GENERAL MAINTENANCE INSTRUCTIONS -- CONTINUED
GENERAL REPAIR -- CONTINUED
Studs -- Continued
Replacement Repair minor thread damage in tapped holes with a used tap.
When threads are stripped or damaged, or when stud is removed from an aluminum casting for loose fit, always
replace stud with next larger oversize, or in cases of complete thread pullout, drill out threaded holes, tap hole for
thread insert, install insert and standard stud for repair. Markings and color code indicates whether stud is stan-
dard or oversize. Check marking and color as shown in illustration to be sure replacement is the proper size.
When the threads on each end of the stud are a different
size, the coarse thread end must enter the aluminum
Studs available for replacement, as shown in illustration, are marked on the coarse thread end of stud.
Apply a small amount of lubricant (item 12, WP 0100 00) to threads before installing stud.
Drive stud into tapped hole slowly to prevent heating. Drive stud to setting height given in appropriate table in
Chapters 6 and 7.
When tapped holes in castings cannot be fitted with oversize studs, the holes in the castings can be fitted with
screw thread inserts (WP 0012 00) and studs of the original size can then be installed.
Replace loose dowel pins. If original dowel pin was only slightly loose, install new pin using sealing compound
(item 2, WP 0100 00). In cases where the dowel pin hole is grossly out--of--round, it will be necessary to drill the
hole oversize, fashion a bushing, and install a new dowel pin in the bushing.
Retouch or paint parts as necessary to produce an acceptable part. Retouch or re--paint parts in their original color
in accordance with procedures contained in TM 43--0139.
Gears and Shafts
Replace all cracked gears and shafts, and shafts that are bent or twisted.
Replace all gears and shafts which do not conform to tolerances specified in the repair standards tables.