l Abrasive Wear. This damage is caused by the fine particles that may come from many
sources: metal detached from gear teeth or bearings, abrasives not completely removed
before assembly, sand or scale from castings, or other impurities in oil or air.
l Scoring. Slight scoring, scuffing, galling, or other surface damage is identified by tears
or scratches in the direction of sliding. It starts in areas having the highest stress and
speed. This is usually at the tip of the teeth.
l Burning. Burning is indicated by discoloration and loss of hardness due to excessive
temperature. This is caused by too much friction resulting from overload, overspeed,
lack of backlash, or faulty lubrication. if discoloring can be wiped off with clean cloth,
such discoloring usually can be traced to oilburn-trains, which are not serious.
l Roiling. This damage occurs mainly on plastic gears. Roiling is when material is pushed
out of shape without breaking off. This is caused by heavy, even loads; sliding; or
l Brinelling. This can be identified by tiny indentations or ridges on the shoulder or race
of a bearing.
6. Splines. inspect shaft splines for wear, pitting, rolling, peening, and fatigue cracks. In many
cases, the same inspection procedure will apply to gears. However, the problem, if present,
will often be much less pronounced. Have a magnetic particle inspection performed on splines,
7. Tubes and Hoses. Check all hose surfaces for broken or frayed fabric. Check for breaks
caused by sharp kinks or rubbing against other parts of the truck. Inspect air tubes for kinks.
inspect the fitting threads for damage. Replace any part found defective. Following assembly
and during initial operation, check for leaks.
8. Electrical Parts. inspect all wiring harnesses for chafed or burned insulation. Inspect all
terminal connectors for loose connections and broken parts.
9. Metal Parts. Visually inspect ail castings and weldments for cracks. Paris that carry a great
load should receive magnetic particle inspection. Critical nonferrous parts may be inspected
with fluorescent penetrant.
W A R N I N G
Drilling and grinding operations are hazardous to the eyes. Eye protection is
1. Burrs. Remove burrs from gear teeth with a fine-cut file or hand grinder. Remove burrs on
closely fitted mating surfaces by lapping the surfaces with abrasive-grade compound.
2. Exterior Parts. Chassis and exterior painted parts may be resurfaced where paint is damaged,
or where parts have been repaired, by using an abrasive disc driven by a flexible shaft. Paint
metal surfaces as required per TM-9-2320-363-10.
3. Bearings. Remove residue and oil stain from bearing races with crocus cloth.