Section III. PRINCIPLES OF OPERATION
1-16. EQUIPMENT OPERATION.
The M992A1 requires the integrated performance of several systems to successfully complete its mission. The
electrical supply and track and suspension systems are powered by the powerpack. The auxiliary power unit provides
power to the hydraulic system.
The powerpack includes the main diesel engine and the unitized transmission and transfer assembly.
The geared transfer assembly transfers engine power to the transmission. The transmission transfers power through the left
and right final drives to the drive sprockets.
The powerpack is removed and installed as a single unit. It must be removed from the vehicle before the engine and
transmission unit can be separated.
The engine is a Detroit Diesel turbocharged eight-cylinder, V-type, two-cycle diesel.
The Allison model XTG411-4 cross-drive transmission combines transmission, steering, and braking. The driver's
compartment steering wheel is connected through linkages to hydraulic controls in the transmission. Braking is controlled
by the service brake pedal through linkages to disks in the transmission.
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