M978 Tanker Maintenance Procedures Instructions (Cont)
22-2. GENERAL MAINTENANCE INSTRUCTIONS (CONT).
d. Follow these inspection instructions when working on the tanker and tanker components:
Inspect all surfaces in contact with gaskets, coupling gaskets, packings, or seals for nicks, burrs,
scratches or other damage, which might damage the new seal upon reassembly. If any defect is
found, remove before assembly.
Defects which may cause bearing binding or misalinement are cause for rejection.
Nicks or gouges outside race load area are not cause for rejection.
Inspect bearings for rusted or pitted bearings, races, or separators. Inspect bearings and races for
abrasion and serious discoloration.
Cuts or grooves parallel to bearing or roller rotation and fatigue pits are causes for bearing
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 determine when
parts are defective.
(a) Initial pitting may occur when gears are first started in service. When pitting reduces local high
spots so there is still enough contact area to carry load without further impairment, initial
pitting is not serious.
(b) Destructive pitting continues to progress after initial pitting. If there is not enough contact area
remaining to carry load, rapid destruction may occur from continued operation.
(c) Abrasive wear is surface damage caused by fine particles carried in lubricant or particles
embedded in tooth surfaces. Particles can be metal, sand, or scale in the oil.
(5) Inspect all hose surfaces for damaged or deteriorated material. Check for breaks caused by sharp
kinks or contact with other parts of vehicle. Inspect fitting threads for damage. Replace
defective parts. After assembly and during initial vehicle operation period, check for leaks.
(6) Inspect wiring harnesses for chafed or burned insulation. Inspect all terminal connectors for
loose connections and broken parts.
(7) Visually inspect all castings and weldments for cracks.