2021 RAM CHASSIS CAB Owners Manual

SERVICING AND MAINTENANCE415
Tire Inflation Pressures
The proper cold tire inflation pressure is listed
on the driver's side B-pillar or rear edge of the
driver's side door.
At least once a month:
Check and adjust tire pressure with a good
quality pocket-type pressure gauge. Do not
make a visual judgment when determining
proper inflation. Tires may look properly
inflated even when they are underinflated.
Inspect tires for signs of tire wear or visible
damage.
Inflation pressures specified on the placard are
always “cold tire inflation pressure”. Cold tire
inflation pressure is defined as the tire pressure
after the vehicle has not been driven for at least
three hours, or driven less than 1 mile (1.6 km) after sitting for a minimum of three hours. The
cold tire inflation pressure must not exceed the
maximum inflation pressure molded into the
tire sidewall.
Check tire pressures more often if subject to a
wide range of outdoor temperatures, as tire
pressures vary with temperature changes.
Tire pressures change by approximately 1 psi
(7 kPa) per 12°F (7°C) of air temperature
change. Keep this in mind when checking tire
pressure inside a garage, especially in the
Winter.
Example: If garage temperature = 68°F (20°C)
and the outside temperature = 32°F (0°C) then
the cold tire inflation pressure should be
increased by 3 psi (21 kPa), which equals 1 psi
(7 kPa) for every 12°F (7°C) for this outside
temperature condition.
Tire pressure may increase from 2 to 6 psi
(13 to 40 kPa) during operation. DO NOT reduce
this normal pressure build up or your tire
pressure will be too low.
Tire Pressures For High Speed Operation

The manufacturer advocates driving at safe
speeds and within posted speed limits. Where
speed limits or conditions are such that the
vehicle can be driven at high speeds, maintaining
correct tire inflation pressure is very important.
Increased tire pressure and reduced vehicle
loading may be required for high-speed vehicle
operation. Refer to an authorized tire dealer
or original equipment vehicle dealer for
recommended safe operating speeds, loading
and cold tire inflation pressures.

CAUTION!

After inspecting or adjusting the tire pressure,
always reinstall the valve stem cap. This will
prevent moisture and dirt from entering the valve
stem, which could damage the valve stem.

WARNING!

High speed driving with your vehicle under
maximum load is dangerous. The added strain
on your tires could cause them to fail. You
could have a serious collision. Do not drive a
vehicle loaded to the maximum capacity at
continuous speeds above 75 mph (120 km/h).

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416SERVICING AND MAINTENANCE
Radial Ply Tires
Tire Repair
If your tire becomes damaged, it may be
repaired if it meets the following criteria:
The tire has not been driven on when flat.
The damage is only on the tread section of
your tire (sidewall damage is not repairable).
The puncture is no greater than a ¼ of an
inch (6 mm).
Consult an authorized tire dealer for tire repairs
and additional information.

Damaged Run Flat tires, or Run Flat tires that have
experienced a loss of pressure should be replaced
immediately with another Run Flat tire of identical
size and service description (Load Index and Speed
Symbol). Replace the tire pressure sensor as well as
it is not designed to be reused.

Run Flat Tires — If Equipped
Run Flat tires allow you the capability to drive
50 miles (80 km) at 50 mph (80 km/h) after a
rapid loss of inflation pressure. This rapid loss
of inflation is referred to as the Run Flat mode.
A Run Flat mode occurs when the tire inflation
pressure is of/or below 14 psi (96 kPa). Once a
Run Flat tire reaches the Run Flat mode it has
limited driving capabilities and needs to be
replaced immediately. A Run Flat tire is not
repairable. When a Run Flat tire is changed
after driving with underinflated tire condition,
please replace the TPM sensor as it is not
designed to be reused when driven under Run
Flat mode 14 psi (96 kPa) condition.
NOTE:
TPM Sensor must be replaced after driving the
vehicle on a flat tire condition.
It is not recommended driving a vehicle loaded
at full capacity or to tow a trailer while a tire is in
the Run Flat mode.
See the tire pressure monitoring section for
more information.
Tire Spinning
When stuck in mud, sand, snow, or ice
conditions, do not spin your vehicle's wheels
above 30 mph (48 km/h) or for longer than
30 seconds continuously without stopping.WARNING!

Combining radial ply tires with other types of tires
on your vehicle will cause your vehicle to handle
poorly. The instability could cause a collision.
Always use radial ply tires in sets of four. Never
combine them with other types of tires.

WARNING!

Fast spinning tires can be dangerous. Forces
generated by excessive wheel speeds may
cause tire damage or failure. A tire could
explode and injure someone. Do not spin your
vehicle's wheels faster than 30 mph (48 km/h)
for more than 30 seconds continuously when
you are stuck, and do not let anyone near a
spinning wheel, no matter what the speed.

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SERVICING AND MAINTENANCE417
Tread Wear Indicators
Tread wear indicators are in the original
equipment tires to help you in determining
when your tires should be replaced.

Tire Tread

These indicators are molded into the bottom of
the tread grooves. They will appear as bands
when the tread depth becomes a 1/16 of an
inch (1.6 mm). When the tread is worn to the
tread wear indicators, the tire should be
replaced.
Life Of Tire
The service life of a tire is dependent upon
varying factors including, but not limited to:
Driving style.

Tire pressure - Improper cold tire inflation pres -
sures can cause uneven wear patterns to
develop across the tire tread. These abnormal
wear patterns will reduce tread life, resulting in
the need for earlier tire replacement.

Distance driven.
Performance tires, tires with a speed rating of
V or higher, and Summer tires typically have
a reduced tread life. Rotation of these tires
per the vehicle scheduled maintenance is
highly recommended. NOTE:
Wheel valve stem must be replaced as well
when installing new tires due to wear and tear
in existing tires.
Keep dismounted tires in a cool, dry place with
as little exposure to light as possible. Protect
tires from contact with oil, grease, and gasoline.
Replacement Tires

The tires on your new vehicle provide a balance of
many characteristics. They should be inspected
regularly for wear and correct cold tire inflation
pressures. The manufacturer strongly recommends
that you use tires equivalent to the originals in size,
quality and performance when replacement is
needed

Ú
page 417. Refer to the Tire and Loading
Information placard or the Vehicle Certification
Label for the size designation of your tire. The Load
Index and Speed Symbol for your tire will be found
on the original equipment tire sidewall.

For more information relating to the Load Index
and Speed Symbol of a tire Ú page 406.
It is recommended to replace the two front tires
or two rear tires as a pair. Replacing just one tire
can seriously affect your vehicle’s handling.
1 — Worn Tire
2 — New Tire
WARNING!
Tires and the spare tire should be replaced
after six years, regardless of the remaining
tread. Failure to follow this warning can result
in sudden tire failure. You could lose control
and have a collision resulting in serious injury
or death.
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418SERVICING AND MAINTENANCE
(Continued)
If you ever replace a wheel, make sure that the
wheel’s specifications match those of the
original wheels.
It is recommended you contact an authorized
tire dealer or original equipment dealer with any
questions you may have on tire specifications
or capability. Failure to use equivalent
replacement tires may adversely affect the
safety, handling, and ride of your vehicle.TIRE TYPES
All Season Tires — If Equipped
All Season tires provide traction for all seasons
(Spring, Summer, Autumn, and Winter). Traction
levels may vary between different all season
tires. All season tires can be identified by the
M+S, M&S, M/S or MS designation on the tire
sidewall. Use all season tires only in sets of four;
failure to do so may adversely affect the safety
and handling of your vehicle.
Summer Or Three Season Tires — If
Equipped
Summer tires provide traction in both wet and
dry conditions, and are not intended to be
driven in snow or on ice. If your vehicle is
equipped with Summer tires, be aware these
tires are not designed for Winter or cold driving
conditions. Install Winter tires on your vehicle
when ambient temperatures are less than 40°F
(5°C) or if roads are covered with ice or snow.
For more information, contact an authorized
dealer.
WARNING!
Do not use a tire, wheel size, load rating, or
speed rating other than that specified for
your vehicle. Some combinations of unap -
proved tires and wheels may change
suspension dimensions and performance
characteristics, resulting in changes to
steering, handling, and braking of your
vehicle. This can cause unpredictable
handling and stress to steering and
suspension components. You could lose
control and have a collision resulting in
serious injury or death. Use only the tire and
wheel sizes with load ratings approved for
your vehicle.
Never use a tire with a smaller load index or
capacity, other than what was originally
equipped on your vehicle. Using a tire with
a smaller load index could result in tire
overloading and failure. You could lose
control and have a collision.
Failure to equip your vehicle with tires
having adequate speed capability can
result in sudden tire failure and loss of
vehicle control.
CAUTION!
Replacing original tires with tires of a
different size may result in false speedometer
and odometer readings.
WARNING! (Continued)

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SERVICING AND MAINTENANCE419
Summer tires do not contain the all season
designation or mountain/snowflake symbol on
the tire sidewall. Use Summer tires only in sets
of four; failure to do so may adversely affect the
safety and handling of your vehicle.
Snow Tires
Some areas of the country require the use of
snow tires during the Winter. Snow tires can be
identified by a “mountain/snowflake” symbol
on the tire sidewall.
If you need snow tires, select tires
equivalent in size and type to the
original equipment tires. Use snow
tires only in sets of four; failure to do
so may adversely affect the safety and handling
of your vehicle. Snow tires generally have lower speed ratings
than what was originally equipped with your
vehicle and should not be operated at
sustained speeds over 75 mph (120 km/h).
For speeds above 75 mph (120 km/h) refer to
original equipment or an authorized tire dealer
for recommended safe operating speeds,
loading and cold tire inflation pressures.
While studded tires improve performance
on ice, skid and traction capability on wet or
dry surfaces may be poorer than that of
non-studded tires. Some states prohibit
studded tires; therefore, local laws should
be checked before using these tire types.SPARE TIRES — IF EQUIPPED
For restrictions when towing with a spare tire
designated for temporary emergency use
Ú
page 206.
Spare Tire Matching Original Equipped Tire
And Wheel — If Equipped
Your vehicle may be equipped with a spare tire
and wheel equivalent in look and function to the
original equipment tire and wheel found on the
front or rear axle of your vehicle. This spare tire
may be used in the tire rotation for your vehicle.
If your vehicle has this option, refer to an
authorized tire dealer for the recommended tire
rotation pattern.
Compact Spare Tire — If Equipped
The compact spare is for temporary emergency
use only. You can identify if your vehicle is
equipped with a compact spare by looking at
the spare tire description on the Tire and
Loading Information Placard located on the
driver’s side door opening or on the sidewall of
the tire. Compact spare tire descriptions begin
with the letter “T” or “S” preceding the size
designation. Example: T145/80D18 103M.
T, S = Temporary Spare Tire
Since this tire has limited tread life, the original
equipment tire should be repaired (or replaced)
and reinstalled on your vehicle at the first
opportunity.
WARNING!
Do not use Summer tires in snow/ice
conditions. You could lose vehicle control,
resulting in severe injury or death. Driving too
fast for conditions also creates the possibility
of loss of vehicle control.
CAUTION!
Because of the reduced ground clearance, do
not take your vehicle through an automatic
car wash with a compact or limited use
temporary spare installed. Damage to the
vehicle may result.8

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420SERVICING AND MAINTENANCE
Do not install a wheel cover or attempt to mount
a conventional tire on the compact spare wheel,
since the wheel is designed specifically for the
compact spare tire. Do not install more than
one compact spare tire and wheel on the
vehicle at any given time.Collapsible Spare Tire — If Equipped
The collapsible spare is for temporary
emergency use only. You can identify if your
vehicle is equipped with a collapsible spare by
looking at the spare tire description on the Tire
and Loading Information Placard located on the
driver’s side door opening or on the sidewall of
the tire.
Collapsible spare tire description example:
165/80-17 101P.
Since this tire has limited tread life, the original
equipment tire should be repaired (or replaced)
and reinstalled on your vehicle at the first
opportunity.
Inflate collapsible tire only after the wheel is
properly installed to the vehicle. Inflate the
collapsible tire using the electric air pump
before lowering the vehicle.
Do not install a wheel cover or attempt to mount
a conventional tire on the collapsible spare
wheel, since the wheel is designed specifically
for the collapsible spare tire.
Full Size Spare — If Equipped
The full size spare is for temporary emergency
use only. This tire may look like the originally
equipped tire on the front or rear axle of your
vehicle, but it is not. This spare tire may have
limited tread life. When the tread is worn to the
tread wear indicators, the temporary use full
size spare tire needs to be replaced. Since it is
not the same as your original equipment tire,
replace (or repair) the original equipment tire
and reinstall on the vehicle at the first
opportunity.
WARNING!
Compact and collapsible spares are for
temporary emergency use only. With these
spares, do not drive more than 50 mph
(80 km/h). Temporary use spares have
limited tread life. When the tread is worn to
the tread wear indicators, the temporary use
spare tire needs to be replaced. Be sure to
follow the warnings, which apply to your
spare. Failure to do so could result in spare
tire failure and loss of vehicle control.
WARNING!
Compact and Collapsible spares are for
temporary emergency use only. With these
spares, do not drive more than 50 mph
(80 km/h). Temporary use spares have
limited tread life. When the tread is worn to
the tread wear indicators, the temporary use
spare tire needs to be replaced. Be sure to
follow the warnings, which apply to your
spare. Failure to do so could result in spare
tire failure and loss of vehicle control.

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SERVICING AND MAINTENANCE421
Limited Use Spare — If Equipped
The limited use spare tire is for temporary
emergency use only. This tire is identified by a
label located on the limited use spare wheel.
This label contains the driving limitations for
this spare. This tire may look like the original
equipped tire on the front or rear axle of your
vehicle, but it is not. Installation of this limited
use spare tire affects vehicle handling. Since it
is not the same as your original equipment tire,
replace (or repair) the original equipment tire
and reinstall on the vehicle at the first
opportunity.
WHEEL AND WHEEL TRIM CARE
All wheels and wheel trim, especially aluminum
and chrome plated wheels, should be cleaned
regularly using mild (neutral Ph) soap and water
to maintain their luster and to prevent
corrosion. Wash wheels with the same soap
solution recommended for the body of the
vehicle and remember to always wash when the
surfaces are not hot to the touch.
Your wheels are susceptible to deterioration
caused by salt, sodium chloride, magnesium
chloride, calcium chloride, etc., and other road
chemicals used to melt ice or control dust on
dirt roads. Use a soft cloth or sponge and mild
soap to wipe away promptly. Do not use harsh
chemicals or a stiff brush. They can damage the
wheel’s protective coating that helps keep them
from corroding and tarnishing.
When cleaning extremely dirty wheels including
excessive brake dust, care must be taken in the
selection of tire and wheel cleaning chemicals
and equipment to prevent damage to the wheels.
Mopar Wheel Treatment or Mopar Chrome
Cleaner or their equivalent is recommended or
select a non-abrasive, non-acidic cleaner for
aluminum or chrome wheels.

WARNING!
Limited use spares are for emergency use
only. Installation of this limited use spare tire
affects vehicle handling. With this tire, do not
drive more than the speed listed on the
limited use spare wheel. Keep inflated to the
cold tire inflation pressures listed on your Tire
and Loading Information Placard located on
the driver’s side B-pillar or the rear edge of
the driver’s side door. Replace (or repair) the
original equipment tire at the first opportunity
and reinstall it on your vehicle. Failure to do
so could result in loss of vehicle control.
CAUTION!

Avoid products or automatic car washes that
use acidic solutions or strong alkaline additives
or harsh brushes. Many aftermarket wheel
cleaners and automatic car washes may
damage the wheel's protective finish. Such
damage is not covered by the New Vehicle
Limited Warranty. Only car wash soap, Mopar
Wheel Cleaner or equivalent is recommended.

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422SERVICING AND MAINTENANCE
NOTE:
If you intend parking or storing your vehicle for
an extended period after cleaning the wheels
with wheel cleaner, drive your vehicle and apply
the brakes to remove the water droplets from the brake components. This activity will remove
the red rust on the brake rotors and prevent
vehicle vibration when braking.
Dark Vapor Chrome, Black Satin Chrome, or
Low Gloss Clear Coat Wheels
SNOW TRACTION DEVICES
Use of traction devices require sufficient
tire-to-body clearance. Due to limited clearance,
the following snow traction devices are
recommended. Follow these recommendations
to guard against damage:
Snow traction device must be of proper size
for the tire, as recommended by the snow
traction device manufacturer.
No other tire sizes are recommended for use
with the snow traction device.
Please follow the table below for the recom
-
mended tire size, axle and snow traction
device:
CAUTION!
Do not use scouring pads, steel wool, a bristle
brush, metal polishes or oven cleaner. These
products may damage the wheel's protective
finish. Such damage is not covered by the
New Vehicle Limited Warranty. Only car wash
soap, Mopar Wheel Cleaner or equivalent is
recommended.
CAUTION!
If your vehicle is equipped with these
specialty wheels, DO NOT USE wheel
cleaners, abrasives, or polishing compounds.
They will permanently damage this finish and
such damage is not covered by the New
Vehicle Limited Warranty. HAND WASH ONLY
USING MILD SOAP AND WATER WITH A SOFT
CLOTH. Used on a regular basis; this is all that
is required to maintain this finish.
3500 SRW CAB CHASSIS
Trim Level Axle
Tire/Wheel Size Snow Traction Device
(maximum projection beyond tire profile or equivalent)
4x2
4x4 Rear
LT275/70R18E U Class

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