2018 Ram 3500 Rear end

The locking axles are controlled by the axle locker switch.
The switch has three positions:
•AXLE UNLOCK – the front and rear axles are unlocked
• REAR LOCK – the rear axle is locked
• FRONT/REAR LOCK – the front and rear axles are
locked
Under normal driving conditions, the switch should be left
in the AXLE UNLOCK position.
NOTE: Even when the axles are in the AXLE UNLOCK
position, the limited slip differential in the rear axle still
provides torque biasing capability for moderate low trac-
tion environments.
During the command to lock the axle, the indicator light
will flash until the axle is locked. After the lock command
has been successfully executed, the light will remain on
solid.
To lock the rear axle, place the vehicle in 4LO. Refer to
“Four Wheel Drive Operation” in “Starting And Operat-
ing” for further information. Move the axle locker switch
position to REAR LOCK while traveling less than 3 mph
(5 km/h). The RR indicator light will remain on when the
rear axle is locked. NOTE:
Left to right wheel speed difference may be neces-
sary to allow the axle to fully lock. If the indicator light is
flashing after placing the switch in the REAR LOCK or
FRONT/REAR LOCK position, drive the vehicle in a turn
or on loose gravel to expedite the locking action.
WARNING!
Do not use the locked axle position for normal driving.
A locked front axle is intended for off-road driving
only. Locking the front axle during on-road driving
will reduce the steering ability. This could cause a
collision and you may be seriously injured.
To lock the front axle; move the axle locker switch to
FRONT/REAR LOCK while traveling less than 3 mph
(5 km/h). The indicator light will be solid when the front
axle is locked.
NOTE: The rear axle must be locked before the front axle
will lock.
To unlock the front axle; move the axle locker switch to
REAR LOCK. The FRONT/REAR LOCK indicator light
will go out when the axle is unlocked.
360 STARTING AND OPERATING

After Driving Off-Road
Off-road operation puts more stress on your vehicle than
does most on-road driving. After going off-road, it is
always a good idea to check for damage. That way you can
get any problems taken care of right away and have your
vehicle ready when you need it.
•Completely inspect the underbody of your vehicle.
Check tires, body structure, steering, suspension, and
exhaust system for damage.
• Inspect the radiator for mud and debris and clean as
required.
• Check threaded fasteners for looseness, particularly on
the chassis, drivetrain components, steering, and sus-
pension. Retighten them, if required, and torque to the
values specified in the Service Manual.
• Check for accumulations of plants or brush. These things
could be a fire hazard. They might hide damage to fuel
lines, brake hoses, axle pinion seals, and propeller shafts.
• After extended operation in mud, sand, water, or similar
dirty conditions, have the radiator, fan, brake rotors,
wheels, brake linings, and axle yokes inspected and
cleaned as soon as possible.
WARNING!
Abrasive material in any part of the brakes may cause
excessive wear or unpredictable braking. You might
not have full braking power when you need it to
prevent a collision. If you have been operating your
vehicle in dirty conditions, get your brakes checked
and cleaned as necessary.
• If you experience unusual vibration after driving in
mud, slush or similar conditions, check the wheels for
impacted material. Impacted material can cause a wheel
imbalance and freeing the wheels of it will correct the
situation.
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
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STARTING AND OPERATING 375

PARKSENSE REAR PARK ASSIST — IF EQUIPPED
The ParkSense Rear Park Assist system provides visual and
audible indications of the distance between the rear fascia
and a detected obstacle when backing up, e.g. during a
parking maneuver. Refer to “ParkSense System Usage
Precautions” in this section for limitations of this system
and recommendations.
ParkSense will retain the last system state (enabled or
disabled) from the last ignition cycle when the ignition is
changed to the ON/RUN position.
ParkSense can be active only when the gear selector is in
REVERSE. If ParkSense is enabled at this gear selector
position, the system will remain active until the vehicle
speed is increased to approximately 7 mph (11 km/h) or
above. When in REVERSE and above the system’s operat-
ing speed, a warning will appear within the instrument
cluster display indicating the vehicle speed is too fast. The
system will become active again if the vehicle speed is
decreased to speeds less than approximately 6 mph
(9 km/h).
ParkSense Sensors
The four ParkSense sensors, located in the rear fascia/
bumper, monitor the area behind the vehicle that is withinthe sensors’ field of view. The sensors can detect obstacles
from approximately 18 inches (45 cm) up to 79 inches
(200 cm) from the rear fascia/bumper in the horizontal
direction, depending on the location, type and orientation of
the obstacle.
ParkSense Warning Display
The ParkSense Warning screen is located within the instru-
ment cluster display. It provides visual warnings to indi-
cate the distance between the rear fascia/bumper and the
detected obstacle. Refer to “Instrument Cluster Display” in
“Getting To Know Your Instrument Panel” for further
information.
The ParkSense Warning screen will only be displayed if
“Sound and Display” is selected.
NOTE:
This feature can be programmed through the
Uconnect system. Refer to “Uconnect Settings” in “Multi-
media” for further information.
ParkSense Display
When the vehicle is in REVERSE, the warning display will
turn on indicating the system status.
398 STARTING AND OPERATING

•Clean the ParkSense sensors regularly, taking care not to
scratch or damage them. The sensors must not be
covered with ice, snow, slush, mud, dirt or debris.
Failure to do so can result in the system not working
properly. The ParkSense system might not detect an
obstacle behind the fascia/bumper, or it could provide a
false indication that an obstacle is behind the fascia/
bumper.
• Ensure the ParkSense system is OFF if objects such as
bicycle carriers, trailer hitches, etc., are placed within 18
inches (45 cm) from the rear fascia/bumper while driv-
ing the vehicle. Failure to do so can result in the system
misinterpreting a close obstacle as a sensor problem,
causing the PARKSENSE UNAVAILABLE SERVICE
REQUIRED message to appear in the instrument cluster
display.
• On vehicles equipped with a tailgate, ParkSense should
be disabled when the tailgate is in the lowered or open
position and the vehicle is in REVERSE. A lowered
tailgate could provide a false indication that an obstacle
is behind the vehicle.WARNING!
•Drivers must be careful when backing up even when
using ParkSense. Always check carefully behind
your vehicle, look behind you, and be sure to check
for pedestrians, animals, other vehicles, obstructions,
and blind spots before backing up. You are respon-
sible for safety and must continue to pay attention to
your surroundings. Failure to do so can result in
serious injury or death.
• Before using ParkSense, it is strongly recommended
that the ball mount and hitch ball assembly is
disconnected from the vehicle when the vehicle is
not used for towing. Failure to do so can result in
injury or damage to vehicles or obstacles because the
hitch ball will be much closer to the obstacle than the
rear fascia when the loudspeaker sounds the con-
tinuous tone. Also, the sensors could detect the ball
mount and hitch ball assembly, depending on its size
and shape, giving a false indication that an obstacle
is behind the vehicle.
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STARTING AND OPERATING 403

CAUTION!
•ParkSense is only a parking aid and it is unable to
recognize every obstacle, including small obstacles.
Parking curbs might be temporarily detected or not
detected at all. Obstacles located above or below the
sensors will not be detected when they are in close
proximity.
• The vehicle must be driven slowly when using
ParkSense in order to be able to stop in time when an
obstacle is detected. It is recommended that the
driver looks over his/her shoulder when using
ParkSense.
PARKSENSE FRONT AND REAR PARK ASSIST —
IF EQUIPPED
The ParkSense Park Assist system provides visual and
audible indications of the distance between the rear and/or
front fascia and a detected obstacle when backing up or
moving forward, e.g. during a parking maneuver. Refer to
“ParkSense System Usage Precautions” in this section for
limitations of this system and recommendations. ParkSense will retain the last system state (enabled or
disabled) from the last ignition cycle when the ignition is
changed to the ON/RUN position.
ParkSense can be active only when the gear selector is in
REVERSE or DRIVE. If ParkSense is enabled at one of these
gear selector positions, the system will remain active until
the vehicle speed is increased to approximately 7 mph
(11 km/h) or above. A warning will appear in the instru-
ment cluster display indicating the vehicle is above
ParkSense operating speed. The system will become active
again if the vehicle speed is decreased to speeds less than
approximately 6 mph (9 km/h).
ParkSense Sensors
The four ParkSense sensors, located in the rear fascia/
bumper, monitor the area behind the vehicle that is within
the sensors’ field of view. The sensors can detect obstacles
from approximately 18 inches (45 cm) up to 79 inches
(200 cm) from the rear fascia/bumper in the horizontal
direction, depending on the location, type and orientation
of the obstacle.
404 STARTING AND OPERATING

The six ParkSense sensors, located in the front fascia/
bumper, monitor the area in front of the vehicle that is
within the sensors’ field of view. The sensors can detect
obstacles from approximately 12 inches (30 cm) up to 47
inches (120 cm) from the front fascia/bumper in the
horizontal direction, depending on the location, type and
orientation of the obstacle.
ParkSense Warning Display
The ParkSense Warning screen is located within the instru-
ment cluster display. It provides visual warnings to indi-
cate the distance between the rear fascia/bumper and/or
front fascia/bumper and the detected obstacle. Refer to
“Instrument Cluster Display” in “Getting To Know Your
Instrument Panel” for further information.
The ParkSense Warning screen will only be displayed if
“Sound and Display” is selected.
NOTE:This feature can be programmed through the
Uconnect system. Refer to “Uconnect Settings” in “Multi-
media” for further information.
ParkSense Display
The warning display will turn on indicating the system
status when the vehicle is in REVERSE or when the vehicle
is in DRIVE and an obstacle has been detected.
The system will indicate a detected obstacle by showing a
single arc in the left and/or right rear regions based on the
obstacle’s distance and location relative to the vehicle.
If an obstacle is detected in the left and/or right rear
region, the display will show a single arc in the left and/or
right rear region and the system will produce a tone. As the
vehicle moves closer to the obstacle, the display will show
the single arc moving closer to the vehicle and the tone will
change from a single 1/2 second tone to slow, to fast, to
continuous.
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STARTING AND OPERATING 405

a faulted condition, the instrument cluster display will
display aPARKSENSE UNAVAILABLE WIPE REAR SEN-
SORS, PARKSENSE UNAVAILABLE WIPE FRONT SEN-
SORS orPARKSENSE UNAVAILABLE SERVICE RE-
QUIRED pop up message for five seconds. After five
seconds, a vehicle graphic will be displayed with UN-
AVAILABLE at either the front or rear sensor location
depending on where the fault is detected. The system will
continue to provide arc alerts for the side that is function-
ing properly. These arc alerts will interrupt the
PARKSENSE UNAVAILABLE WIPE REAR SENSORS,
PARKSENSE UNAVAILABLE WIPE FRONT SENSORS ,
or PARKSENSE UNAVAILABLE SERVICE REQUIRED
messages if an object is detected within the five second
pop-up duration. The vehicle graphic will remain dis-
played for as long as the vehicle is in REVERSE.
Refer to “Instrument Cluster Display” in “Getting To Know
Your Instrument Panel” for further information.
If PARKSENSE UNAVAILABLE WIPE REAR SENSORS
or PARKSENSE UNAVAILABLE WIPE FRONT SEN-
SORS appears in the instrument cluster display make sure
the outer surface and the underside of the rear fascia/
bumper and/or front fascia/bumper is clean and clear of snow, ice, mud, dirt or other obstruction and then cycle the
ignition. If the message continues to appear see your
authorized dealer.
If the
PARKSENSE UNAVAILABLE SERVICE RE-
QUIRED message appears in the instrument cluster dis-
play, see your authorized dealer.
Cleaning The ParkSense System
Clean the ParkSense sensors with water, car wash soap and
a soft cloth. Do not use rough or hard cloths. Do not scratch
or poke the sensors. Otherwise, you could damage the
sensors.
ParkSense System Usage Precautions
NOTE:
• Ensure that the front and rear bumper are free of snow,
ice, mud, dirt and debris to keep the ParkSense system
operating properly.
• Jackhammers, large trucks, and other vibrations could
affect the performance of ParkSense.
• When you turn Front or Rear ParkSense off, the instru-
ment cluster display will read “FRONT PARKSENSE
OFF” or “REAR PARKSENSE OFF.” Furthermore, once
408 STARTING AND OPERATING

you turn Front or Rear ParkSense off, it remains off until
you turn it on again, even if you cycle the ignition key.
• When you move the gear selector to the REVERSE
position and Front or Rear ParkSense is turned off, the
instrument cluster display will show the FRONT
PARKSENSE OFF orREAR PARKSENSE OFF mes-
sage for five seconds, followed by a vehicle graphic with
OFF in the corresponding side. This vehicle graphic
will be displayed for as long as the vehicle is in
REVERSE.
• ParkSense, when on, will reduce the volume of the radio
when it is sounding a tone.
• Clean the ParkSense sensors regularly, taking care not to
scratch or damage them. The sensors must not be
covered with ice, snow, slush, mud, dirt or debris.
Failure to do so can result in the system not working
properly. The ParkSense system might not detect an
obstacle behind or in front of the fascia/bumper, or it
could provide a false indication that an obstacle is
behind or in front of the fascia/bumper.
• Use the ParkSense switch to turn the ParkSense system
off if obstacles such as bicycle carriers, trailer hitches,
etc. are placed within 18 inches (45 cm) from the rear
fascia/bumper. Failure to do so can result in the system misinterpreting a close obstacle as a sensor problem,
causing the “PARKSENSE UNAVAILABLE SERVICE
REQUIRED” message to be appear in the instrument
cluster display.
• On vehicles equipped with a tailgate, ParkSense should
be disabled when the tailgate is in the lowered or open
position. A lowered tailgate could provide a false indi-
cation that an obstacle is behind the vehicle.
WARNING!
•Drivers must be careful when backing up even when
using ParkSense. Always check carefully behind
your vehicle, look behind you, and be sure to check
for pedestrians, animals, other vehicles, obstructions,
and blind spots before backing up. You are respon-
sible for safety and must continue to pay attention to
your surroundings. Failure to do so can result in
serious injury or death.
• Before using ParkSense, it is strongly recommended
that the ball mount and hitch ball assembly is
disconnected from the vehicle when the vehicle is
not used for towing. Failure to do so can result in
injury or damage to vehicles or obstacles because the
(Continued)
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STARTING AND OPERATING 409