2020 Ram 3500 suspension

270STARTING 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 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 application
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.

WARNING!
Winch cables are under high tension when in
use and can become a projectile if they fail.
Never stand over or straddle the winch cable.
Never jerk or overload the winch cable. Never
stand in front of the vehicle while winching.
Failure to follow these instructions can result
in serious or fatal injury.
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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284STARTING AND OPERATING
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.
When the brakes are overheated.
When the driver door is open at low speed.
When the driver seat belt is unbuckled at low
speed.
Electronic Stability Control (ESC) Full Off
mode is active.
TO ACTIVATE/DEACTIVATE
Push and release the Adaptive Cruise Control
(ACC) on/off button. The ACC menu in the
instrument cluster displays “ACC Ready.”

Adaptive Cruise Control Ready
To turn the system off, push and release the
Adaptive Cruise Control (ACC) on/off button
again. At this time, the system will turn off and
the instrument cluster display will show
“Adaptive Cruise Control (ACC) Off.”

Adaptive Cruise Control Off

WARNING!
Leaving the Adaptive Cruise Control (ACC)
system on when not in use is dangerous. You
could accidentally set the system or cause it
to go faster than you want. You could lose
control and have a collision. Always leave the
system off when you are not using it.

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324STARTING AND OPERATING
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
allowable 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
components in the system with the lowest load
carrying capacity (axle, springs, tires or wheels).
Heavier axles or suspension components
sometimes 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.
RIM SIZE
This is the rim size that is appropriate for the tire
size listed.
INFLATION PRESSURE
This is the cold tire inflation pressure for your
vehicle for all loading conditions up to full
GAWR.
CURB WEIGHT
The curb weight of a vehicle is defined as the
total weight of the vehicle with all fluids,
including vehicle fuel, at full capacity
conditions, and with no occupants or cargo
loaded into the vehicle. The front and rear curb
weight values are determined by weighing your
vehicle on a commercial scale before any
occupants or cargo are added.
LOADING
The actual total weight and the weight of the
front and rear of your vehicle at the ground can
best be determined by weighing it when it is
loaded and ready for operation.

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STARTING AND OPERATING327

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.
5

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328STARTING AND OPERATING
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.
Gooseneck Hitch
The gooseneck hitch employs a pivoted
coupling arm which attaches to a ball mounted
in the bed of a pickup truck. The coupling arm
connects to the hitch mounted over the rear
axle in the truck bed.
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

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STARTING AND OPERATING331
(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)
5

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336STARTING AND OPERATING
TOWING TIPS
Before setting out on a trip, practice turning,
stopping, and backing up the trailer in an area
located away from heavy traffic.
Automatic Transmission
The DRIVE range can be selected when towing.
The transmission controls include a drive
strategy to avoid frequent shifting when towing.
However, if frequent shifting does occur while in
DRIVE, select TOW/HAUL mode or select a lower
gear range (using the Electronic Range Select
[ERS] shift control).
NOTE:
Using TOW/HAUL mode or selecting a lower
gear range (using the ERS shift control) while
operating the vehicle under heavy loading
conditions will improve performance and
extend transmission life by reducing excessive
shifting and heat build-up. This action will also
provide better engine braking.
Tow/Haul Mode
To reduce potential for automatic transmission
overheating, activate TOW/HAUL mode when
driving in hilly areas, or select a lower gear
range (using the Electronic Range Select [ERS]
shift control) on more severe grades.
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
information.
NOTE:
The vehicle must remain in the engine running
position while attaching a trailer for proper
leveling of the air suspension system.

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STARTING AND OPERATING339
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
D
RIVE 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
instructions.

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 OK5

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