Section IV. ORGANIZATION OF MAINTENANCE PROCEDURES

TM9-2815-224-34&P

Engine Maintenance (Cont)

GENERAL MAINTENANCE INSTRUCTIONS (CONT).

[ 2-5.

(3) Cuts or grooves parallel to ball or roller rotation, fatigue pits (not minor machine marks or

scratches and cracks found during magnetic part icle inspection) are causes for bearing rejection.

(4) 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 inspect ion will help to show defective parts before internal inspection

of the component.

(5) 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.

(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 the load, rapid destruction may occur from continued operation.

imbedded in tooth surfaces. Particles may be metal, sand or scale, or other impurities in oil or

surrounding atmosphere.

(6) Inspect all hose surfaces for broken or frayed fabric. Check for breaks caused by sharp kinks or

contact with other parts of the truck. Inspect the fitting threads for damage. Replace any

defective part. After assembly and during initial vehicle operation period, check for leaks.

(7) Inspect all wiring harnesses for chafed or burned insulation. Inspect all terminal connectors for

loose connections and broken parts.

(8) Visually inspect all castings and weldments for cracks.

2-6. LEFT AND RIGHT SIDES OF ENGINE. The left and right sides of the engine are determined by

standing at the rear of the engine.

Section IV. ORGANIZATION OF MAINTENANCE PROCEDURES

Maintenance Procedures

2-7. ORGANIZATION OF REMOVAL, INSTALLATION, AND REPAIR PROCEDURES. Some

procedures have repair procedures combined with the removal and installation, while others have a

separate paragraph for repair of components. Components that are removed, repaired, and installed at the

same level of maintenance, DS or GS, will have the repair procedure integrated into the same primary

paragraph.

Components which are removed and installed at one level of maintenance but are repaired at a different

level of maintenance, will have the removal and installation in one primary paragraph and the repair in

another. Components which are removed and installed (but not repaired) at one level of maintenance will

be sent to the next designated level of maintenance.

2-8. ENGINE DISASSEMBLY/REASSEMBLY SEQUENCE. The procedures in this manual are

organized in accordance with the functional group codes (FGC) used in the Maintenance Allocation Chart

(MAC). However, should you have to disassemble the engine completely, table 2-1 is provided as a guide to

help you do so. The table gives the paragraphs (tasks), the technical manuals in which they are found, and

the recommended sequence in which the tasks should be performed in order to completely disassemble the

engine. Table 2-1 can also be used as a guide to reassemble an engine by following the sequence numbers

and tasks in the reverse order.

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