POWER TRAIN (Cont)

TM 9-2320-364-34-1

1-10. POWER TRAIN (CONT).

Do not allow a truck to coast in neutral. Engine braking is nullified and the transmission will not receive

adequate lubrication.

(b) Select the Neutral (N) pad when checking truck accessories and for extended periods of engine idle

operation. The push button range selector will automatically select neutral when the master switch is turned on.

Touch the reverse (R) pad on the selector. The light under the Reverse (R) pad will light and the reverse warning

signal on rear of truck will be activated.

(d) When the ECU detects a serious problem in the system, a beeper tone is produced for 10 seconds and

a "DO NOT SHIFT" light is activated to warn the driver that the transmission is held-in-gear. Selecting another pad

will have no affect or change, nor will a tone sound be produced.

(3) All lubricating and clutch-applied oil is provided by an engine-driven pump (in the transmission). Because

of the pump location ahead of the transmission gearing and clutches, the engine cannot be started by pushing or

towing the truck. Therefore, anytime that the truck must be towed, or pushed, the drive-line must be disconnected.

c. Transfer Case. The truck transfer case has two speeds and a 30/70 differential. The transfer case 30/70

differential provides full time, all wheel drive and proportions approximately 30 percent of the torque to the front

tandem and 70 percent of the torque to the rear tridem. The differential has a driver-controlled air actuated lock-up

mechanism which consists of a sliding lockout collar that locks the differential housing to the output shaft. This

differential lock-up provides increased mobility in adverse operating conditions.

d. Suspension. The front tandem suspension is a walking beam suspension with a special low-friction spring.

The third axle suspension is an air ride suspension. The rear tandem suspension is a specially designed low-friction

spring.

(1) The suspension system design maintains tire/ground contact under adverse terrain profiles and conditions.

The design equalizes loads between axles and provides the necessary roll stability to operate on a 30 percent side slope.

The truck uses 16.00R20 tires of a tubeless radial design.

(2) The truck uses three steering axles. The front tandem axle wheels and the last axle wheels steer. Power

steering controls the steering gear at each steering axle. The power steering pump is direct driven at the engine. The

cab steering wheel provides directional input to the first and second axle steering gears. A control link from the first

axle master steering gear provides a mechanical link to the second axle slave steering gear. The second axle slave gear

provides directional control from a rotary output shaft to the steering gear on the fifth axle. The steering gears are

sized to turn the wheels when the truck is fully loaded.

Axles. The truck uses a three drive/steer hub reduction axle and two hub reduction axle design.

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