Master light switch
Cab dome light switch
Directional signal lever
Oil temperature warning switch
Inter-axle differential lockout
Trailer brake lever
Water temperature warning light
Dry road switch
Windshield washer control
Engine oil pressure gauge
Windshield wiper switch
Headlight dimmer switch
Left turn directional lamp
Fuel level gauge
Brake treadle valve
High beam indicator
Water temperature gauge
Main transmission shift lever
Right turn directional lamp
Cab heater switch
Transmission shift button
Air pressure gauge
Transfer case control lever
Park abort control
Front axle control lever
Engine throttle control
Low air pressure indicator
Reservoir drain valve
Hazard warning switch light
Windshield wiper hand lever
Tractor protection valve
Hazard warning switch
Figure 6-1. Carrier instruments and controls.
(3) Place the lever in the RELEASE position. The
or slippery conditions. When front axle drive is used, the
carrier brake system is now ready for normal operation.
operator should also consider engaging the interaxle
differential lockout, as well as the SLIPPERY ROAD
d. Towing Another Vehicle. To tow, another vehicle,
b. Engaging Front Axle Drive. To engage the
proceed as follows:
front axle drive, proceed as follows:
(1) Connect both the EMERGENCY and SERVICE
(1) Stop the vehicle completely.
BRAKE systems at the rear of the truck crane to the
(2) Shift the transfer case into the LOW position.
vehicle to be towed.
(3) Shift the front axle control lever (41, fig. 6-1)
into the IN position.
EMERGENCY position and run the engine until the
(4) Shift the main transmission lever to the desired
carrier air pressure is at least 50 psi. It is recommended
starting position and bring the carrier up to operating
that the towed vehicle not be moved until it reaches
speed in the usual manner.
normal system pressure. When the low air pressure flag
c. Disengaging Front Axle Drive. Disengage
rises, place the lever in the RELEASE position.
front axle drive as follows:
(3) Depress valve (15, fig. 6-1). The towed vehicle
(1) Stop the carrier.
brakes will now operate when the carrier air brakes
(2) Shift the transfer case into the HIGH range.
operate, and the carrier can be driven normally. The
(3) Shift the front axle control lever to the OUT
trailer brake lever (33, fig. 6-1) is used to apply the
brakes on the towed vehicle only. Be careful to avoid too
(4) Bring the carrier up to speed, using the main
much speed on grades and use more caution than usual
transmission shift lever.
when towing another vehicle.
6-9. Front Axle Drive
a. General. The use of the driving front axle
should be restricted to off highway or very rough
Section IV. OPERATION UNDER USUAL CONDITIONS
specific operations for which the equipment is designed.
a. The instructions in this section are published
a. Preparation for Starting.
for the information and guidance of personnel
responsible for operation of the Model M320T truck
b. The operator must be thoroughly familiar with
(2) Lubricate the carrier as specified in (LO 5-3810-
the use of the controls of Model M320T truck crane
carrier. This section gives instructions on starting and
stopping the carrier, operation of the carrier, and on
coordinating the basic motions required to perform the