Maintenance Procedures (Cont)
Do not use paint scrapers, knives, or other metal tools on aluminum parts and
machined surfaces. Aluminum is easily gouged and machined surfaces easily
scratched by steel tools.
(6) Use reasonable care in cleaning machined surfaces with scrapers and wire brushes. Do not use
abrasive wheels or compounds on machined surfaces.
(7) Bearings. Refer to TM 9-214, Inspection, Care, and Maintenance of Antifriction Bearings. When
cleaning ball or roller bearings, place in basket and soak in dry cleaning solvent. Use paintbrush
to remove caked deposits. Never use compressed air to clean and dry caged bearings. Caged
bearings must drip and air dry. Do not spin bearings before thoroughly clean. Coat cleaned
bearings liberally with lubricating oil, then wrap in protective wrapper if not using right away.
C. Follow these general inspection instructions.
(1) Inspect hoses and lines for damage or frayed coverings. Check for breaks or worn spots caused
by kinking or contact with other parts of vehicle. Inspect fittings for damage. If fittings are
damaged, look for possible causes of damage.
(2) Inspect wiring harnesses for chafed or burned insulation. Look for causes of chafing or burns.
Inspect terminal connectors for loose connections and broken parts.
(3) Inspect all surfaces in contact with gaskets, packings, or seals for nicks, burrs, or scratches
which might damage new seals, Remove defects with crocus cloth.
(4) Inspect castings and weldments for cracks and breaks. If the following patterns appear, replace
(a) Bursts or scattered, short, sharp lines (indicates high temperature).
(b) Flakes or separate, short, wavy lines, usually in one general direction (indicates improper
(c) Grinding cracks (fine, sharp lines, tightly packed). On some surfaces, cracks may be shallow and
hard to see. Grinding cracks are usually caused by a glazed grinding wheel rubbing (instead of
cutting) and overheating the part.
(5) Inspect bearings. Clean, then lubricate bearings. Check for roughness of rotation. If rough,
replace bearing. Check for cuts, grooves, pitting, scratched, cracked or chipped races, and for
loose rollers or balls in caged bearings. If defect is found, replace bearing. Check bearing housing
or shaft for grooves, burrs, or abrasions that would indicate bearing had been turned in housing
or on shaft. If damage cannot be repaired with crocus cloth, replace defective part.
(6) Inspect bushings for scoring, burrs, roundness, sharp edges, and discoloration (overheated oil).
Replace out-of-round and overheated bushings. Remove scoring with crocus cloth, and remove
burrs and sharp edges with scraper or knife. Replace deeply scored bushings.
(7) Inspect gears for pitting, wear, and scoring.
(a) Slight scoring or minor marring of surfaces showing slight tears and scratches in direction of
sliding is not a reason to replace gears. Heavy scoring may be reason to replace gear if
equipment is not performing satisfactorily.
(b) Initial pitting, which occurs when gears are first started in service, is not serious if pitting only
reduces high spots so there is still enough contact area to carry load without hurting
(c) Destructive pitting, which follows initial pitting, may be serious because gears can be rapidly
destroyed if load carrying area of gears is severely pitted.
(d) Abrasive wear is not normally serious unless gears are gouged or have worn deep grooves.
Abrasive wear is caused by contaminated oil or grease in gear housing.
2 - 9 .
Refer to LO 9-2320-279-12 for lubricating procedures.