wheel size RAM CHASSIS CAB 2021 User Guide

SAFETY285
NOTE:
The TPMS is not intended to replace normal
tire care and maintenance or to provide
warning of a tire failure or condition.
If your vehicle is not equipped with the Tire
Fill Alert feature the TPMS should not be used
as a tire pressure gauge while adjusting your
tire pressure.
Driving on a significantly underinflated tire
causes the tire to overheat and can lead to
tire failure. Underinflation also reduces fuel
efficiency and tire tread life, and may affect
the vehicle’s handling and stopping ability.

The TPMS is not a substitute for proper tire
maintenance, and it is the driver’s responsi -
bility to maintain correct tire pressure using an
accurate tire pressure gauge, even if underin-
flation has not reached the level to trigger illu -
mination of the TPMS Warning Light.

Seasonal temperature changes will affect
tire pressure, and the TPMS will monitor the
actual tire pressure in the tire.
Example: Tire Pressure Monitoring System Display

The Tire Pressure Monitoring System (TPMS)
uses wireless technology with wheel rim
mounted electronic sensors to monitor tire
pressure levels. Sensors, mounted to each
wheel as part of the valve stem, transmit tire
pressure readings to the receiver module.
NOTE:
It is particularly important for you to check the
tire pressure in all of the tires on your vehicle
monthly and to maintain the proper pressure.
CAUTION!
The TPMS has been optimized for the orig -
inal equipment tires and wheels. TPMS
pressures and warning have been estab -
lished for the tire size equipped on your
vehicle. Undesirable system operation or
sensor damage may result when using
replacement equipment that is not of the
same size, type, and/or style. Aftermarket
wheels can cause sensor damage.
Using aftermarket tire sealants may cause
the Tire Pressure Monitoring System
(TPMS) sensor to become inoperable.
After using an aftermarket tire sealant it is
recommended that you take your vehicle to
an authorized dealership to have your
sensor function checked.
After inspecting or adjusting the tire pres -
sure always reinstall the valve stem cap.
This will prevent moisture and dirt from
entering the valve stem, which could
damage the TPMS sensor.
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SAFETY287

value will display in place of the dashes. A system
fault can occur due to any of the following:

Signal interference due to electronic devices
or driving next to facilities emitting the same
radio frequencies as the TPMS sensors.
Installing aftermarket window tinting that
contains materials that may block radio wave
signals.
Accumulation of snow or ice around the
wheels or wheel housings.
Using tire chains on the vehicle.
Using wheels/tires not equipped with TPMS
sensors.

A system fault may occur due to an incorrect
TPMS sensor location condition. When a system
fault occurs due to an incorrect TPMS sensor
location, the Tire Pressure Monitoring System
Warning Light will flash on and off for 75 seconds
and then remain on solid. The system fault will
also sound a chime. In addition, the instrument
cluster will display a “Tire Pressure Temporarily
Unavailable” message in place of the tire
pressure display screen. If the ignition switch is
cycled, this sequence will repeat, providing the
system fault still exists. If the system fault no longer exists, the Tire Pressure Monitoring
System Indicator Light will no longer flash and the
tire pressure display screen will be displayed
showing the tire pressure values in the correct
locations.

Vehicles With Non-Matching Full Size Spare Or
Compact Spare
The non-matching full size spare or compact
spare tire does not have a TPMS sensor.
Therefore, the TPMS will not monitor the
pressure in the non-matching full size spare
or compact spare tire.
If you install the non-matching full size spare
or compact spare tire in place of a road tire
that has a pressure below the low-pressure
warning limit, upon the next ignition switch
cycle, the TPMS Warning Light and a “LOW
TIRE” message will remain on and a chime
will sound. In addition, the graphic in the
instrument cluster will still display a pressure
value in a different color and an “Inflate to
XX” message.
After driving the vehicle for up to 20 minutes
above 15 mph (24 km/h), the TPMS Warning
Light will flash on and off for 75 seconds and
then remain on solid. In addition, the instru -ment cluster will display a "SERVICE TPM
SYSTEM" message for a minimum of
five seconds and then display dashes (- -) in
place of the pressure value.

For each subsequent ignition switch cycle, a
chime will sound, the TPMS Warning Light will
flash on and off for 75 seconds and then
remain on solid, and the instrument cluster will
display a "SERVICE TPM SYSTEM" message for
a minimum of five seconds and then display
dashes (- -) in place of the pressure value.

Once you repair or replace the original road
tire and reinstall it on the vehicle in place of
the non matching full size spare or compact
spare, the TPMS will update automatically.
In addition, the TPMS Warning Light will turn
off and the graphic in the instrument cluster
will display a new pressure value instead of
dashes (- -), as long as no tire pressure is
below the low-pressure warning limit in any of
the four active road tires. The vehicle may
need to be driven for up to 20 minutes above
15 mph (24 km/h) in order for the TPMS to
receive this information.
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SAFETY305
Front Air Bag Operation

Front Air Bags are designed to provide additional
protection by supplementing the seat belts. Front
air bags are not expected to reduce the risk of
injury in rear, side, or rollover collisions. The front
air bags will not deploy in all frontal collisions,
including some that may produce substantial
vehicle damage — for example, some pole
collisions, truck underrides, and angle offset
collisions.

On the other hand, depending on the type and
location of impact, front air bags may deploy in
crashes with little vehicle front-end damage but
that produce a severe initial deceleration.
Because air bag sensors measure vehicle
deceleration over time, vehicle speed and
damage by themselves are not good indicators
of whether or not an air bag should have
deployed.
Seat belts are necessary for your protection in
all collisions, and also are needed to help keep
you in position, away from an inflating air bag.
When the Occupant Restraint Controller (ORC)
detects a collision requiring the front air bags, it
signals the inflator units. A large quantity of
non-toxic gas is generated to inflate the front air
bags.

The steering wheel hub trim cover and the
upper passenger side of the instrument panel
separate and fold out of the way as the air bags
inflate to their full size. The front air bags fully
inflate in less time than it takes to blink your
eyes. The front air bags then quickly deflate
while helping to restrain the driver and front
passenger.
Knee Impact Bolsters
The Knee Impact Bolsters help protect the
knees of the driver and front passenger, and
position the front occupants for improved
interaction with the front air bags.
WARNING!
No objects should be placed over or near
the air bag on the instrument panel or
steering wheel because any such objects
could cause harm if the vehicle is in a colli
-
sion severe enough to cause the air bag to
inflate.

Do not put anything on or around the air bag
covers or attempt to open them manually.
You may damage the air bags and you could
be injured because the air bags may no
longer be functional. The protective covers
for the air bag cushions are designed to open
only when the air bags are inflating.

Relying on the air bags alone could lead to
more severe injuries in a collision. The air
bags work with your seat belt to restrain you
properly. In some collisions, air bags won’t
deploy at all. Always wear your seat belts
even though you have air bags.
WARNING!
Do not drill, cut, or tamper with the knee
impact bolsters in any way.
Do not mount any accessories to the knee
impact bolsters such as alarm lights,
stereos, citizen band radios, etc.
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SERVICING AND MAINTENANCE403
4. Reach through the access hole of the wheel
house splash shield and disengage the bulb
access cover by rotating counterclockwise.

Bulb Access Cover

5. Disconnect the internal lamp wiring harness connector from the low beam bulb. 6. Rotate the bulb counterclockwise a quarter
turn to unlock the bulb from the lamp.
7. Pull the bulb straight out from the housing.
8. Reverse the procedure for installation of new bulb and covers.
High Beam
See below steps to replace:

1. Open the hood.

2. Disconnect and isolate the negative battery cable.

Bulb Access Cover

3. Look under the hood and behind the headlamp to find the high beam bulb
access cover. 4. Reach behind the headlamp and disengage
the access cover by rotating counter -
clockwise.
5. Disconnect the internal lamp wiring harness connector from the high beam bulb.
6. Rotate the bulb counterclockwise a quarter turn to unlock the bulb from the lamp.
7. Pull the bulb straight out from the housing.
8. Reverse the procedure for installation of new bulb and covers.
CAUTION!
Do not contaminate the bulb glass by
touching it with your fingers or by allowing it
to contact other oily surfaces. Shortened
bulb life will result.

Always use the correct bulb size and type for
replacement. An incorrect bulb size or type
may overheat and cause damage to the
lamp, the bulb socket, or the lamp wiring.

CAUTION!
Do not contaminate the bulb glass by
touching it with your fingers or by allowing it
to contact other oily surfaces. Shortened
bulb life will result.
Always use the correct bulb size and type
for replacement. An incorrect bulb size or
type may overheat and cause damage to
the lamp, the bulb socket, or the lamp
wiring.
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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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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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