suspension Ram 2500 2020 User Guide

264STARTING AND OPERATING
Check threaded fasteners for looseness,
particularly on the chassis, drivetrain compo -
nents, steering, and suspension. 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.
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 imbal-
ance 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
driving and cornering, the limited-slip unit
performs similarly 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 slippery driving conditions. With both
rear wheels on a slippery surface, a slight appli -
cation of the accelerator will supply maximum
traction. When starting with only one rear wheel
on an excessively slippery surface, slight
momentary application of the parking brake
may be necessary to gain maximum traction. Care should be taken to avoid sudden accelera-
tions 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.
WINCH USAGE — POWER WAGON ONLY (IF
EQUIPPED)
Things To Know Before Using Your Winch
General Winch Information
Your vehicle is equipped with an electric vehicle
recovery winch. This winch uses the electrical
power from the vehicle charging system to
power a motor that winds the winch rope onto
the winch drum via planetary gear reduction. By
nature, a winch is capable of generating very
high forces and should be used with care. Do
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.
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.

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STARTING AND OPERATING277
Adaptive Cruise Control (ACC) Operation
The speed control buttons (located on the right
side of the steering wheel) operate the ACC
system.
Adaptive Cruise Control Buttons

NOTE:
Any chassis/suspension or tire size modifica -
tions to the vehicle will affect the performance
of the Adaptive Cruise Control and Forward
Collision Warning System.
Activating Adaptive Cruise Control (ACC)
You can only engage ACC if the vehicle speed is
above 0 mph (0 km/h).
The minimum set speed for the ACC system is
20 mph (32 km/h).
When the system is turned on and in the ready
state, the instrument cluster display will read
“ACC Ready.”
When the system is off, the instrument cluster
display will read “Adaptive Cruise Control (ACC)
Off.”
NOTE:
You cannot engage ACC under the following
conditions:
When in Four-Wheel Drive Low.
When you apply the brakes.
When the parking brake is applied.
When the automatic transmission is in PARK,
REVERSE or NEUTRAL.
When the vehicle speed is outside of the
speed range.
You should switch off the ACC system:
When driving in fog, heavy rain, heavy
snow, sleet, heavy traffic, and complex
driving situations (i.e., in highway construc
-
tion zones).
When entering a turn lane or highway off
ramp; when driving on roads that are
winding, icy, snow-covered, slippery, or
have steep uphill or downhill slopes.
When towing a trailer up or down steep
slopes.
When circumstances do not allow safe
driving at a constant speed.
WARNING! (Continued)
1 — Adaptive Cruise Control On/Off Button
2 — Distance Button
3 — RES (+)
4 — SET (-)
5 — CANCEL
6 — Normal (Fixed Speed) Cruise Control On/Off
Button
5

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STARTING AND OPERATING317
3. Stop filling the DEF tank immediately when
any of the following happen: DEF stops
flowing from the fill bottle into the DEF tank,
DEF splashes out the filler neck, or a DEF
pump nozzle automatically shuts off.
4. Reinstall cap onto DEF tank.
Filling The Def Tank In Cold Climates
Since DEF will begin to freeze at 12°F (-11°C),
your vehicle is equipped with an automatic DEF
heating system. This allows the DEF injection system to operate properly at temperatures
below 12°F (-11°C). If your vehicle is not in
operation for an extended period of time with
temperatures below 12°F (-11°C), the DEF in
the tank may freeze. If the tank is overfilled and
freezes, it could be damaged. Therefore, do not
overfill the DEF tank.
Extra care should be taken when filling with
portable containers to avoid overfilling. Note the
level of the DEF gauge in your instrument cluster.
You may safely add a maximum of 2 Gallons
(7.5 Liters) of DEF from portable containers
when your DEF gauge is reading ½ full.
VEHICLE LOADING
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total permissible weight of your
vehicle including driver, passengers, vehicle,
options and cargo. The label also specifies
maximum capacities of front and rear axle
systems (GAWR). Total load must be limited so
GVWR and front and rear GAWR are not
exceeded.
Payload
The payload of a vehicle is defined as the allow
-
able load weight a truck can carry, including the
weight of the driver, all passengers, options and
cargo.
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum permissible load on
the front and rear axles. The load must be
distributed in the cargo area so that the GAWR
of each axle is not exceeded.
Each axle GAWR is determined by the compo -
nents in the system with the lowest load
carrying capacity (axle, springs, tires or wheels).
Heavier axles or suspension components some -
times specified by purchasers for increased
durability does not necessarily increase the
vehicle's GVWR.
Tire Size
The tire size on the Vehicle Certification Label
represents the actual tire size on your vehicle.
Replacement tires must be equal to the load
capacity of this tire size.
Never add anything other than DEF to the
tank – especially any form of hydrocarbon
such as diesel fuel, fuel system additives,
gasoline, or any other petroleum-based
product. Even a very small amount of these,
less than 100 parts per million or less than
1 oz. per 78 Gallons (295 Liters) will
contaminate the entire DEF system and will
require replacement. If owners use a
container, funnel or nozzle when refilling
the tank, it should either be new or one that
is has only been used for adding DEF.
Mopar provides an attachable nozzle with
its DEF for this purpose.
CAUTION! (Continued)
5

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320STARTING AND OPERATING
distributing (load equalizing) hitch are recom -
mended for heavier Tongue Weights (TW) and
may be required depending on vehicle and
trailer configuration/loading to comply with
GAWR requirements.

With Weight-Distributing Hitch (Correct) Without Weight-Distributing Hitch (Incorrect)
Improper Adjustment Of Weight-Distributing Hitch (Incorrect)
Recommended Distribution Hitch Adjustment
Towing With 2500/3500 Air Suspension

1. Position the truck to be ready to connect to
the trailer (do not connect the trailer).

NOTE:
Normal Ride Height (NRH) or Alternate Trailer
Height (ATH) can be used. The vehicle must
remain in the engine running position while
attaching a trailer for proper leveling of the air
suspension system. It may not be possible to
enter Alternate Trailer Height (ATH) while lightly
loaded.
2. Measure the height of the top of the front wheel opening on the fender to ground, this
is height H1.
3. Attach the trailer to the vehicle without the weight distribution bars connected.
4. Measure the height of the top of the front wheel opening on the fender to ground, this
is height H2.
WARNING!
An improperly adjusted weight distributing
hitch system may reduce handling, stability
and braking performance and could result
in a collision.
Weight distributing systems may not be
compatible with surge brake couplers.
Consult with your hitch and trailer manufac -
turer or a reputable Recreational Vehicle
dealer for additional information.

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STARTING AND OPERATING321
5. Install and adjust the tension in the weight
distributing bars per the manufacturers’
recommendations so that the height of the
front fender is approximately (H2-H1)/
2+H1 (about 1/2 the difference between
H2 and H1 above normal ride height [H1]).
6. Perform a visual inspection of the trailer and weight distributing hitch to confirm
manufacturers’ recommendations have
been met.
NOTE:
For all towing conditions, we recommend towing
with TOW/HAUL mode engaged. Towing With All Other 2500/3500 (Non-Air
Suspension)

1. Position the truck to be ready to connect to
the trailer (do not connect the trailer).

2. Measure the height of the top of the front wheel opening on the fender to ground, this
is height H1.
3. Attach the trailer to the vehicle without the weight distribution bars connected.
4. Measure the height of the top of the front wheel opening on the fender to ground, this
is height H2.
5. Install and adjust the tension in the weight distributing bars per the manufacturers’
recommendations so that the height of the
front fender is approximately (H2-H1)/
2+H1 (about 1/2 the difference between
H2 and H1 above normal ride height [H1]).
6. Perform a visual inspection of the trailer and weight distributing hitch to confirm
manufacturers’ recommendations have
been met. NOTE:
For all towing conditions, we recommend towing
with TOW/HAUL mode engaged.
Fifth-Wheel Hitch
The fifth-wheel hitch is a special high platform
with a coupling that mounts over the rear axle of
the tow vehicle in the truck bed. It connects a
vehicle and fifth-wheel trailer with a coupling
king pin.
Your truck may be equipped with a fifth wheel
hitch option. Refer to the separately provided
fifth wheel hitch safety, care, assembly, and
operating instructions.
Measurement
Example Example 2500/
3500 Height (mm)
H1 1030
H2 1058
H2-H1 28
(H2-H1)/2 14
(H2-H1)/2 + H1 1044
Measurement
Example Example 2500/
3500 Height (mm)
H1 1030
H2 1058
H2-H1 28
(H2-H1)/2 14
(H2-H1)/2 + H1 1044
5

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324STARTING AND OPERATING
(Continued)
Towing Requirements — Tires
Do not attempt to tow a trailer while using a
compact spare tire.
Do not drive more than 50 mph (80 km/h) when towing while using a full size spare tire.
Proper tire inflation pressures are essential
to the safe and satisfactory operation of your
vehicle. Refer to “Tires” in “Servicing And
Maintenance” for proper tire inflation proce -
dures.
Check the trailer tires for proper tire inflation
pressures before trailer usage.
Check for signs of tire wear or visible tire
damage before towing a trailer. Refer to
“Tires” in “Servicing And Maintenance” for
the proper inspection procedure.
When replacing tires, refer to “Tires” in
“Servicing And Maintenance” for the proper
tire replacement procedures. Replacing tires
with a higher load carrying capacity will not
increase the vehicle's GVWR and GAWR
limits.
Towing Requirements — Trailer Brakes
Do not interconnect the hydraulic brake
system or vacuum system of your vehicle
with that of the trailer. This could cause inad -
equate braking and possible personal injury.
An electronically actuated trailer brake
controller is required when towing a trailer
with electronically actuated brakes. When
towing a trailer equipped with a hydraulic
surge actuated brake system, an electronic
brake controller is not required.
Trailer brakes are recommended for trailers
over 1,000 lbs (453 kg) and required for
trailers in excess of 2,000 lbs (907 kg).
When hauling cargo or towing a trailer, do
not overload your vehicle or trailer. Over -
loading can cause a loss of control, poor
performance or damage to brakes, axle,
engine, transmission, steering, suspension,
chassis structure or tires.
Safety chains must always be used
between your vehicle and trailer. Always
connect the chains to the hook retainers of
the vehicle hitch. Cross the chains under
the trailer tongue and allow enough slack
for turning corners.
Vehicles with trailers should not be parked
on a grade. When parking, apply the
parking brake on the tow vehicle. Put the
tow vehicle transmission in PARK. For
four-wheel drive vehicles, make sure the
transfer case is not in NEUTRAL. Always,
block or "chock" the trailer wheels.
GCWR must not be exceeded.
WARNING! (Continued)
Total weight must be distributed between
the tow vehicle and the trailer such that the
following four ratings are not exceeded :
GVWR
GTW
GAWR
Tongue weight rating for the trailer
hitch utilized.
WARNING! (Continued)

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STARTING AND OPERATING329
Speed Control — If Equipped
Do not use on hilly terrain or with heavy
loads.
When using the Speed Control, if you experi -
ence speed drops greater than 10 mph
(16 km/h), disengage until you can get back
to cruising speed.
Use Speed Control in flat terrain and with
light loads to maximize fuel efficiency.
Cooling System
To reduce potential for engine and transmission
overheating, take the following actions:
City Driving
In city traffic — while stopped, place the trans -
mission in NEUTRAL, but do not increase
engine idle speed.
Highway Driving
Reduce speed.
Temporarily turn off air conditioning.
Air Suspension System
To aid in attaching/detaching the trailer from
the vehicle, the air suspension system can be
used. Refer to “Air Suspension System” in “Starting And Operating” for further informa
-
tion.
NOTE:
The vehicle must remain in the engine running
position while attaching a trailer for proper
leveling of the air suspension system.
SNOWPLOW
Snowplow Prep Packages are available as a
factory installed option. These packages
include components necessary to equip your
vehicle with a snowplow.
NOTE:
Before installation of a snowplow it is highly
recommended that the owner/installer obtain
and follow the recommendations contained
within the current Body Builders Guide. See
your authorized dealer, installer or snowplow
manufacturer for this information. There are
unique electrical systems that must be
connected to properly ensure operator safety
and prevent overloading vehicle systems.
Before Plowing
Check the hydraulic system for leaks and
proper fluid level.
Check the mounting bolts and nuts for proper
tightness.
Check the runners and cutting edge for
excessive wear. The cutting edge should be
¼ to ½ inches (6 cm to 1.2 cm) above ground
in snow plowing position.
Check that snowplow lighting is connected
and functioning properly.
WARNING!
Attaching a snowplow to this vehicle could
adversely affect performance of the airbag
system in a collision. Do not expect that the
airbag will perform as described earlier in this
manual.
CAUTION!
The “Lamp Out” indicator could illuminate if
exterior lamps are not properly installed.
5

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STARTING AND OPERATING331
RECREATIONAL TOWING (BEHIND MOTORHOME, ETC.)
Towing This Vehicle Behind Another Vehicle
NOTE:
When towing your vehicle, always follow
applicable state and provincial laws. Contact
state and provincial Highway Safety offices
for additional details.
Vehicles equipped with air suspension must
be placed in Transport mode before tying
them down (from the body) on a trailer or
flatbed truck. Refer to “Air Suspension – If
Equipped” for more information. If the
vehicle cannot be placed in Transport mode (for example, engine will not run), tie-downs
must be fastened to the axles (not to the
body). Failure to follow these instructions
may cause fault codes to be set and/or
cause loss of proper tie-down tension.Recreational Towing — Two-Wheel Drive
Models
DO NOT flat tow this vehicle. Damage to the
drivetrain will result.
Recreational towing (for two-wheel drive
models) is allowed
ONLY if the rear wheels are OFF
the ground. This may be accomplished
using a tow dolly or vehicle trailer. If using a tow
dolly, follow this procedure:
NOTE:
If vehicle is equipped with air suspension,
ensure the vehicle is set to Normal Ride Height.

1. Properly secure the dolly to the tow vehicle, following the dolly manufacturer's instruc -
tions.

2. Drive the rear wheels onto the tow dolly.
Towing Condition Wheels OFF The
Ground Two-Wheel Drive
Models Four-Wheel Drive Models
Flat Tow
NONENOT ALLOWED See Instructions
Automatic transmission in PARK
Transfer case in NEUTRAL (N)
Tow in forward direction
Dolly Tow Front
NOT ALLOWED NOT ALLOWED
Rear OK NOT ALLOWED
On Trailer ALLOK OK
5

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STARTING AND OPERATING333
Shifting Into (N) NEUTRAL
Use the following procedure to prepare your
vehicle for recreational towing.

1. Bring the vehicle to a complete stop on
level ground, with the engine running.
Firmly apply the parking brake.

2. Shift the transmission to NEUTRAL. NOTE:
If vehicle is equipped with air suspension,
ensure the vehicle is set to Normal Ride Height.
3. Press and hold the brake pedal.
4. Shift the transfer case into N (Neutral):
With manual shift transfer case, shift the
transfer case lever into N (Neutral)
With electronic shift transfer case, push and hold the transfer case N (Neutral)
button. Some models have a small,
recessed “N” button (at the center of the
transfer case switches) that must be
pushed using a ballpoint pen or similar
object. Other models have a rectangular
N (Neutral) switch, below the rotary
transfer case control knob. The N
(Neutral) indicator light will blink while
the shift is in progress. The light will stop
blinking (stay on solid) when the shift to N
(Neutral) is complete. After the shift is
completed and the N (Neutral) light stays
on, release the N (Neutral) button.
5. Release the parking brake.
6. Shift the transmission into REVERSE. 7. Release the brake pedal for five seconds
and ensure that there is no vehicle move-
ment.
8. Repeat steps 6 and 7 with automatic trans -
mission in DRIVE.
9. Shift the transmission to NEUTRAL. Firmly apply the parking brake. Turn off the engine.
For vehicles with Keyless Enter-N-Go, push
and hold the ENGINE START/STOP button
until the engine shuts off.
10. Shift the transmission into PARK. On 8-speed transmissions the shifter will auto -
matically select PARK when the engine is
turned off.
11. Turn the ignition to the OFF mode, then cycle the ignition to the RUN mode and back
to the OFF mode. Remove the key fob from
the ignition.
12. Attach the vehicle to the tow vehicle using a suitable tow bar.
13. Release the parking brake.
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 driveshafts from the
powertrain, and will allow the vehicle to roll,
even if the automatic transmission is in PARK.
The parking brake should always be applied
when the driver is not in the vehicle.
CAUTION!
It is necessary to follow these steps to be
certain that the transfer case is fully in
NEUTRAL (N) before recreational towing to
prevent damage to internal parts.
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334STARTING AND OPERATING
NOTE:
With electronic shift transfer case:
Steps 2 through 3 are requirements that
must be met before pushing the N (Neutral)
button, and must continue to be met until the
shift has been completed. If any of these
requirements are not met before pushing the
N (Neutral) button or are no longer met
during the shift, the N (Neutral) indicator light
will flash continuously until all requirements
are met or until the N (Neutral) button is
released.
The ignition must be in the ON/RUN mode for
a shift to take place and for the position indi -
cator lights to be operable. If the ignition is
not in the ON/RUN mode, the shift will not
take place and no position indicator lights will
be on or flashing.
A flashing N (Neutral) position indicator light
indicates that shift requirements have not
been met.
If the vehicle is equipped with air suspension,
the engine should be started and left running
for a minimum of 60 seconds (with all the
doors closed) at least once every 24 hours. This process allows the air suspension to
adjust the vehicle’s ride height to compen
-
sate for temperature effects.
Shifting Out Of (N) NEUTRAL
Use the following procedure to prepare your
vehicle for normal usage:

1. Bring the vehicle to a complete stop,
leaving it connected to the tow vehicle.

2. Firmly apply the parking brake.
3. Press and hold the brake pedal.
4. Start the engine. Shift the transmission into NEUTRAL.
With manual shift transfer case, shift the transfer case lever to the desired posi -
tion.
With electronic shift transfer case with rotary selector switch, push and hold the
transfer case N (Neutral) button until the
N (Neutral) indicator light turns off. After
the N (Neutral) indicator light turns off,
release the N (Neutral) button. After the
N (Neutral) button has been released, the
transfer case will shift to the position indi -
cated by the selector switch.
With electronic shift transfer case with push-button selector switch, push and
hold the switch for the desired transfer
case position, until the N (Neutral) indi -
cator light turns off and the desired posi -
tion indicator light turns on.
NOTE:
When shifting out of transfer case N (Neutral),
turning the engine OFF is not required, but may
be helpful to avoid gear clash. With the 8-speed
automatic transmission, the engine must
remain running, since turning the engine OFF
will shift the transmission to PARK (and the
transmission must be in NEUTRAL for the
transfer case to shift out of NEUTRAL).
5. Turn the engine off. Shift automatic trans -
mission into PARK. On 8-speed transmis -
sions the shifter will automatically select
PARK when the engine is turned off.
6. Release the brake pedal.
7. Disconnect vehicle from the tow vehicle.
8. Start the engine.
9. Press and hold the brake pedal.

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