tires RAM CHASSIS CAB 2019 Service Manual

SERVICING AND MAINTENANCE 457
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 informa -
tion. 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.
Refer to “Freeing A Stuck Vehicle” in “In Case Of Emer -
gency” for further information.
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.
7

458 SERVICING AND MAINTENANCE
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. Refer to “Replacement Tires” in this section for further infor -
mation.
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 pressures 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. Rota -
tion of these tires per the vehicle scheduled maintenance is
highly recommended.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.

SERVICING AND MAINTENANCE 459
(Continued)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 expo -
sure 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. Refer to the paragraph on “Tread Wear Indica -
tors” in this section. Refer to the Tire and Loading Informa -
tion 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.
See the Tire Sizing Chart example found in the “Tire Safety
Information” section of this manual for more information
relating to the Load Index and Speed Symbol of a tire. 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. If you ever replace a wheel, make
sure that the wheel’s specifications match those of the orig -
inal 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.
WARNING!
• Do not use a tire, wheel size, load rating, or speed rating
other than that specified for your vehicle. Some combi -
nations of unapproved tires and wheels may change
suspension dimensions and performance characteris -
tics, resulting in changes to steering, handling, and
braking of your vehicle. This can cause unpredictable
handling and stress to steering and suspension compo -
nents. 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. 7

460 SERVICING AND MAINTENANCE
Tire Types
All Season Tires — If Equipped
All Season tires provide traction for all seasons (Spring,
Summer, Fall, 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 condi -
tions, 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 tempera -
tures are less than 40°F (5°C) or if roads are covered with ice
or snow. For more information, contact an authorized dealer.
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.• 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)
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.

SERVICING AND MAINTENANCE 461
Snow Tires
Some areas of the country require the use of snow tires
during the Winter. Snow tires can be identified by a “moun -
tain/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
NOTE:
For vehicles equipped with Tire Service Kit instead of a spare
tire, please refer to “Tire Service Kit” in “In Case Of Emer -
gency” for further information.
Refer to the “Towing Requirements - Tires” in “Starting And
Operating” for restrictions when towing with a spare tire
designated for temporary emergency use.
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. 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.
7

466 SERVICING AND MAINTENANCE
(Continued)Tire Rotation Recommendations
Tires on the front and rear axles of vehicles operate at
different loads and perform different steering, driving, and
braking functions. For these reasons, they wear at unequal
rates.
These effects can be reduced by timely rotation of tires. The
benefits of rotation are especially worthwhile with aggres -
sive tread designs such as those on On/Off Road type tires.
Rotation will increase tread life, help to maintain mud, snow,
and wet traction levels, and contribute to a smooth, quiet
ride.WARNING!
Using tires of different size and type (M+S, Snow)
between front and rear axles can cause unpredictable
handling. You could lose control and have a collision.
CAUTION!
To avoid damage to your vehicle or tires, observe the
following precautions:
• Because of restricted traction device clearance between
tires and other suspension components, it is important
that only traction devices in good condition are used.
Broken devices can cause serious damage. Stop the
vehicle immediately if noise occurs that could indicate
device breakage. Remove the damaged parts of the
device before further use.
• Install device as tightly as possible and then retighten
after driving about ½ mile (0.8 km).
• Do not exceed 30 mph (48 km/h).
• Drive cautiously and avoid severe turns and large
bumps, especially with a loaded vehicle.
• Do not drive for a prolonged period on dry pavement. • Observe the traction device manufacturer’s instruc -
tions on the method of installation, operating speed,
and conditions for use. Always use the suggested oper -
ating speed of the device manufacturer’s if it is less
than 30 mph (48 km/h).
• Do not use traction devices on a compact spare tire. CAUTION! (Continued)

SERVICING AND MAINTENANCE 467
Refer to the “Maintenance Plan” for the proper maintenance
intervals. More frequent rotation is permissible if desired.
The reasons for any rapid or unusual wear should be
corrected prior to rotation being performed.
Tire Rotation
NOTE:
On Canadian vehicles only, if your vehicle is equipped with
All-Season type tires on the front and On/Off Road type tires
mounted on the rear, do not use a front to back rotation
pattern. Instead, rotate your tires side to side at the recom -
mended intervals. Dual Rear Wheels
Tire Rotation
The tires used on dual wheel assemblies should be matched
for wear to prevent overloading one tire in a set. To check if
tires are even, lay a straight edge across all four tires. The
straight edge should touch all the tires. 7

468 SERVICING AND MAINTENANCE
(Continued)NOTE:
If your vehicle is equipped with a Tire Pressure Information
System (TPIS):
• The Tire Pressure Information System (TPIS) uses unique
sensors in the inner rear wheels to help identify them from
the outer rear wheels, because of this, the inner and outer
wheel locations can’t be switched.
• After a tire rotation is completed, as shown below, the
system can auto learn the locations of each sensor ID. Auto
learning/localization occurs when the vehicle ignition
status is changed from Off to On and speeds of greater
than 5 mph (8km/h) are obtained and remain over 5mph
(8km/h) for at about a 15 minute period. You may need to
drive for 20 minutes to account slower speeds and stops.
• If the tires are rotated incorrectly, the Auto localization of
the TPIS sensors will fail to locate correctly resulting in
incorrect locations for the pressure values displayed in the
Instrument Cluster. DEPARTMENT OF TRANSPORTATION UNIFORM
TIRE QUALITY GRADES
The following tire grading categories were established by
the National Highway Traffic Safety Administration. The
specific grade rating assigned by the tire's manufacturer
in each category is shown on the sidewall of the tires on
your vehicle.
All passenger vehicle tires must conform to Federal safety
requirements in addition to these grades.CAUTION!
• 4500/5500 Dual Rear Tires may only have one approved
direction of rotation. This is to accommodate the asym -
metrical design (tread pattern) of the On/Off road tire. • When replacing a flat, the spare tire may have to be
remounted on the rim or installed at a different location
to maintain the correct placement of the tire on the
wheel relative to the tire/wheel position on the vehicle.
For example, if the spare is used to replace an outer rear
tire it will have to be remounted on the rim so that the
wheel is dished inward. That way the tread design of
asymmetrical tires will maintain proper position. CAUTION! (Continued)

SERVICING AND MAINTENANCE 469
Treadwear
The Treadwear grade is a comparative rating, based on
the wear rate of the tire when tested under controlled
conditions on a specified government test course. For
example, a tire graded 150 would wear one and one-half
times as well on the government course as a tire graded
100. The relative performance of tires depends upon the
actual conditions of their use, however, and may depart
significantly from the norm due to variations in driving
habits, service practices, and differences in road charac -
teristics and climate.
Traction Grades
The Traction grades, from highest to lowest, are AA, A, B,
and C. These grades represent the tire's ability to stop on
wet pavement, as measured under controlled conditions
on specified government test surfaces of asphalt and
concrete. A tire marked C may have poor traction perfor -
mance. Temperature Grades
The Temperature grades are A (the highest), B, and C,
representing the tire's resistance to the generation of heat
and its ability to dissipate heat, when tested under
controlled conditions on a specified indoor laboratory test
wheel.
Sustained high temperature can cause the material of the
tire to degenerate and reduce tire life, and excessive
temperature can lead to sudden tire failure. The grade C
corresponds to a level of performance, which all
passenger vehicle tires must meet under the Federal
Motor Vehicle Safety Standard No. 109. Grades B and A
represent higher levels of performance on the laboratory
test wheel, than the minimum required by law. WARNING!
The traction grade assigned to this tire is based on
straight-ahead braking traction tests, and does not
include acceleration, cornering, hydroplaning, or peak
traction characteristics.
7

TECHNICAL SPECIFICATIONS 477
Torque Specifications
**Use only your authorized dealer recommended lug nuts/
bolts and clean or remove any dirt or oil before tightening.
Inspect the wheel mounting surface prior to mounting the
tire and remove any corrosion or loose particles.
NOTE:
Dual wheels are flat mounted, center piloted. The lug nuts
are a two-piece assembly. When the tires are being rotated or
replaced, clean these lug nuts and add two drops of oil at the
interface between the hex and the washer. Ensure that the
socket is fully engaged on the lug nut/bolt (do not insert it
half way). Oil Interface Location
Do not oil wheel studs. For chrome wheels, do not substitute
with chrome plated wheel nuts.Lug Nut/Bolt
Torque Lug Nut/Bolt
Type **Lug Nut/
Bolt Size Lug Nut/Bolt
Socket Size
120-150 Ft-Lbs
(160-200 N·m) Cone
M14 x 1.50 22 mm
130-160 Ft-Lbs
(190-220 N·m) Flanged
8