This electronically shifted transfer case provides four mode
positions:
•Two-Wheel Drive High Range (2WD)
• Four-Wheel Drive Lock High Range (4WD LOCK)
• 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 LOCK
Four-Wheel Drive Lock High Range — This range maxi-
mizes torque to the front driveshaft, forcing the front and
rear wheels to rotate at the same speed. This range pro-
vides 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 to the front
driveshaft, forcing the 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).
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 NEU-
TRAL position without first fully engaging the park-
ing brake. The transfer case NEUTRAL position disen-
gages both the front and rear drive shafts 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.
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.
6
STARTING AND OPERATING 261
When additional traction is required, the transfer case 4WD
LOCK 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
rotating the 4WD Control Switch to the desired position.
Refer to “Shifting Procedure” in this section for specific
shifting instructions.
The 4WD LOCK and 4WD LOW positions are designed for
loose, slippery road surfaces only. Driving in the 4WD
LOCK 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 on
the lower left hand corner of the 4WD Control Switch. The
transfer case NEUTRAL position is to be used for recre-
ational towing only. Refer to “Recreational 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.
3. When the shift is complete, the indicator light for the selected position will stop flashing and remain ON.
If One Or More Of The Following Shift Conditions Are
Not Met:
1. The indicator light for the current position will remain ON.
2. The newly selected position indicator light will continue to flash.
262 STARTING AND OPERATING
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.
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
sideways 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 instrument 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.
Stationary Mode
To operate the PTO in this mode the vehicle must meet the
following conditions:
• Transmission in PARK position (vehicles equipped with
automatic transmission.)
• PTO switch has been activated.
• Parking brake applied (vehicles equipped with manual
transmission).
• Brake pedal must not be applied.
• Vehicle engine must be running.
• No vehicle, brake or clutch switch faults present.
266 STARTING AND OPERATING
•PTO must be correctly installed using the vehicle pro-
vided circuits.
The instrument cluster will display a PTO Onmessage 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 operation and return to “standard vehicle
operation” simply toggle the PTO switch to the OFF
position.
The torque converter clutch (TCC) will automatically en-
gage 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
manufacturer 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 rambodybuilder.com
Mobile Mode
To operate the PTO in this mode the vehicle must meet the
following conditions:
•Mobile mode is activated via the menu on the instru-
ment cluster display.
• (ON/OFF) switch has been activated.
• Vehicles with automatic transmission must be in PARK
or DRIVE.
6
STARTING AND OPERATING 267
6. Using the lug wrench, finish tightening the nuts using acrisscross pattern. For the proper lug nut torque speci-
fications refer to “Wheel And Tire Torque Specifica-
tions” 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.
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.
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
previously described.
9. Adjust the tire pressure when possible.
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 location. The correct direction of rotation for dual
tire installations must also be observed.
It is recommended that wheel stud nuts be kept torqued to
specifications at all times. Torque wheel stud nuts to
specifications at each lubrication interval.
7
IN CASE OF EMERGENCY 343
Wheel Nuts
All wheel nuts should be tightened occasionally to elimi-
nate 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 recom-
mended 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.
To Stow The Flat Or Spare — If Equipped
Refer to Upfitters Body Builders Guide for information on
stowing your spare tire (if equipped).
Hub Caps/Wheel Covers — If Equipped
The hub caps must be removed before raising the vehicle
off the ground.
CAUTION!
Use extreme caution when removing the front and rear
center caps. Damage can occur to the center cap and/or
the wheel if screwdriver type tools are used. A pulling
motion, not a pry off motion, is recommended to
remove the caps.
For single rear wheel (SRW) models, use the flat blade on
the end of the lug wrench to pull the hub cap off. Insert the
blade end into the pull off notch and carefully pull the hub
cap off with a back and forth motion.
On 3500 models with dual rear wheels (DRW), you must
first remove the hub caps. The jack handle driver has a
hook at one end that will fit in the pull off notch of the rear
hub caps. Position the hook and pull straight out on the
ratchet firmly. The hub cap should pop off. The wheel skins
can now be removed. For the front hub cap, use the flat
blade on the end of the lug wrench to pull the caps off. The
wheel skin can now be removed.
344 IN CASE OF EMERGENCY
WARNING!(Continued)
brake system and/or impair its performance. The
proper type of brake fluid for your vehicle is also
identified on the original factory installed hydraulic
master cylinder reservoir.
• To avoid contamination from foreign matter or mois-
ture, use only new brake fluid or fluid that has been
in a tightly closed container. Keep the master cylin-
der reservoir cap secured at all times. Brake fluid in
a open container absorbs moisture from the air
resulting in a lower boiling point. This may cause it
to boil unexpectedly during hard or prolonged brak-
ing, resulting in sudden brake failure. This could
result in a collision.
• 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.
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 lubricant should be used.
CAUTION!
Using a transmission fluid other than the manufactur-
er ’s recommended fluid may cause deterioration in
transmission shift quality and/or torque converter
shudder, and will require more frequent fluid and
filter changes. Refer to “Fluids And Lubricants” in
“Technical Specifications” for fluid specifications.
8
SERVICING AND MAINTENANCE 389
TECHNICAL SPECIFICATIONS
CONTENTS
IDENTIFICATION DATA ...................426
▫ Vehicle Identification Number .............426
BRAKE SYSTEM ....................... .426
▫ Hydraulic Brake Assist ...................427
WHEEL AND TIRE TORQUE SPECIFICATIONS . .427
▫ Torque Specifications ....................427
FUEL REQUIREMENTS ...................429
▫ 6.4L Engine .......................... .429
▫ Reformulated Gasoline ..................430
▫ Materials Added To Fuel .................430 ▫
Gasoline/Oxygenate Blends ...............431
▫ Do Not Use E-85 In Non-Flex Fuel Vehicles . . . .431
▫ CNG And LP Fuel System Modifications ......431
▫ MMT In Gasoline ...................... .432
▫ Fuel System Cautions ....................432
▫ Carbon Monoxide Warnings ...............433
FLUID CAPACITIES ..................... .434
FLUIDS AND LUBRICANTS ................435
▫ Engine ............................. .435
▫ Chassis ............................ .437
9