continued

Item

Period

Requirements

100 hr

Muffler

Inspect for leaks, loose mounting hardware, and defective gaskets.

Tighten loose mounting hardware.

100 hr

Valve mechanism

Inspect valve mechanism if valves are noisy or loss of engine power is

evident. Remove valve covers and adjust valve lifter clearance, if

necessary. Correct valve lifter clearance is 0.0080 inch for intake

valves, and 0.0160 inch for exhaust valves. Replace defective cover

gasket.

Remove spark plugs from engine and test cylinder compression by

turning over engine several times to stabilize compression gage read-

ing. If gage reading varies more than 10 pounds between four cylin-

ders, inspect cylinder head bolts for looseness. Tighten any loose

bolts and retest. If low compression or variation in compression per-

sists, trouble lies with cylinder head gasket, valves, or piston rings.

Spark plugs

100 hr

Inspect for loose spark plugs, poor connections, dirty or broken insula-

tors, and fouled spark `plugs. Replace damaged or worn plugs.

Clean dirty plugs and set gap to 0.0300 inch.

Magneto

100 hr

Inspect ignition magneto for loose mounting bolts and electrical connec-

tions. Correct any deficiencies noted.

Remove end cap and inspect distributor cap for cracks and corroded

terminals. Check breaker point gap. Correct gap is 0.015 inch at

full separation of points.

Starter motor

100 hr

Inspect for loose mounting bolts and electrical connections. Examine

brushes, brush holders, and springs. Inspect commutator for dirt

and scoring. Tighten loose mounting bolts and electrical connec-

tions. Replace brushes worn to one-half their original length.

100 hr

Alternator

Check alternator using procedures of paragraph 4-3.

Check for incorrect operation, loose electrical connections, and loose

100 hr

Voltage regulator

mounting hardware. Voltage regulator should allow appreciable

charge into battery after starter is used; afterwards, only a slight

charge in current should be read on AMMETER. Tighten loose mount-

ing hardware and electrical connections. Adjust or replace defective

voltage regulator.

Control panel

100 hr

Inspect control panel for loose or missing shock mounts.

Gages and meters

100 hr

Check to see that all gages indicate correctly and that glass is not

cracked or broken. Tighten loose mounting hardware and hydraulic

connections. Replace damaged or defective gage.

Check to see that all meters are tightly mounted, are operating properly,

glass is not cracked or broken, and pointers are not bent or broken.

Tighten loose mounting hardware and electrical connections. Replace

damaged or defective meter.

100 hr

Check to see that control valves operate properly, show no signs of

Control valves

packing leaks, and manual controls are tightly mounted. Tighten or

replace packing as necessary. Replace defective or damaged control

valve.

Tires

100 hr

Inspect tires for underinflation, abnormal or uneven wear, cuts, em-

bedded foreign material, and missing valve caps. Remove any

foreign matter from tires. Ensure that all tires are inflated to 60

PSI, and that all valve caps are in place.

3-10