CHAPTER 1: INTRODUCTION
TM 9-2350-256-20
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COOLING SYSTEM
a.
AIR COOLING
NOTE
The following callouts are found in Figure 1-9.
Air for cooling enters the engine compartment through the grille doors. The top of the engine is shrouded and encloses
two gear-driven, axial-flow cooling fans (1) which draw the air through the cylinder fins and oil coolers and discharge the
hot air vertically from the shroud. Sheet metal baffles and deflectors direct the flow of cooling air across the cylinders.
The cooling fans (1) are attached to hubs and are mounted on shafts which are driven by the engine-driven fan drive
clutch assembly.
The fan drive shaft and gear shift are driven by a horizontal drive shaft.
The fan clutch is oil cooled. The fan clutch drive and driven disks are loaded by the centrifugal action of clutch balls and
springs housed in the clutch assembly. The balls and springs are in the driven member and apply upward force to the
clutch disks. The clutch oil enters the fan drive vertical shaft from the fan drive housing through an annular groove in the
shaft. The depth of the groove controls the amount of oil flow. The oil flows through a central hole in the shaft to a
distributor where it is dispersed to the two ball bearings and the clutch disks. The oil moves between the clutch disks by
centrifugal action and drains back through the fan drive housing into the engine oil pan. The fan clutch is designed to slip
under deep water fording conditions where the resistance of the water exceeds the friction of the clutch.
Figure 1-9. Cooling System
b.
OIL COOLING
Two engine oil coolers (2) and two transmission oil coolers (3) are mounted on the sides of the engine above the
cylinders. The cooling fans (1) draw air through the oil cooler cores to cool the oil being circulated within the coolers.
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ELECTRICAL SYSTEMS AND CIRCUITS
a.
CHARGING/STARTING SYSTEM AND VEHICLE BATTERIES
1
Engine generator. The generator is an air-cooled, 28V, dc-rated, 300-A, field-regulated unit. It is mounted on the
right side of the engine near the flywheel end, and is gear driven by the engine. An integral blower, an air intake
duct, and an outer boot and duct provide a means of cooling the generator. The electrically operated blower draws
air from the crew compartment, forces it through the generator, and exhausts it upward through an outlet near the
right camshaft gear housing.
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