STARTING AND OPERATING 273
(Continued)This electronically shifted transfer case provides four mode
positions:
• Two-Wheel Drive High Range (2WD)
• Four-Wheel Drive High Range (4WD HIGH)
• Four-Wheel Drive Low Range (4WD LOW)
• Neutral (NEUTRAL)
For additional information on the appropriate use of each
transfer case mode position, see the information below:
2WD
Rear-Wheel Drive High Range — This range is for normal
street and highway driving on dry hard surfaced roads.
4WD HIGH
Four-Wheel Drive High Range — This range provides torque
to the front driveshaft (engages four-wheel drive) which
allows front and rear wheels to spin at the same speed. This
provides additional traction for loose, slippery road surfaces
only.
4WD LOW
Four-Wheel Drive Low Range — This range provides low
speed four-wheel drive. It maximizes torque (increased torque over 4WD HIGH) to the front driveshaft; allowing
front and rear wheels to rotate at the same speed. This range
provides additional traction and maximum pulling power
for loose, slippery road surfaces only. Do not exceed 25 mph
(40 km/h) in this range.
NEUTRAL (N)
Neutral — This range disengages both the front and rear
driveshafts from the powertrain. To be used for flat towing
behind another vehicle. Refer to “Recreational Towing” in
this section for further information.
WARNING!
• You or others could be injured or killed if you leave the
vehicle unattended with the transfer case in the
NEUTRAL (N) position without first fully engaging
the parking brake. The transfer case NEUTRAL (N)
position disengages both the front and rear drive shaft
from the powertrain, and will allow the vehicle to roll,
even if the transmission is in PARK. The parking brake
should always be applied when the driver is not in the
vehicle. 5
274 STARTING AND OPERATING
This electronically shifted transfer case is designed to be
driven in the two–wheel drive position (2WD) for normal
street and highway conditions on dry hard surfaced roads).
Driving the vehicle in 2WD will have greater fuel economy
benefits as the front axle is not engaged in 2WD.
When additional traction is required, the transfer case 4WD
HIGH and 4WD LOW positions can be used to maximize
torque to the front driveshaft, forcing the front and rear
wheels to rotate at the same speed. This is accomplished by
pushing the desired position on the 4WD control switch.
Refer to “Shifting Procedure” in this section for specific
shifting instructions.
The 4WD HIGH and 4WD LOW positions are designed for
loose, slippery road surfaces only. Driving in the 4WD HIGH and 4WD LOW positions on dry hard surfaced roads may
cause increased tire wear and damage to the driveline
components.
NOTE:
The transfer case NEUTRAL button is located in the center of
the 4WD Control Switch and is pushed by using a ballpoint
pen or similar object. The transfer case NEUTRAL position is
to be used for recreational towing only. Refer to “Recre -
ational Towing” in “Starting And Operating” for further
information.
Transfer Case Position Indicator Lights
The Transfer Case Position Indicator Lights (4WD and
4LOW) are located in the instrument cluster and indicate the
current and desired transfer case selection. When you select
a different transfer case position, the indicator lights will do
the following:
If All Of The Following Shift Conditions Are Met:
1. The current position indicator light will turn OFF.
2. The selected position indicator light will flash until the
transfer case completes the shift.• The transmission may not engage PARK if the vehicle
is moving. Always bring the vehicle to a complete stop
before shifting to PARK, and verify that the transmis -
sion gear position indicator solidly indicates PARK (P)
without blinking. Ensure that the vehicle is completely
stopped, and the PARK position is properly indicated,
before exiting the vehicle. WARNING! (Continued)
STARTING AND OPERATING 281
LIMITED-SLIP DIFFERENTIAL
The limited-slip differential provides additional traction on
snow, ice, mud, sand and gravel, particularly when there is
a difference between the traction characteristics of the
surface under the right and left rear wheels. During normal
driving and cornering, the limited-slip unit performs simi -
larly to a conventional differential. On slippery surfaces,
however, the differential delivers more of the driving effort
to the rear wheel having the better traction.
The limited-slip differential is especially helpful during slip -
pery driving conditions. With both rear wheels on a slippery
surface, a slight application of the accelerator will supply
maximum traction. When starting with only one rear wheel
on an excessively slippery surface, slight momentary appli -
cation of the parking brake may be necessary to gain
maximum traction. Care should be taken to avoid sudden accelerations when
both rear wheels are on a slippery surface. This could cause
both rear wheels to spin, and allow the vehicle to slide side -
ways on the crowned surface of a road or in a turn.
POWER TAKE OFF OPERATION — IF EQUIPPED
(CHASSIS CAB ONLY)
This vehicle when equipped with PTO Prep and the AS66RC
automatic six-speed, will allow for an aftermarket upfit with
a transmission driven PTO (power take off). The customer
will have the ability to operate the PTO in either a
“stationary” or “mobile” mode. The vehicles will be factory
set to the “stationary” mode. To select “mobile” mode, you
will need to enter the commercial vehicle menu on the instru -
ment cluster screen and select mobile PTO mode. Details of
the PTO selection modes and further PTO information is
available at the Ram Truck Bodybuilders web site:
www.rambodybuilder.com .
AS66RC Six-Speed Automatic Transmission Only
The PTO drive gear (part of the AS66RC) operates at torque
converter turbine speed. The turbine speed will be less than
engine speed when the torque converter clutch is not
engaged and will be same as engine speed when the torque
converter clutch is engaged.WARNING!
On vehicles equipped with a limited-slip differential
never run the engine with one rear wheel off the ground
since the vehicle may drive through the rear wheel
remaining on the ground. You could lose control of the
vehicle. 5
282 STARTING AND OPERATING
Stationary Mode
To operate the PTO in this mode the vehicle must meet the
following conditions:
• Transmission in PARK position.
• PTO switch has been activated.
• Brake pedal must not be applied.
• Vehicle engine must be running.
• No vehicle, or brake faults present.
• PTO must be correctly installed using the vehicle provided
circuits.
The instrument cluster will display a "PTO On" message for
five seconds if the above conditions are met. Otherwise, the
instrument cluster will display a message "To Operate PTO
Shift To Park" indicating what operator action should be
taken to engage the PTO mode.
The customer has the choice to operate the PTO by utilizing
the cruise control switches or by utilizing a remote control
(provided by the PTO supplier). To operate the feature using
the cruise control switches, the customer must first activate
the PTO switch which will turn on the PTO. In order to
increase or decrease the engine idle speed, to optimize the
PTO function, the “RESUME/ACCEL” and “DECEL” cruise switches can be used respectively. To disengage PTO opera -
tion and return to “standard vehicle operation” simply
toggle the PTO switch to the OFF position.
The torque converter clutch (TCC) will automatically engage
at engine speeds above 1,200 RPM (engine speed) in PTO
stationary mode. Once engaged, the TCC will remain
applied and will not disengage until the engine speed falls
below 1,000 RPM. TCC engagement is desirable for certain
types of PTO applications (Automatic Transmission Only).
To operate the PTO via a remote switch, the customer must
make sure the above conditions are met. It is vital for proper
operation that the PTO and remote have been installed
correctly, paying special attention to ensure the vehicle
provided wiring has been connected properly. This is the
responsibility of the installer of the PTO and switches/
remote system. It is the responsibility of the PTO manufac -
turer to ensure that their electrical (switches and remote)
system is compatible with the vehicle’s electrical architecture
and software functionality.
NOTE:
Single set speed can be programmed via the PTO menu on
the instrument cluster display. Further details are available
at the Ram Truck Bodybuilders web site located at rambody -
builder.com
IN CASE OF EMERGENCY 395
5. Remove the lug nuts and pull the wheel off. Install the
spare wheel and lug nuts with the cone shaped end of the
nuts toward the wheel on single rear wheel (SRW)
models. On dual rear wheel models (DRW) the lug nuts
are a two-piece assembly with a flat face. Lightly tighten
the nuts. To avoid risk of forcing the vehicle off the jack,
do not fully tighten the nuts until the vehicle has been
lowered.
6. Using the lug wrench, finish tightening the nuts using a
crisscross pattern. For the proper lug nut torque specifica -
tions refer to “Wheel And Tire Torque Specifications” in
“Technical Specifications.” If in doubt about the correct
tightness, have them checked with a torque wrench by an
authorized dealer or at a service station. 7. Install wheel center cap (if equipped) and remove wheel
blocks. Do not install chrome or aluminum wheel center
caps on the spare wheel. This may result in cap damage.
8. Lower the jack to its fully closed position. If the jack will
not lower by turning the dial (thumbwheel) by hand, it
may be necessary to use the jack driver in order to lower
the jack. Stow the replaced tire, jack, and tools as previ -
ously described.
9. Adjust the tire pressure when possible.WARNING!
Raising the vehicle higher than necessary can make the
vehicle less stable. It could slip off the jack and hurt
someone near it. Raise the vehicle only enough to
remove the tire. WARNING!
A loose tire or jack thrown forward in a collision or hard
stop, could endanger the occupants of the vehicle.
Always stow the jack parts and the spare tire in the
places provided.
6
396 IN CASE OF EMERGENCY
Dual Rear Wheels
Slots in the wheels will assist in properly orienting the inner
and outer wheels. Align these slots when assembling the
wheels for best access to the tire valve on the inner wheel.
The tires of both dual wheels must be completely off the
ground when tightening to insure wheel centering and
maximum wheel clamping.
Dual wheel models require a special heavy-duty lug nut
tightening adapter (included with the vehicle) to correctly
tighten the lug nuts. Also, when it is necessary to remove and
install dual rear wheels, use a proper vehicle lifting device.
NOTE:
When installing a spare tire (if equipped) as part of a dual
rear wheel end combination, the tire diameter of the two
individual tires must be compared. If there is a significant
difference, the larger tire should be installed in a front loca -
tion. The correct direction of rotation for dual tire installa -
tions must also be observed
It is recommended that wheel stud nuts be kept torqued to
specifications at all times. Torque wheel stud nuts to specifi -
cations at each lubrication interval.
Refer to “Wheel And Tire Torque Specifications” in “Tech -
nical Specifications” for further information. Wheel Nuts
All wheel nuts should be tightened occasionally to eliminate
the possibility of wheel studs being sheared or the bolt holes
in the wheels becoming elongated. This is especially
important during the first few hundred miles/kilometers of
operation to allow the wheel nuts to become properly set. All
wheel nuts should first be firmly seated against the wheel.
The wheel nuts should then be tightened to recommended
torque. Tighten the wheel nuts to final torque in increments.
Progress around the bolt circle, tightening the wheel nut
opposite to the wheel nut just previously tightened until
final torque is achieved.
Refer to “Wheel And Tire Torque Specifications” in “Tech -
nical Specifications” for further information.
To Stow The Flat Or Spare — If Equipped
Refer to Upfitters Body Builder’s Guide for information on
stowing your spare tire (if equipped).
SERVICING AND MAINTENANCE 439
Automatic Transmission
Selection Of Lubricant
It is important to use the proper transmission fluid to ensure
optimum transmission performance and life. Use only the
manufacturer’s specified transmission fluid. Refer to “Fluids
And Lubricants” in “Technical Specifications”. It is
important to maintain the transmission fluid at the correct
level using the recommended fluid. No chemical flushes
should be used in any transmission; only the approved lubri -
cant should be used. Special Additives
The manufacturer strongly recommends against using any
special additives in the transmission. Automatic Transmis -
sion Fluid (ATF) is an engineered product and its perfor -
mance may be impaired by supplemental additives.
Therefore, do not add any fluid additives to the transmis -
sion. The only exception to this policy is the use of special
dyes for diagnosing fluid leaks in six-speed transmissions.
Avoid using transmission sealers as they may adversely
affect seals.• Overfilling the brake fluid reservoir can result in
spilling brake fluid on hot engine parts, causing the
brake fluid to catch fire. Brake fluid can also damage
painted and vinyl surfaces, care should be taken to
avoid its contact with these surfaces.
• Do not allow petroleum based fluid to contaminate the
brake fluid. Brake seal components could be damaged,
causing partial or complete brake failure. This could
result in a collision. WARNING! (Continued) CAUTION!
Using a transmission fluid other than the manufacturer’s
recommended fluid may cause deterioration in
transmission shift quality and/or torque converter
shudder, and (for six-speed transmissions) will require
more frequent fluid and filter changes. Refer to “Fluids
And Lubricants” in “Technical Specifications” for fluid
specifications.
7
476 TECHNICAL SPECIFICATIONS
BRAKE SYSTEM
If power assist is lost for any reason (for example, repeated
brake applications with the engine off), the brakes will still
function. However, you will experience a substantial
increase in braking effort to stop the vehicle.
If either the front or rear hydraulic system loses normal
braking capability, the remaining system will still function
with some loss of overall braking effectiveness. This will be
evident by increased pedal travel during application, greater
pedal force required to slow or stop, and activation of the
“Brake Warning Light” and the “ABS Warning Light” (if
equipped) during brake use.
The brake system power assist is provided by a hydro-boost
unit which shares fluid with the power steering system. You
may experience some clicking or hissing noises from the
hydro-boost system during hard braking conditions.
NOTE:
Under cold temperatures, pedal effort will be higher than
normal until the power steering fluid reaches operating
temperature. Hydraulic Brake Assist
The brake system power assist is provided by a hydro-boost
unit which shares fluid with the power steering system. You
may experience some clicking or hissing noises from the
hydro-boost system during hard braking conditions.
NOTE:
Under cold temperatures, pedal effort will be higher than
normal until the power steering fluid reaches operating
temperature.
WHEEL AND TIRE TORQUE SPECIFICATIONS
Proper lug nut/bolt torque is very important to ensure that
the wheel is properly mounted to the vehicle. Any time a
wheel has been removed and reinstalled on the vehicle, the
lug nuts/bolts should be torqued using a properly calibrated
torque wrench using a high quality six sided (hex) deep wall
socket.