wheel Ram 3500 Chassis Cab 2018 Workshop Manual

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).
This transfer case is intended to be driven in the 2H
position for normal street and highway conditions such as
dry, hard surfaced roads.
When additional traction is required, the 4H and 4L
positions can be used to lock the front and rear driveshafts
together and force the front and rear wheels to rotate at the
same speed. This is accomplished by simply moving the
gear selector to the desired positions once the appropriate
speed and gear requirements are met, refer to “Shifting
Procedure – Manually Shifted Transfer Case” in this section
for further information.
The 4H and 4L positions are intended for loose, slippery
road surfaces only. Driving in the 4H and 4L positions on
dry, hard surfaced roads may cause increased tire wear and
damage to the driveline components.
The “Transfer Case Position Indicator Light” in the instru-
ment cluster will alert the driver that the vehicle is infour-wheel drive and that the front and rear driveshafts are
locked together. This light will illuminate when the transfer
case is shifted into either the 4H or 4L position. There is no
light for the 2H or NEUTRAL positions on some models.
When operating your vehicle in 4L, the engine speed is
approximately three times that of the 2H or 4H positions at
a given road speed. Take care not to overspeed the engine
and do not exceed 25 mph (40 km/h).
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference will adversely affect shifting and can cause
damage to the drivetrain.
NOTE:
Do not attempt to make a shift while only the front
or rear wheels are spinning, as this can cause damage to
driveline components.
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, excessive vehicle loading, or cold temperatures.
256 STARTING AND OPERATING

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.
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
driveshafts 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).
CAUTION!
Do not use 4L (Low) range when operating the vehicle
on dry pavement. Driveline hardware damage can
result.
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STARTING AND OPERATING 257

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 com-
pleting 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 align-
ment 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
transmission 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.
258 STARTING AND OPERATING

Electronically Shifted Transfer Case (Four-Position
Switch) — If Equipped
The electronic shift transfer case is operated by the 4WD
Control Switch (Transfer Case Switch), which is located on
the instrument panel.
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
Four-Position/Part Time Transfer Case
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STARTING AND OPERATING 259

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.
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.
260 STARTING AND OPERATING

If One Or More Of The Following Shift Conditions Are
Not Met:
1. The indicator light for the current position will remainON.
2. The newly selected position indicator light will continue to flash.
3. The transfer case will notshift.
NOTE: Before retrying a selection, make certain that all
the necessary requirements for selecting a new transfer
case position have been met. To retry the selection, turn the
control switch back to the current position, wait five
seconds, and retry selection. To find the shift requirements,
refer to the Shifting Procedure for your transfer case,
located in this section.
The “SVC 4WD Warning Light” monitors the electronic
shift four-wheel drive system. If this light remains on after
engine start up or illuminates during driving, it means that
the four-wheel drive system is not functioning properly
and that service is required.WARNING!
Always engage the parking brake when powering
down the vehicle if the “SVC 4WD Warning Light” is
illuminated. Not engaging the parking brake may
allow the vehicle to roll, which may cause personal
injury.
NOTE: Do not attempt to make a shift while only the front
or rear wheels are spinning, as this can cause damage to
driveline components.
When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD or
4WD LOCK positions at a given road speed. Take care not
to overspeed the engine and do not exceed 25 mph
(40 km/h).
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference in tire size can cause damage to the
drivetrain.
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.
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STARTING AND OPERATING 261

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 posi-
tion will remain ON and the newly selected position
indicator light will continue to flash until all the require-
ments for the selected position have been met. To retry a
shift: return the control switch back to the original
position, make certain all shift requirements have been
met, wait five seconds and try the shift again.
• 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 position will stop flashing and remain
ON. 2WD To 4WD LOCK
Rotate the 4WD control switch to the desired position.
Shifts between 2WD and 4WD LOCK can be done with the
vehicle stopped or in motion. With the vehicle in motion,
the transfer case will engage/disengage faster if you mo-
mentarily 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 LOCK if the front and/or rear wheels
are spinning (no traction). In this situation, the selected
position indicator light will flash and the original position
indicator light will remain ON. At this time, reduce speed
and stop spinning the wheels to complete the shift.
2WD Or 4WD LOCK 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.
262 STARTING AND OPERATING

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, rotate the transfer case control switch to the desired position.
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. Rotate the transfer case control switch to the desired position.
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
Procedure are not satisfied prior to attempting the shift,
then the desired position indicator light will flash con-
tinuously 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.
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.
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STARTING AND OPERATING 263

The limited-slip differential is especially helpful during
slippery 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 mo-
mentary application of the parking brake may be necessary
to gain maximum traction.
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).
264 STARTING AND OPERATING

NOTE:
•Increased noise levels at the end of the steering wheel
travel are considered normal and do not indicate that
there is a problem with the power steering system.
• Upon initial start-up in cold weather, the power steering
pump may make noise for a short amount of time. This
is due to the cold, thick fluid in the steering system. This
noise should be considered normal, and it does not in
any way damage the steering system.
CAUTION!
Prolonged operation of the steering system at the end
of the steering wheel travel will increase the steering
fluid temperature and it should be avoided when
possible. Damage to the power steering pump may
occur.
Power Steering Fluid Check
Checking the power steering fluid level at a defined service
interval is not required. The fluid should only be checked
if a leak is suspected, abnormal noises are apparent,
and/or the system is not functioning as anticipated. Check fluid level when the engine is cold and off. Coordinate
inspection efforts through an authorized dealer.
CAUTION!
Do not use chemical flushes in your power steering
system as the chemicals can damage your power steer-
ing components. Such damage is not covered by the
New Vehicle Limited Warranty.
WARNING!
Fluid level should be checked on a level surface and
with the engine off to prevent injury from moving
parts and to ensure accurate fluid level reading. Do not
overfill. Use only manufacturer’s recommended power
steering fluid.
If necessary, add fluid to restore to the proper indicated
level. With a clean cloth, wipe any spilled fluid from all
surfaces. Refer to “Fluids And Lubricants” in “Technical
Specifications” for further information.
SPEED CONTROL
When engaged, the Speed Control takes over accelerator
operations at speeds greater than 25 mph (40 km/h).
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