TM-9-2320-387-10 HMMWV Operator Manual Download
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1-15. DRIVETRAIN OPERATION The drivetrain converts horsepower into mechanical force to move the vehicle. Major components of the drivetrain are: TRANSMISSION – Adapts engine power to meet different driving conditions. The automatic transmission has four forward speeds, a reverse, a neutral and a park. A neutral safety switch prevents the vehicle from being started with the transmission in any selector lever position except park and neutral. A ENGINE – The 6.5 liter V-8 turbocharged engine develops approximately 190 horsepower at 3,400 rpm. Engines equipped for deep water fording have a specially-sealed dipstick, dipstick tube, and vented CDR valve. B TRANSFER CASE – Directs engine-to-transmission power to front and rear differentials simultaneously. This condition means the vehicle is always in four-wheel drive. The transfer case allows for selection of three drive ranges and a neutral position. (See table 1-7). C PROPELLER SHAFTS – Link transfer case to differentials. Universal joints, located at either end of the front and rear propeller shafts, permit inline driving power between the transfer case and differentials even though they are mounted at different angles. D F E G DIFFERENTIALS – Transmit driving power, via halfshafts and geared hubs, to left and right wheels. The differential ensures power is applied to the wheel having traction. This feature is called torque biasing. HALFSHAFTS – Transmit power from differentials to geared hubs. GEARED HUBS – Serve as the front wheel steering spindle and act as the final drive components to front and rear wheels. TM 9-2320-387-10 1-14 Change 1 ~ A B C D E F G D E F