Castings

and

Bushing-type

Bushings,

Liners,

c. C a s t i n g s .

Bearings.

(1) Inspect all ferrous (cast iron, steel, etc.)

(1) Check all bushings, liners, and bushing-

castings for cracks with magnetic-particle in-

spection e q u i p m e n t . I n s p e c t a l l n o n f e r r o u s

type bearings for secure fit in their respective

for cracks using

casting

mating

part,

and

for

evidence

castings)

(aluminum

inspection

flourescent-penetrant

equipment.

heating, which may be indicated by discoloration

of bushing or bearing surface.

Suspected cracks in the nonferrous casting can

also be inspected with a spot check dye penetrate

(2) Inspect for wear, burs, nicks or out-of-

round condition.

or a magnifying glass (five power magnification

minimum)

and

strong

light

dye

check

(3) Check for dirt in lubrication holes or

grooves. Holes and grooves must be clean and

method. Check particularly the areas adjacent to

free from damage to insure proper lubrication.

studs,

pipe

plugs,

threaded

inserts

and

(4) Inspect thrust faces of bushing-type

sharp

corners

and

fillets.

bearings for wear and by temporarily assembling

(2) Inspect machined surfaces of castings

mating parts and checking end play with a feeler

for nicks, burs, or raised metal. Mark damaged

gage inserted between the thrust faces.

areas

for

repair.

(5) Check for conformance to the applicable

(3) Check all mating flanges and

mounting

overhaul standards.

pads with a straight edge or surface

plate for

i. Oil Seals. All oil seals must be replaced at

warpage. Inspect mating flanges and

mounting

engine overhaul. Generally, metal encased oil

pads for discoloration which may

indicate

seals are long-life parts and do not have to be

persistent oil leakage.

replaced

during

field

repair

inspection

in-

(4) Inspect all tapped openings for stripped

dicates seals are in good condition.

damaged threads.

(1) Inspect for damage to the thin feather

(5) Check all castings for conformance to

the applicable repair and rebuild standards.

edge of oil seal which contacts rotating part.

d. Ball and Needle Bearings. Refer to TM 9-

(2) Inspect sealing feather edge for softness

214 for inspection of anti friction bearings.

and

pliability.

Check all bearings for conformance to the ap-

(3) Replace damaged or

questionable

seals

plicable overhaul standards.

during field engine repair.

e. Studs. Inspect all studs for damaged or

j. Helical-coil and Screw Thread Inserts.

(1) D e s c r i p t i o n . T o p e r m i t h i g h e r s t r e s s e s

stripped threads, bent or loose condition, or for

any signs of stretching.

on studs and bolts which are set in aluminum

Inspect dowel pins for

f. Dowel Pins.

castings, it is common practice to install insets of

looseness or damage. Mark loose pins for repair.

a stronger metal into which the studs or bolts are

g. G e a r s a n d S h a f t s .

threaded. Helical-coil and screw thread inserts

Note. There are no established wear limits for

are designed to perform this function. The in-

gear teeth and splines. Good judgment is

serts are spiral steel coils having a right hand

required to determine need for replacement.

thread-shaped form on the inside and on the

outside of the coils. A bar or tang at the bottom

(1) Inspect all gears and shafts for cracks

using magnaflux equipment. When magnaflux

end of the coil, which is engaged by an inserting

equipment is not available, use a magnifying

tool, is used for threading the insert into the

glass (five power magnification minimum) and a

casting.

Some

inserts

have

serrated

tooth

strong light.

s e c t i o n at the top end of the coil to stake them in

place in the castings. Other inserts have turns at

(2) Inspect all gear teeth and splines for

wear, sharp fins, burs, and galled or pitted

the center of the coil in the form of a hexagon.

surfaces.

This provides a locking effect when the stud or

bolt is threaded into the insert.

(3) Inspect shaft and gear hub splines for

damage, wear, and for fit with splines on mating

(2) Inspection. Inspect all helical-coil

and

screw thread inserts for secure fit in the casting

parts. Mating splines

must

match

without

binding or looseness.

and for galled or stripped threads.

Straighten

parts

Painted

Parts.

(4) Check all gears and shafts for con-

formance to the applicable overhaul standards.

6-4