NMWR-9-2815-220 Overhaul Manual for M60 M88 Engine AVDS-1790-2CA, AVDS-1790-2DA, AVDS-1790-2DR Download
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NMWR 9-2815-220 EQUIPMENT DESCRIPTION AND DATA—Continued 0002 00 LOCATION AND DESCRIPTION OF MAJOR COMPONENTS - CONTINUED m. Cooling System. The key numbers in parentheses below refer to Figure 1 unless otherwise indicated. (1) Fans. The top of the engine is shrouded to house a rear cooling fan assembly (42) and a front cooling fan assembly (54) which draw cool air from the underside of the engine, through the cylinder fins and discharge the hot air vertically from the top shroud. The front and rear cooling fan assemblies are attached to cooling fan adapters (41) and are mounted on shafts which are driven through a fan drive clutch assembly (40). The rear fan clutch is driven by the rear fan drive shaft (36), fan drive bevel gearshaft (35), and fan driven gear-shaft (37). The front fan clutch is driven by the front fan drive shaft (34) and another fan driven gearshaft (37). (2) Fan Drive and Clutch. Figure 7 is a sectional view of the fan clutch. 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 oil flows through a central hole in the shaft to a distributor where it is dispersed to the ball bearings and to 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. (3) Engine and Transmission Oil Coolers. All transmission and engine oil cooling is accomplished by external oil coolers. The oil coolers are located on the sides of the engine above the cylinders. Air is drawn through the oil coolers by the cooling fans. A thermostatic control valve in each oil cooler controls the temperature of the oil from the cooler by permitting cold oil to bypass the coolers. This valve also permits oil to bypass the cooler in the event that the cooler becomes clogged. Models AVDS-1790-2CA and AVDS-1790-2DA are also equipped with two toggle valves, located on top of the right bank oil coolers, that permit sampling of both the engine and transmission oil. n. Crankcase Breather and Fire Extinguisher Systems. The engine crankcase breather and fire extinguisher systems are illustrated in Figure 8 in flow diagram form. (1) Crankcase Breather System. The engine crankcase breather system is completely enclosed which allows the engine to be submerged without entrance of water and permits the crankcase to be vented. The breather system is vented through the left turbosupercharger exhaust outlet into the vehicle exhaust system. (2) Fire Extinguisher System. The engine is equipped with a fire extinguisher tube located in the “V”. This tube is connected to the engine compartment fire extinguisher system. The tube has small holes drilled along the entire length to direct the carbon dioxide (CO ) fire extinguisher fluid in predetermined 2 directions around cylinders, fuel injection pump, and intercylinder components in case of fire. 0002 00-14 Change 1