TM-9-2350-261-34 Direct and General Maintenance Manual M113A2 M577A2 M1064 M1068 M1059 M901A1 Download
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TM 9-2350-261-34 THEORY OF OPERATION 0003 00 GENERAL INFORMATION: M113A2 FOV The M113A2 FOV carrier is powered by a liquid cooled 6V53, 210 horsepower diesel engine. The engine power is converted to mechanical power and transferred to the carrier tracks and other components through a transfer gearcase, transmission, differential, and final drives. The engine, transmission, and steering/braking system are driver controlled. Engine startup and shutdown are controlled by electrical signals and mechanical linkages connected to the accelerator pedal, the fuel shutoff cable, and the hand throttle cable. Steering/braking are controlled through linkages connected to the differential. ENGINE AND DRIVE TRAIN The engine converts air and diesel fuel into energy. The engine delivers this power to the transmission. A drive train transfers power from the engine to the carrier tracks. The drive train consists of the engine, transfer gearcase, transmission, differential, drive lines, final drive assemblies, and drive sprockets. COOLING SYSTEM The engine and transmission generate heat during normal operation. The cooling system transfers some of the heat to the outside to maintain a safe operating temperature. The vent fan draws air in through the radiator, circulates it around the power plant, and expels it through the exhaust grille above the vent fan. The vent fan is belt-driven from the engine crankshaft. A mixture of antifreeze and water is pumped through the cooling system to cool the engine and transmission. The engine cooling system has a capacity of 9.5 gallons (35.96 liters). The cooling system should be checked regularly. The auxiliary radiator tank, located on the transverse beam, provides space for the separation of air and liquid coolant. Stop engine if temperature goes above 200 F (93.3 C). Refer to Check/Fill Cooling System (TM 9-2350-261-10). COLD START SYSTEM The engine is equipped with a cold start system (air box heater). The air box heater heats the air entering the cylinders to assist in ignition of fuel at low ambient temperatures (below 40 F (4.4 C)). A fuel and air mixture is sprayed into the air box and a spark ignites a flame. The flame heats the engine air, which is fed directly into the cylinders to make starting easier. DIFFERENTIAL STEERING LEVERS The differential steering levers are used to steer as well as stop the carrier. Pulling on one or both of the differential steering levers applies the brakes in the differential steering unit. To turn left, gradually pull on the left steering lever. To turn right, gradually pull on the right steering lever. To slow or stop the carrier, gradually pull both steering levers. To lock the steering levers in place, push down on the brake lock buttons, located on top of the steering levers. To release the steering levers brake-lock buttons, pull back on the steering levers and the buttons will pop up. PIVOT STEER LEVERS The pivot steer levers are used to steer the carrier while in water and to turn a stopped carrier into a tight turn. To pivot steer the carrier, bring the carrier to a stop and pull on the pivot steer lever. Pulling the pivot lever applies the disc brake, which will lock up the one track and allow all of the differential power to be applied to the other back. FUEL CUTOFF CONTROL To start fuel flowing to the engine, push the fuel cutoff control all the way in. To stop fuel flow to the engine, pull the fuel cutoff control all the way out. This will shut down the engine when it is running. HAND THROTTLE CONTROL The hand throttle control is used to set the engine speed for various reasons. To set the engine speed, while pushing down the accelerator pedal, pull hand throttle control out until desired RPM is indicated by tachometer. Turn the hand throttle control clockwise to lock the control and counterclockwise to release the control. Once the hand throttle control is set, the engine will maintain the set speed without holding down the accelerator pedal. 0003 00-1 º º º º