wheel RAM CHASSIS CAB 2011 Workshop Manual

with a separate computer to modulate hydraulic pressure
to prevent wheel lockup and help avoid skidding on
slippery surfaces.
The system’s pump motor runs during an ABS stop to
provide regulated hydraulic pressure. The pump motor
makes a low humming noise during operation. This is
normal.
The ABS conducts a low-speed selftest at about 10 mph
(16 km/h). If you have your foot lightly on the brake
while this test is occurring, you may feel slight pedal
movement. The movement can be more apparent on ice
and snow. This is normal.
When you are in a severe braking condition involving
use of the ABS, you will experience some pedal drop as
the vehicle comes to a complete stop. This is the result of
the system reverting to the base brake system and is
normal. Engagement of the ABS may be accompanied by a
pulsing sensation. You may also hear a clicking noise.
These occurrences are normal, and indicate that the
system is functioning.
ABS Warning Light
The ABS includes an amber warning light. When the light
is illuminated, the ABS is not functioning. The system
reverts to standard, non-anti-lock brakes.
WARNING!• Pumping of the anti-lock brakes will diminish
their effectiveness and may lead to an accident.
Pumping makes the stopping distance longer. Just
press firmly on your brake pedal when you need
to slow down or stop.
(Continued)
5 STARTING AND OPERATING 293

When adjusting inflation pressure to a tire and wheel
assembly mounted on a vehicle, use a Remote Mount
Automatic Inflation Kit or see your authorized dealer.
NOTE: Never attempt to re-inflate a tire and wheel
assembly which has been run flat or is extremely under-
inflated without first removing the tire from the wheel
assembly for inspection.
Personnel trained, supervised, and equipped according
to Federal Occupational Safety and Health Administra-
tion (OSHA) should perform this work.
Inflation Pressure Adjustment When Not Mounted to
Vehicle
When adjusting inflation pressure to a tire and wheel
assembly not mounted on a vehicle, use a Remote Mount
Automatic Inflation Kit and a Tire Inflation Cage or see
your authorized dealer. Tire Pressures for High Speed Operation
The manufacturer advocates driving at safe speeds
within posted speed limits. Where speed limits or condi-
tions 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 opera-
tion. Refer to original equipment or an authorized tire
dealer for recommended safe operating speeds, loading
and cold tire inflation pressures.
WARNING!High speed driving with your vehicle under maxi-
mum load is dangerous. The added strain on your
tires could cause them to fail. You could have a
serious accident resulting in serious injury or death.
Don’t drive a vehicle loaded to the maximum capac-
ity at continuous speeds above 75 mph (120 km/h).308 STARTING AND OPERATING

Radial Ply Tires
WARNING!Combining radial ply tires with other types of tires
on your vehicle will cause your vehicle to handle
poorly. The instability could cause an accident result-
ing in serious injury or death. Always use radial ply
tires in sets of four (or six, in case of trucks with dual
rear wheels). Never combine them with other types
of tires.
Cuts and punctures in radial tires are repairable only in
the tread area because of sidewall flexing. Consult your
authorized tire dealer for radial tire repairs. Tire Spinning
When stuck in mud, sand, snow, or ice conditions, do not
spin your vehicle’s wheels faster than 30 mph (48 km/h)
or for longer than 30 seconds continuously without
stopping when you are stuck.
Refer to “Freeing A Stuck Vehicle” in “What To Do In
Emergencies” for further information.
WARNING!Fast spinning tires can be dangerous. Forces gener-
ated by excessive wheel speeds may cause tire dam-
age or failure. A tire could explode and injure some-
one. Do not spin your vehicle’s wheels faster than
30 mph (48 km/h) or for more than 30 seconds
continuously when you are stuck, and don’t let
anyone near a spinning wheel, no matter what the
speed.
5 STARTING AND OPERATING 309

WARNING!• Do not use a tire, wheel size or rating other than
that specified for your vehicle. Some combinations
of unapproved tires and wheels may change sus-
pension dimensions and performance characteris-
tics, resulting in changes to steering, handling, and
braking of your vehicle. This can cause unpredict-
able handling and stress to steering and suspen-
sion components. You could lose control and have
an accident resulting in serious injury or death.
Use only the tire and wheel sizes with load ratings
approved for your vehicle.
(Continued) WARNING! (Continued)• 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 an accident result-
ing in serious injury or death.
• Failure to equip your vehicle with tires having
adequate speed capability can result in sudden tire
failure and loss of vehicle control resulting in
serious injury or death.
CAUTION!Replacing original tires with tires of a different size
may result in false speedometer and odometer read-
ings.312 STARTING AND OPERATING

SUPPLEMENTAL TIRE PRESSURE
INFORMATION — IF EQUIPPED
A light load vehicle condition is defined as two passen-
gers [150 lbs (68 kg) each] plus 200 lbs (91 kg) of cargo.
Cold tire inflation pressures for a lightly loaded vehicle
will be found on the face of the driver’s door.
TIRE CHAINS
Use “Class U” chains or other traction aids that meet SAE
Type “U” specifications.
NOTE: Chains must be the proper size for the vehicle,
as recommended by the chain manufacturer.
CAUTION!To avoid damage to your vehicle, tires or chains,
observe the following precautions:
(Continued) CAUTION! (Continued)• Because of limited chain clearance between tires
and other suspension components, it is important
that only chains in good condition are used. Bro-
ken chains can cause serious vehicle damage. Stop
the vehicle immediately if noise occurs that could
suggest chain breakage. Remove the damaged
parts of the chain before further use.
• Install chains as tightly as possible and then
retighten after driving about 1/2 mi (0.8 km).
• Do not exceed 45 mph (72 km/h).
• Drive cautiously and avoid severe turns and large
bumps, especially with a loaded vehicle.
• Do not install tire chains on front wheels of 4x2
vehicles.
• Do not drive for a prolonged period on dry pave-
ment.
(Continued)5 STARTING AND OPERATING 313

CAUTION! (Continued)• Observe the tire chain manufacturer’s instructions
on method of installation, operating speed, and
conditions for usage. Always use the lower sug-
gested operating speed of the chain manufacturer
if different than the speed recommended by the
manufacturer.
These cautions apply to all chain traction devices, includ-
ing link and cable (radial) chains.
Tire chain use is permitted only on the rear tires of your
4X2 trucks.
NOTE:
• The use of class “U” chains is permitted on the front
and rear of 4X4 vehicles, trucks with dual rear wheels
and LT235/80R17E tires. • On 4X2 vehicles, class “U” snow chains are permitted
on the rear wheels only of vehicles equipped with
LT245/70R17, LT265/70R17, and LT235/80R17 size
tires.
• On 4X4 Single Rear Wheel (SRW) vehicles, class “U”
snow chains are permitted on the rear wheels only on
vehicles equipped with LT265/70R17.
CAUTION!Do not use tire chains on the 4X2 front wheels of
SRW (Single Rear Wheels) equipped with LT245/
70R17, LT265/70R17 tires or 4X4 front tires of vehicles
equipped with LT265/70R17tires. There may not be
adequate clearance for the chains and you are risking
structural or body damage to your vehicle.314 STARTING AND OPERATING

Refer to “Maintenance Schedule” for the proper mainte-
nance intervals. More frequent rotation is permissible if
desired. The reasons for any rapid or unusual wear
should be corrected prior to rotation being performed.
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 recommended intervals.
Dual Rear Wheels
The tires used on dual wheel assemblies should be
matched for wear to prevent overloading one tire in a set.Tire Rotation
Tire Rotation316 STARTING AND OPERATING

To check if tires are even, lay a straight edge across all
four tires. The straight edge should touch all the tires.
CAUTION!4500/5500 Dual Rear Tires have only one approved
direction of rotation. This is to accommodate the
asymmetrical 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 re-
mounted on the rim so that the wheel is dished
inward. That way the tread design of asymmetrical
tires will maintain proper position. FUEL REQUIREMENTS
The 5.7L engine is designed to meet all
emissions regulations and provide satisfac-
tory fuel economy and performance when
using high-quality unleaded gasoline hav-
ing an octane range of 87 to 89. The manu-
facturer recommends the use of 89 octane
for optimum performance. The use of premium gasoline
is not recommended, as it will not provide any benefit
over regular gasoline in these engines.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required.
Poor quality gasoline can cause problems such as hard
starting, stalling and hesitations. If you experience these
symptoms, try another brand of “regular” gasoline be-
fore considering service for the vehicle.
5 STARTING AND OPERATING 317

VEHICLE LOADING
Certification Label
As required by National Highway Traffic Safety Admin-
istration regulations, your vehicle has a certification label
affixed to the driver’s side door or pillar.
This label contains the month and year of manufacture,
Gross Vehicle Weight Rating (GVWR), Gross Axle Weight
Rating (GAWR) front and rear, and Vehicle Identification
Number (VIN). A Month-Day-Hour (MDH) number is
included on this label and indicates the Month, Day and
Hour of manufacture. The bar code that appears on the
bottom of the label is your Vehicle Identification Number
(VIN).
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total permissible weight of your vehicle
including driver, passengers, vehicle, options and cargo.
The label also specifies maximum capacities of front and rear axle systems (GAWR). Total load must be limited so
GVWR and front and rear GAWR are not exceeded.
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.324 STARTING AND OPERATING

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.
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 Classification
Your vehicle may be factory equipped for safe towing of
trailers weighing over 5,000 lbs (2 268 kg) with the
optional Trailer Tow Prep Package. See your authorized
dealer for package content.
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.
Refer to “Trailer Towing Weights (Maximum Trailer
Weight Ratings)” for the website address that contains
the necessary information for your specific drivetrain.
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 (1587 kg)
Class III - Heavy Duty 5,000 lbs (2268 kg)
Class IV - Extra
Heavy Duty 10,000 lbs (4540 kg)
Fifth Wheel/
Gooseneck Greater than 10,000 lbs
(4540 kg)
Refer to the “Trailer Towing Weights (Maximum
Trailer Weight Ratings)” for the Maximum Gross
Trailer Weight (GTW) towable for your given drive-
train. 5 STARTING AND OPERATING 329