Cuts or grooves parallel to ball or roller rotation and fatigue pits (not minor machine marks or scratches
and cracks found during magnetic particle inspection) are causes for bearing rejection.
Remove drain plugs from engine system components and inspect the sediment sticking to the plug. Grit or
fine metal particles may indicate actual or potential component failure. A few fine particles are normal. This
inspection will help to show defective parts before internal inspection of the component.
Guidelines for rejection of gears by visual inspection are not listed because of varying conditions for gear
application. The following descriptions of wear conditions may help to determine when parts are defective.
Initial pitting may occur when gears are first started in service. When pitting reduces local high spots
to allow enough contact area to carry load without further impairment, initial pitting is not serious.
Destructive pitting continues to progress after initial pitting. If there is not enough contact area
remaining to carry the load, rapid destruction may occur from continued use.
Abrasive wear is surface damage caused by fine particles carried in lubricant or particles imbedded in
tooth surfaces. Particles may be metal, sand, scale, or other impurities in oil or surrounding atmosphere.
Inspect all hose surfaces for broken or frayed fabric. Check for breaks caused by sharp kinks or contact
with other parts of vehicle. Inspect the fitting threads for damage. Replace any defective part. After assembly and
during initial vehicle operation, check for leaks.
Inspect all wiring for chafed or burned insulation. Inspect all terminal connectors for loose connections
and broken parts.
Visually inspect all castings and weldments for cracks.
Clean all parts before inspection. Check for defects such as physical distortion, wear, cracks, and pitting.
e. Cleaning Procedures.
Drycleaning solvent P-D-680 is toxic and flammable. Wear protective goggles and gloves and use
only in a well ventilated area. Avoid contact with skin, eyes and clothing and dont breathe vapor.
Do not use near open flame or excessive heat. The flash point is 100°F to 140°F (38°-60°C). If you
become dizzy while using cleaning solvent, get fresh air immediately and get medical aid. If contact
with eyes is made, wash your eyes with water and get medical aid immediately.
Compressed air used for cleaning and drying purposes must be reduced to 30 psi (207 kPa) and used
only with adequate chip guarding and personal protection equipment.
Do not use wire brushes, abrasive wheels, or compounds to clean parts, unless specifically approved in the
detailed instructions. Dimensional characteristics of machined surfaces can be altered and may weaken a highly
Soak parts in drycleaning solvent P-D-680 (item 54, appendix E) and wash away deposits by sloshing or
spraying. When necessary, brush with a soft bristle brush (item 5, appendix E) moistened in drycleaning solvent. Use a
jet of compressed air to dry parts, except bearings, after cleaning. Bearings must drip and air dry.