tow RAM CHASSIS CAB 2021 Workshop Manual

200STARTING AND OPERATING
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.
The entire vehicle should first be weighed on a
commercial scale to ensure that the GVWR has
not been exceeded. The weight on the front and
rear of the vehicle should then be determined
separately to be sure that the load is properly
distributed over the front and rear axles.
Weighing the vehicle may show that the GAWR
of either the front or rear axle has been
exceeded but the total load is within the
specified GVWR. If so, weight must be shifted
from front to rear or rear to front as appropriate
until the specified weight limitations are met. Store the heavier items down low and be sure
that the weight is distributed equally. Stow all
loose items securely before driving.
Improper weight distributions can have an
adverse effect on the way your vehicle steers
and handles and the way the brakes operate.
TRAILER TOWING
In this section you will find safety tips and
information on limits to the type of towing you
can reasonably do with your vehicle. Before
towing a trailer, carefully review this information
to tow your load as efficiently and safely as
possible.
To maintain the New Vehicle Limited Warranty
coverage, follow the requirements and
recommendations in this manual concerning
vehicles used for trailer towing.
CAUTION!

Do not load your vehicle any heavier than the
GVWR or the maximum front and rear GAWR. If
you do, parts on your vehicle can break, or it
can change the way your vehicle handles.
This could cause you to lose control. Also
overloading can shorten the life of your vehicle.

21_DPF_OM_EN_USC_t.book Page 200

STARTING AND OPERATING201
COMMON TOWING DEFINITIONS
The following trailer towing related definitions
will assist you in understanding the following
information:
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total allowable weight of your
vehicle. This includes driver, passengers, cargo
and tongue weight. The total load must be
limited so that you do not exceed the GVWR
Úpage 199.
Gross Trailer Weight (GTW)
The GTW is the weight of the trailer plus
the weight of all cargo, consumables and
equipment (permanent or temporary) loaded
in or on the trailer in its "loaded and ready for
operation" condition.
The recommended way to measure GTW is to
put your fully loaded trailer on a vehicle scale.
The entire weight of the trailer must be
supported by the scale.
Gross Combination Weight Rating (GCWR)

The GCWR is the total allowable weight of your
vehicle and trailer when weighed in combination.

Gross Axle Weight Rating (GAWR)

The GAWR is the maximum capacity of the front and
rear axles. Distribute the load over the front and rear
axles evenly. Make sure that you do not exceed
either front or rear GAWR
Ú
page 199.

Tongue Weight (TW)
The TW is the downward force exerted on the
hitch ball by the trailer. You must consider this
as part of the load on your vehicle.
Trailer Frontal Area
The frontal area is the maximum height
multiplied by the maximum width of the front
of a trailer.
Trailer Sway Control (TSC)

The TSC can be a mechanical telescoping link that
can be installed between the hitch receiver and the
trailer tongue that typically provides adjustable
friction associated with the telescoping motion to
dampen any unwanted trailer swaying motions
while traveling.

If equipped, the electronic TSC recognizes a
swaying trailer and automatically applies
individual wheel brakes and/or reduces engine
power to attempt to eliminate the trailer sway.
Weight-Carrying Hitch

A weight-carrying hitch supports the trailer tongue
weight, just as if it were luggage located at a hitch
ball or some other connecting point of the vehicle.
These kinds of hitches are commonly used to tow
small and medium sized trailers.

WARNING!
If the gross trailer weight is 5,000 lbs
(2,267 kg) or more, it is recommended to use
a weight-distributing hitch to ensure stable
handling of your vehicle. If you use a standard
weight-carrying hitch, you could lose control
of your vehicle and cause a collision.
WARNING!
It is important that you do not exceed the
maximum front or rear GAWR. A dangerous
driving condition can result if either rating
is exceeded. You could lose control of the
vehicle and have a collision.
4

21_DPF_OM_EN_USC_t.book Page 201

202STARTING AND OPERATING
Weight-Distributing Hitch

A weight-distributing hitch system works by
applying leverage through spring (load) bars.
They are typically used for heavier loads to
distribute trailer tongue weight to the tow
vehicle's front axle and the trailer axle(s). When
used in accordance with the manufacturer's
directions, it provides for a more level ride,
offering more consistent steering and brake
control, thereby enhancing towing safety.
The addition of a friction/hydraulic sway control
also dampens sway caused by traffic and
crosswinds and contributes positively to tow
vehicle and trailer stability. Trailer Sway Control
(TSC) and a weight distributing (load equalizing)
hitch are recommended for heavier Tongue
Weights (TW) and may be required depending
on vehicle and trailer configuration/loading to
comply with GAWR requirements.
Without Weight-Distributing Hitch (Incorrect)With Weight-Distributing Hitch (Correct)
Improper Adjustment Of Weight-Distributing Hitch (Incorrect)
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.

21_DPF_OM_EN_USC_t.book Page 202

STARTING AND OPERATING203
Recommended Distribution Hitch Adjustment

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.

Measuring Height (H)

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 1,030
H2 1,058
H2-H1 28
(H2-H1)/2 14
(H2-H1)/2 + H1 1,044
4

21_DPF_OM_EN_USC_t.book Page 203

204STARTING AND OPERATING
TRAILER HITCH TYPE AND MAXIMUM TRAILER WEIGHT
The following chart provides the industry standard for the maximum trailer weight a given trailer hitch class can tow and should be used to assist you
in selecting the correct trailer hitch for your intended towing condition.
Trailer Hitch Classification Definitions
Class Max. Trailer Hitch Industry Standards
Class I - Light Duty 2,000 lbs (907 kg)
Class II - Medium Duty 3,500 lbs (1,587 kg)
Class III - Heavy Duty 6,000 lbs (2,722 kg)
Class IV - Extra Heavy Duty 10,000 lbs (4,535 kg)
Fifth Wheel/Gooseneck Greater than 10,000 lbs (4,535 kg)
Refer to the “Trailer Towing Weights (Maximum Trailer Weight Ratings)” for the Maximum Gross Trailer Weight (GTW) towable for your given drivetrain.
All trailer hitches should be professionally installed on your vehicle.

21_DPF_OM_EN_USC_t.book Page 204

STARTING AND OPERATING205
TRAILER TOWING WEIGHTS (MAXIMUM
T
RAILER WEIGHT RATINGS)
NOTE:
For trailer towing information (maximum trailer
weight ratings) refer to the following website
addresses:
ramtrucks.com/en/towing_guide/
ramtruck.ca (Canada)
rambodybuilder.com
TRAILER AND TONGUE WEIGHT
Never exceed the maximum tongue weight
stamped on your bumper or trailer hitch.

Weight Distribution
Consider the following items when computing
the weight on the rear axle of the vehicle:The tongue weight of the trailer.
The weight of any other type of cargo or
equipment put in or on your vehicle.
The weight of the driver and all passengers.
NOTE:

Remember that everything put into or on the
trailer adds to the load on your vehicle. Also, addi -
tional factory-installed options or dealer-installed
options must be considered as part of the total
load on your vehicle. For the maximum combined
weight of occupants and cargo for your vehicle

Ú
page 411.

TOWING REQUIREMENTS
To promote proper break-in of your new vehicle
drivetrain components, the following guidelines
are recommended.
Perform the maintenance listed in the
“Scheduled Servicing” Ú page 353. When
towing a trailer, never exceed the GAWR or
GCWR ratings.
CAUTION!
Always load a trailer with 60% of the weight in
the front of the trailer. This places 10% of the
GTW on the tow hitch of your vehicle. Loads
balanced over the wheels or heavier in the
rear can cause the trailer to sway severely
side to side which will cause loss of control of
the vehicle and trailer. Failure to load trailers
heavier in front is the cause of many trailer
collisions.
CAUTION!
Do not tow a trailer at all during the first
500 miles (805 km) the new vehicle is driven. The engine, axle or other parts could
be damaged.
Then, during the first 500 miles (805 km)
that a trailer is towed, do not drive over
50 mph (80 km/h) and do not make starts
at full throttle. This helps the engine and
other parts of the vehicle wear in at the
heavier loads.
4

21_DPF_OM_EN_USC_t.book Page 205

206STARTING 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.
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.
For the proper tire replacement procedures.
Replacing tires with a higher load carrying
capacity will not increase the vehicle's GVWR
and GAWR limits.
For further information Ú page 406.
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).
WARNING!

Make certain that the load is secured in the
trailer and will not shift during travel. When
trailering cargo that is not fully secured,
dynamic load shifts can occur that may be diffi -
cult for the driver to control. You could lose
control of your vehicle and have a collision.

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.
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)

21_DPF_OM_EN_USC_t.book Page 206

STARTING AND OPERATING207
Integrated Trailer Brake Module — If
Equipped
Your vehicle may have an Integrated Trailer
Brake Module (ITBM) for Electric and Electric
Over Hydraulic (EOH) trailer brakes.
NOTE:
This module has been designed and verified
with electric trailer brakes and new EOH
systems. Some previous EOH systems may not
be compatible with ITBM.

Integrated Trailer Brake Module (ITBM)
The user interface consists of the following:
Manual Brake Control Lever
Slide the manual brake control lever to the left
to activate power to the trailer's electric brakes
independent of the tow vehicle's brakes. If the
manual brake control lever is activated while
the brake is also applied, the greater of the two
inputs determines the power sent to the trailer
brakes.
The trailer and the vehicle’s stop lamps will
come on when braking normally with the vehicle
brake pedal. Only the trailer stop lamps will
come on when the manual brake control lever is
applied.
Trailer Brake Status Indicator Light
This light indicates the trailer electrical
connection status.

If no electrical connection is detected after the
ignition is turned on, pushing the GAIN adjustment
button or sliding the manual brake control lever will
display the GAIN setting for 10 seconds and the
“Trailer Brake Status Indicator Light” will not be
displayed.

WARNING!
Do not connect trailer brakes to your
vehicle's hydraulic brake lines. It can over
-
load your brake system and cause it to fail.
You might not have brakes when you need
them and could have an accident.
Towing any trailer will increase your stop -
ping distance. When towing, you should
allow for additional space between your
vehicle and the vehicle in front of you.
Failure to do so could result in an accident.
CAUTION!
If the trailer weighs more than 1,000 lbs
(453 kg) loaded, it should have its own
brakes and they should be of adequate
capacity. Failure to do this could lead to
accelerated brake lining wear, higher brake
pedal effort, and longer stopping distances.
1 — GAIN - Adjustment Button
2 — GAIN + Adjustment Button
3 — Manual Brake Control Lever
4

21_DPF_OM_EN_USC_t.book Page 207

208STARTING AND OPERATING
If a fault is detected in the trailer wiring or the
Integrated Trailer Brake Module (ITBM), the
“Trailer Brake Status Indicator Light” will flash.
GAIN Adjustment Buttons (+/-)
Pushing these buttons will adjust the brake
control power output to the trailer brakes in
0.5 increments. The GAIN setting can be
increased to a maximum of 10 or decreased
to a minimum of 0 (no trailer braking).
GAIN
The GAIN setting is used to set the trailer brake
control for the specific towing condition and
should be changed as towing conditions
change. Changes to towing conditions include
trailer load, vehicle load, road conditions and
weather.
Adjusting GAIN
NOTE:
This should only be performed in a traffic-free
environment at speeds of approximately
20–25 mph (30–40 km/h).
1. Make sure the trailer brakes are in good
working condition, functioning normally
and properly adjusted. See a trailer dealer
if necessary.

2. Hook up the trailer and make the electrical connections according to the trailer
manufacturer's instructions.
3. When a trailer with electric/EOH brakes is plugged in, the trailer connected message
should appear in the instrument cluster
display (if the connection is not recognized
by the ITBM, braking functions will not be
available), the GAIN setting will illuminate
and the correct type of trailer must be
selected from the instrument cluster display
options.
4. Push the UP or DOWN button on the steering wheel until “TRAILER TOW”
appears on the screen.
5. Push the RIGHT arrow on the steering wheel to enter “TRAILER TOW”. 6. Push the UP or DOWN buttons until the
Trailer Brake Type appears on the screen.
7. Push the RIGHT arrow and then push the UP or DOWN buttons until the proper Trailer
Brake Type appears on the screen.
8. In a traffic-free environment, tow the trailer on a dry, level surface at a speed of
20–25 mph (30–40 km/h) and squeeze
the manual brake control lever completely.
9. If the trailer wheels lockup (indicated by squealing tires), reduce the GAIN setting; if
the trailer wheels turn freely, increase the
GAIN setting.
Repeat steps 8 and 9 until the GAIN setting is at
a point just below trailer wheel lockup. If towing
a heavier trailer, trailer wheel lockup may not be
attainable even with the maximum GAIN setting
of 10.

21_DPF_OM_EN_USC_t.book Page 208

STARTING AND OPERATING209
* The suggested selection depends and
may change depending on the customer
preferences for braking performance. Condition
of the trailer brakes, driving and road state may
also affect the selection.
Display Messages
The trailer brake control interacts with the
instrument cluster display. Display messages,
along with a single chime, will be displayed
when a malfunction is determined in the trailer
connection, trailer brake control, or on the
trailer Úpage 90. NOTE:
An aftermarket controller may be available
for use with trailers with air or EOH trailer
brake systems. To determine the type of
brakes on your trailer and the availability of
controllers, check with your trailer manufac
-
turer or dealer.
Removal of the ITBM will cause errors and it
may cause damage to the electrical system
and electronic modules of the vehicle. See an
authorized dealer if an aftermarket module is
to be installed.
Towing Requirements — Trailer Lights And
Wiring
Whenever you pull a trailer, regardless of the
trailer size, stoplights and turn signals on the
trailer are required for motoring safety.
The Trailer Tow Package may include a four- and
seven-pin wiring harness. Use a factory
approved trailer harness and connector.
NOTE:
Do not cut or splice wiring into the vehicle’s
wiring harness.
The electrical connections are all complete to
the vehicle but you must mate the harness
to a trailer connector. Refer to the following
illustrations.
Light Electric Heavy Electric Light EOHHeavy EOH
Type of Trailer Brakes Electric Trailer Brakes Electric Trailer Brakes Electric over Hydraulic
Trailer BrakesElectric over Hydraulic
Trailer Brakes
Load
*Under 10,000 lbs (4,536 kg) *Above 10,000 lbs (4,536 kg) *Under 10,000 lbs (4,536 kg) *Above 10,000 lbs (4,536 kg)

WARNING!

Connecting a trailer that is not compatible with
the ITBM system may result in reduced or
complete loss of trailer braking. There may be a
increase in stopping distance or trailer instability
which could result in personal injury.

CAUTION!
Connecting a trailer that is not compatible
with the ITBM system may result in reduced
or complete loss of trailer braking. There may
be a increase in stopping distance or trailer
instability which could result in damage to
your vehicle, trailer, or other property.4

21_DPF_OM_EN_USC_t.book Page 209