GENERAL MAINTENANCE INSTRUCTIONS -- CONTINUED
INSPECTION -- CONTINUED
Bushings, Liners, and Bushing--type Bearings
Check all bushings, liners, and bushing--type bearings for secure fit in their respective casting or mating part, and
for evidence of heating, which may be indicated by discoloration of bushing or bearing surface.
Inspect for wear, burrs, nicks, or out--of--round condition.
Check for dirt in lubrication holes or grooves. Holes and grooves must be clean and free from damage to ensure
Inspect thrust faces of bushing--type bearings for wear and by temporarily assembling mating parts and checking
end play with a feeler gage inserted between the thrust faces.
Check for conformance to the applicable repair standards.
Generally, metal--encased oil seals are mandatory replacement parts and must be replaced during repair.
Helical--Coil and Screw Thread Inserts
Description To permit higher stresses on studs and bolts which are set in aluminum castings, it is common prac-
tice to install inserts of a stronger metal into which the studs or bolts are threaded. Helical--coil and screw thread
inserts are designated to perform this function. The inserts are spiral steel coils having a right hand thread--shaped
form on the inside and on the outside diameter of the coils. A bar or tang at the bottom end of the coil, which is
engaged by an inserting tool, is used for threading the insert into the casting. Some inserts have a serrated tooth
section at the top end of the coil to stake them in place in the castings. Other inserts have turns at the center of
the coil in the form of a hexagon. This provides a locking effect when the stud or bolt is threaded into the insert.
Inspection Inspect all screw thread inserts for a secure fit in the casting and for galled or stripped threads.
Straighten parts as necessary and check for broken welds, loose rivets or weld nuts. If parts are cracked or torn,
they must be repaired or replaced. Check shroud seals for hardness, tears, or other damage. Mark damaged
seals for replacement if the part is otherwise serviceable.