DRIVETRAIN OPERATION

TM 9-2320-280-20-1 1-18. DRIVETRAIN OPERATION The drivetrain is identical for all models covered in this manual. It converts horsepower into mechanical force to move the vehicle. Major components of the drivetrain are: ENGINE - The water-cooled 6.2 liter, V-8, Diesel engine provides up to 150 horsepower at 3600 rpm to power the vehicle. The 6.5 liter V-8 engine develops approximately 160 horsepower at 3400 rpm to power the vehicle. The engines are essentially the same on all models except those equipped with deep water fording kit installed, which adds a specially sealed dipstick, dipstick tube, and vented CDR valve. These differences do not affect engine performance. TRANSMISSION (3L80) - Adapts engine power to meet different driving conditions. The automatic transmission has three forward speeds, a reverse and a neutral. A neutral safety switch prevents the vehicle from being started with the transmission in any selector lever position except neutral. TRANSMISSION (4L80E) - Adapts engine power to meet different driving conditions. The automotic 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. 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. A complete description of these driving ranges and the recommended driving conditions during which they are used can be found in TM 9-2320-280-10. 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. 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, regardless of which wheel is slipping. This feature is called torque biasing. HALFSHAFTS - Transmits 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. 1-36