transmission RAM CHASSIS CAB 2019 Workshop Manual

STARTING AND OPERATING 271
To exit ERS mode, simply push and hold the GEAR+ switch
until the gear limit display disappears from the instrument
cluster.
When to Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting occurs,
push the TOW/HAUL switch to activate TOW/HAUL
mode. This will improve performance and reduce the poten -
tial for transmission overheating or failure due to excessive
shifting. TOW/HAUL Switch
The “TOW/HAUL Indicator Light” will illuminate in the
instrument cluster to indicate that TOW/HAUL mode has
been activated. Pushing the switch a second time restores
normal operation. Normal operation is always the default at
engine start-up. If TOW/HAUL mode is desired, the switch
must be pushed each time the engine is started.WARNING!
Do not downshift for additional engine braking on a
slippery surface. The drive wheels could lose their grip
and the vehicle could skid, causing a collision or
personal injury.
5

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)

276 STARTING AND OPERATING
Shifting Procedure
NOTE:
• If any of the requirements to select a new transfer case
position have not been met, the transfer case will not shift.
The position indicator light for the previous position will
remain ON and the newly selected position indicator light
will continue to flash until all the requirements for the
selected position have been met.
• If all the requirements to select a new transfer case position
have been met, the current position indicator light will
turn OFF, the selected position indicator light will flash
until the transfer case completes the shift. When the shift is
complete, the position indicator light for the selected posi -
tion will stop flashing and remain ON.
2WD To 4WD HIGH
Push the desired position on the 4WD control switch to shift
the transfercase. Shifts between 2WD and 4WD HIGH can be
done with the vehicle stopped or in motion. With the vehicle
in motion, the transfer case will engage/disengage faster if
you momentarily release the accelerator pedal after turning
the control switch. If the vehicle is stopped, the ignition
switch must be in the ON position with the engine either
running or off. This shift cannot be completed if the ignition
switch is in the ACC position. NOTE:
The four-wheel drive system will not allow shifts between
2WD/4WD HIGH if the front and/or rear wheels are spin -
ning (no traction). In this situation, the selected position indi -
cator light will flash and the original position indicator light
will remain ON. At this time, reduce speed and stop spin -
ning the wheels to complete the shift.
2WD Or 4WD HIGH To 4WD LOW
NOTE:
When shifting into or out of 4WD LOW some gear noise may
be heard. This noise is normal and is not detrimental to the
vehicle or occupants.
Shifting can be performed with the vehicle rolling 2 to 3 mph
(3 to 5 km/h) or completely stopped. You can use either of
the following procedures:
Preferred Procedure
1. With the engine running, slow the vehicle to 2 to 3 mph (3
to 5 km/h).
2. Shift the transmission into NEUTRAL.
3. While still rolling, push the desired position on the
transfer case control switch.

STARTING AND OPERATING 277
4. After the desired position indicator light is ON (not
flashing), shift the transmission back into gear.
Alternate Procedure
1. Bring the vehicle to a complete stop.
2. With the ignition switch in the ON position and the
engine running, shift the transmission into NEUTRAL.
3. Push the desired position on the transfer case control
switch.
4. After the desired position indicator light is ON (not
flashing), shift the transmission back into gear.
NOTE:
• If Steps 1 or 2 of either the Preferred or Alternate Proce -
dure are not satisfied prior to attempting the shift, then the
desired position indicator light will flash continuously
while the original position indicator light is ON, until all
requirements have been met.
• The ignition switch must be in the ON position for a shift
to take place and for the position indicator lights to be
operable. If the ignition switch is not in the ON position,
the shift will not take place and no position indicator lights
will be on or flashing. Manually Shifted Transfer Case — If Equipped
The transfer case provides four mode positions:
• Two-Wheel Drive High Range (2H)
• Four-Wheel Drive Lock High Range (4H)
• Neutral (N)
• Four-Wheel Drive Low Range (4L)
For additional information on the appropriate use of each
transfer case mode position, see the information below:
2H
Two-Wheel Drive High Range — This range is for normal
street and highway driving on dry, hard surfaced roads.
4H
Four-Wheel Drive Lock High Range — This range locks the
front and rear driveshafts together forcing the front and rear
wheels to rotate at the same speed. Additional traction for
loose, slippery road surfaces only. 5

STARTING AND OPERATING 279
Because four-wheel drive provides improved traction, there
is a tendency to exceed safe turning and stopping speeds. Do
not go faster than road conditions permit.
NOTE:
Delayed shifts out of four-wheel drive may be experienced
due to uneven tire wear, low or uneven tire pressures, exces -
sive vehicle loading, or cold temperatures.
Two-Wheel Drive High Range (2H)
Rear-Wheel Drive High Range — This range is for normal
street and highway driving on dry hard surfaced roads. Four-Wheel Drive High Range (4H)
Four-Wheel Drive High Range — This range locks the front
and rear driveshafts together forcing the front and rear
wheels to rotate at the same speed. Additional traction for
loose, slippery road surfaces only.
Neutral (N)
Neutral — This range disengages the front and rear drivesh -
afts from the powertrain. To be used for flat towing behind
another vehicle. Refer to “Recreational Towing” in “Starting
And Operating” for further information.
Four-Wheel Drive Low Range (4L)
Four-Wheel Drive Low Range — This range locks the front
and rear driveshafts together forcing the front and rear
wheels to rotate at the same speed. Additional traction and
maximum pulling power for loose, slippery road surfaces
only. Do not exceed 25 mph (40 km/h).WARNING!
You or others could be injured or killed if you leave the
vehicle unattended with the transfer case in the
NEUTRAL position without first fully engaging the
parking brake. The transfer case NEUTRAL position
disengages 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.
CAUTION!
Do not use 4L (Low) range when operating the vehicle on
dry pavement. Driveline hardware damage can result. 5

280 STARTING AND OPERATING
Shifting Procedure — Manually Shifted Transfer Case
2H To 4H
Shifting between 2H and 4H can be made with the vehicle
stopped or in motion. If the vehicle is in motion, shifts can be
made up to 55 mph (88 km/h). With the vehicle in motion,
the transfer case will engage/disengage faster if you
momentarily release the accelerator pedal after completing
the shift. Apply a constant force when shifting the transfer
case lever.
2H Or 4H To 4L
NOTE:
When shifting into or out of 4L some gear noise may be
heard. This noise is normal and is not detrimental to the
vehicle or occupants.
With the vehicle rolling at 2 to 3 mph (3 to 5 km/h), shift the
transmission into NEUTRAL. While the vehicle is coasting at
2 to 3 mph (3 to 5 km/h), shift the transfer case lever firmly
to the desired position. Do not pause in transfer case
NEUTRAL. NOTE:
• Pausing in transfer case NEUTRAL in vehicles equipped
with an automatic transmission may require shutting the
engine OFF to avoid gear clash while completing the shift.
If difficulty occurs, shift the transmission into NEUTRAL,
hold your foot on the brake, and turn the engine OFF.
Complete the range shift to the desired mode.
• Shifting into or out of 4L is possible with the vehicle
completely stopped, however difficulty may occur due to
the mating clutch teeth not being properly aligned. Several
attempts may be required for clutch teeth alignment and
shift completion to occur. The preferred method is with the
vehicle rolling 2 to 3 mph (3 to 5 km/h). Avoid attempting
to engage or disengage 4L with the vehicle moving faster
than 2 to 3 mph (3 to 5 km/h).
• Do not attempt to shift into or out of 4L while the transmis -
sion is in gear.
Transfer Case Position Indicator Light
The “Transfer Case Position Indicator Light” in the instru -
ment cluster is used to alert the driver that the front axle is
fully engaged and all four wheels are driving.

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

STARTING AND OPERATING 283
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 instrument
cluster display.
• (ON/OFF) switch has been activated.
• Transmission must be in PARK or DRIVE.
• Parking brake must not be applied.
• Brake pedal must not be applied.
• No vehicle or brake faults present.
• Vehicle engine must be running.
• PTO must be correctly installed using the vehicle provided
circuits.
The customer may choose to use the PTO while the vehicle is
moving. To do so, the PTO function must be activated prior
to taking the vehicle out of PARK. This is accomplished by
activating the upfitter-provided PTO on/off switch. At this
point, the customer may place the vehicle in a forward or
reverse gear and have PTO operation once the vehicle begins
to move. To disengage PTO operation and return to “stan -
dard vehicle operation” simply toggle the on/off switch to
the OFF position. NOTE:
For application specific information with respect to PTO and
pump requirements and additional vehicle information
(wiring schematics, preset idle values, engine speed limits,
and vehicle hardware and software requirements) please
refer to the Body Builders Guide by accessing rambody -
builder.com and choosing the appropriate links.
POWER STEERING
Hydraulic Power Steering
The standard power steering system will give you good
vehicle response and increased ease of maneuverability in
tight spaces. The system will provide mechanical steering
capability if power assist is lost.
If for some reason the power assist is interrupted, it will still
be possible to steer your vehicle. Under these conditions, you
will observe a substantial increase in steering effort, espe -
cially at very low vehicle speeds and during parking maneu -
vers. 5