spacing of major overhauls. The time between inspections depends upon the quality of fuel and
lubrication; frequency of cold starting; engine design features; atmospheric conditions of temperature,
dust, and humidity; and the load on the engine. Loads of less than 50 percent maximum engine output
for extended periods will increase engine maintenance.
This chapter explains the checking, lubrication, and other general maintenance of commonly
serviced parts of the locomotive. Following the pattern of chapter 1, maintenance of mechanical parts is
discussed in section I and maintenance of electrical parts in section II. Troubleshooting is discussed in
Section I. Mechanical Maintenance and Repair
Certain parts of the engine are repaired and others are replaced because they become worn. The
engine maker usually lists the expected life of each part in either miles or hours of operation.
Components subjected to continuous wear include cylinder liners, pistons and piston rings, valves, valve
springs and guides, bushings, injectors, timing gears, camshaft, rocker arms, crankshaft, parts of the
governor, and parts of the fuel, lubricating, and water pumps. A regular check should be made of the
crankshaft, the most costly part of the engine. Crankshaft distortion, caused by misalinement of the
bearings, should not exceed 2 to 3 thousandths of an inch.
Auxiliary equipment, such as the traction motor blower, belts, water pump, fuel pumps, and the
various control switches, relays, and protective devices, should be removed for cleaning, calibration,
adjustment, or replacement with completely reconditioned units during scheduled periodic inspections.
Fuel, water, and steam lines should be cleaned periodically and all valves inspected and repaired.
The following paragraphs tell the procedures used in maintaining these and other parts of the
locomotive. As usual, manufacturer's manuals and the appropriate technical manuals provide the most
complete instructions for maintenance and repairs and the instructions given here are minimal.
PISTON AND CONNECTING ROD
Following procedures given in subparagraphs a and b, remove and inspect cast aluminum pistons
and connecting rods at 75,000 miles and forged aluminum ones at 85,000 miles. Repair as