Replacement of Helical-Coil and Threaded Inserts

thread inserts which do not fit securely in the

(1) Removal. Drill out bearing retaining

c a s t i n g or when casting threads have become

pins when used to secure bearings in castings or

galled or stripped.

retaining cages when applicable.

b. Replacement. Replace

all

unserviceable

(2) Installation.

helical-coil and screw thread inserts in the same

(a) Aline bushing, liner, or bushing-type

bearing in casting or retaining cage. Press into

manner, following instructions which accompany

figures 6-2 and 6-3. For instructional purposes

place with a suitable pressing arbor.

helical-coil inserts in the cylinder assembly will

(b) Select proper drill size for installation

of bearing retaining pins. Drill through bearing

be replaced.

and into casting or retaining cage to the proper

d e p t h so that the pin will be flush with the

bearing surface after installation. Drive retaining

pin through bearing and into casting or retaining

cage. Cut off any portion of pin that extends

above bearing.

( c ) Ream or burnish bushing liner, or

b u s h i n g - t y p e bearing to size specified in ap-

p r o p r i a t e overhaul standards table.

(d) Clean repaired parts thoroughly

before assembly or installation.

j. Oil Seals. Replace all oil seals at engine

o v e r h a u l . During field repair, replace oil seal

when thin feather edge is damaged or when seal

has become hard or brittle.

(1) Removal. Press or pry damaged oil seal

f r o m casting or adapter, being careful not to

damage bore in casting or adapter.

(2) Repair. When oil seal bore in casting or

adapter is burred or damaged to a point where

an oil-tight seal is impossible, repair or replace

casting or adapter. Remove slight nicks, burs,

1. Use a diamond-shaped punch is the insert (A) is the

and scratches from oil seal bore in casting or

serrated-teeth type to drive staked, serrated-teeth

a d a p t e r with crocus cloth dipped in dry-cleaning

section of insert from the thread in cylinder casting.

solvent or mineral spirits paint thinner.

2. Install screw thread extractor - 5120-251-1527 into

insert. Remove insert by applying constant pressure

Install new oil seal in bore

(3)

Installation.

while turning extractor (B) counterclockwise until

of casting or adapter.

insert is removed.

6-5.

R e p l a c e m e n t of Helical-Coil and

Figure 6-2. Removing helical-coil threaded

T h r e a d e d Inserts

insert from cylinder assembly using screw

a. General. Replace all helical-coil and screw

t h r e a d extractor-5120-251-1527.5