starting and operating Ram 4500 Chassis Cab 2018 Repair Manual

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 in-
creased durability does not necessarily increase the vehi-
cle’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 insure 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 axle. Weighing the
vehicle may show that the GAWR of either the front or rear
axles 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
6
STARTING AND OPERATING 291

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.
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.
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 infor-
mation 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.
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. Refer to “Vehicle Loading/Vehicle Certification
Label” in “Starting And Operating” for further informa-
tion.
Gross Trailer Weight (GTW)
The GTW is the weight of the trailer plus the weight of all
cargo, consumables and equipment (permanent or tempo-
rary) loaded in or on the trailer in itsloaded 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.
292 STARTING AND OPERATING

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.
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.
Refer to “Vehicle Loading/Vehicle Certification Label” in
“Starting And Operating” for further information.
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.
Tongue Weight (TW)
The tongue weight 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
The trailer sway control 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 Trailer Sway Control (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 the
6
STARTING AND OPERATING 293

most popular on the market today and they are commonly
used to tow small and medium sized trailers.
Weight-Distributing Hitch
A weight-distributing 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 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.
WARNING!
•An improperly adjusted weight distributing hitch
system may reduce handling, stability and braking
performance and could result in a collision.
(Continued)
WARNING! (Continued)
•Weight distributing systems may not be compatible
with surge brake couplers. Consult with your hitch
and trailer manufacturer or a reputable Recreational
Vehicle dealer for additional information.
Without Weight-Distributing Hitch (Incorrect)
294 STARTING AND OPERATING

Recommended Distribution Hitch Adjustment
Towing With 1500 Air Suspension
1. Set air suspension to normal ride height. No action isrequired if already in normal ride height.
NOTE: The vehicle must remain in the engine run position
with all doors closed while attaching a trailer for proper
leveling of the air suspension system.
2. Position the truck to be ready to connect to the trailer (do not connect the trailer).
With Weight-Distributing Hitch (Correct)Improper Adjustment Of Weight-Distributing Hitch
(Incorrect)
6
STARTING AND OPERATING 295

3. Under the instrument cluster or touch screen radiosettings, enable jack mode. Jack mode will be canceled
and procedure must be restarted if the vehicle is driven
at speeds above 5mph (8 kmh).
4. Measure the height of the top of the front wheel opening on the fender to ground, this is height H1.
5. Attach the trailer to the vehicle without the weight distribution bars connected.
6. Measure the height of the top of the front wheel opening on the fender to ground, this is height H2. 7. 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)/
3+H1 (about 1/3 the difference between H2 and H1
above normal ride height [H1]).
8. Use the instrument cluster or touch screen radio settings and switch off tire jack mode. Make sure the truck
returns to normal ride height. Preform a visual inspec-
tion of the trailer and weight distributing hitch to
confirm manufacturers’ recommendations have been
met.
9. The truck can now be driven.
Measurement Example Example 1500 Height
(mm)
H1 925
H2 946
H2-H1 21
(H2-H1)/3 7
(H2-H1)/3 + H1 932
NOTE: For all towing conditions, we recommend towing
with tow haul mode engaged.
Measuring Height (H)
296 STARTING AND OPERATING

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.
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. Preform a visual inspection of the trailer and weight
distributing hitch to confirm manufacturers’ recommen-
dations have been met.
Measurement Example Example 2500/3500
Height (mm)
H1 1030
H2 1058
H2-H1 28
(H2-H1)/2 14
(H2-H1)/2 + H1 1044
NOTE: For all towing conditions, we recommend towing
with tow haul mode engaged.
Towing With All Other 1500/2500/3500 (Non-Air Suspen-
sion)
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.
6
STARTING AND OPERATING 297

4. Measure the height of the top of the front wheel openingon 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. Preform a visual inspection of the trailer and weight distributing hitch to confirm manufacturers’ recommen-
dations have been met.
Measurement Example Example 2500/3500
Height (mm)
H1 1030
H2 1058
H2-H1 28
(H2-H1)/2 14
(H2-H1)/2 + H1 1044
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 5th wheel hitch option.
Refer to the separately provided 5th 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.
Trailer Hitch Type and Maximum Trailer Weight
The following chart provides the maximum trailer weight
a given factory equipped trailer hitch type can tow and
should be used to assist you in selecting the correct trailer
hitch for your intended towing condition.
298 STARTING AND OPERATING

Trailer Hitch Type and Maximum Trailer WeightHitch Type Max. Trailer Weight / Max. Tongue Weight
Class III Bumper
Hitch - 1500 Model 5,000 lbs (2,268 kg) / 500 lbs
(226 kg)
Class IV - 1500 Model 11,000 lbs (4,989 kg) / 1100 lbs (498 kg)
Class V - 2500/3500 Models 18,000 lbs (8,164 kg) / 1800
lbs (816 kg)
Fifth Wheel - 2500 Model 25,000 lbs (11,339 kg) / 5000
lbs (2,267 kg)
Gooseneck - 2500 Model 20,000 lbs (9,071 kg) /
4000 lbs (1,814 kg)
Gooseneck Or Fifth
Wheel - 3500 Model 32,000 lbs (14,545 kg) / 6000
lbs (2,721 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.Trailer Towing Weights (Maximum Trailer 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
6
STARTING AND OPERATING 299

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, additional
factory-installed options or dealer-installed options must
be considered as part of the total load on your vehicle.
Refer to the “Tire And Loading Information” placard for
the maximum combined weight of occupants and cargo for
your vehicle.
Towing Requirements
To promote proper break-in of your new vehicle drivetrain
components, the following guidelines are recommended.
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.
(Continued)
CAUTION! (Continued)
•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.
Perform the maintenance listed in the “Scheduled Servic-
ing”. Refer to “Scheduled Servicing” in “Servicing And
Maintenance” for the proper maintenance intervals. When
towing a trailer, never exceed the GAWR or GCWR ratings.
WARNING!
Improper towing can lead to a collision. Follow these
guidelines to make your trailer towing as safe as
possible:
• 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 difficult 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. Overloading can
(Continued)
300 STARTING AND OPERATING