2018 Ram 3500 Chassis Cab tire pressure

4L
Four-Wheel Drive Low Range — This range locks the front
and rear driveshafts together forcing the front and rear
wheels to rotate at the same speed. Additional traction and
maximum pulling power for loose, slippery road surfaces
only. Do not exceed 25 mph (40 km/h).
This transfer case is intended to be driven in the 2H
position for normal street and highway conditions such as
dry, hard surfaced roads.
When additional traction is required, the 4H and 4L
positions can be used to lock the front and rear driveshafts
together and force the front and rear wheels to rotate at the
same speed. This is accomplished by simply moving the
gear selector to the desired positions once the appropriate
speed and gear requirements are met, refer to “Shifting
Procedure – Manually Shifted Transfer Case” in this section
for further information.
The 4H and 4L positions are intended for loose, slippery
road surfaces only. Driving in the 4H and 4L positions on
dry, hard surfaced roads may cause increased tire wear and
damage to the driveline components.
The “Transfer Case Position Indicator Light” in the instru-
ment cluster will alert the driver that the vehicle is infour-wheel drive and that the front and rear driveshafts are
locked together. This light will illuminate when the transfer
case is shifted into either the 4H or 4L position. There is no
light for the 2H or NEUTRAL positions on some models.
When operating your vehicle in 4L, the engine speed is
approximately three times that of the 2H or 4H positions at
a given road speed. Take care not to overspeed the engine
and do not exceed 25 mph (40 km/h).
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference will adversely affect shifting and can cause
damage to the drivetrain.
NOTE:
Do not attempt to make a shift while only the front
or rear wheels are spinning, as this can cause damage to
driveline components.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
NOTE: Delayed shifts out of four-wheel drive may be
experienced due to uneven tire wear, low or uneven tire
pressures, excessive vehicle loading, or cold temperatures.
256 STARTING AND OPERATING

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
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STARTING AND OPERATING 289

WARNING!(Continued)
•When hauling cargo or towing a trailer, do not
overload your vehicle or trailer. Overloading can
cause a loss of control, poor performance or damage
to brakes, axle, engine, transmission, steering, sus-
pension, chassis structure or tires.
• Safety chains must always be used between your
vehicle and trailer. Always connect the chains to the
hook retainers of the vehicle hitch. Cross the chains
under the trailer tongue and allow enough slack for
turning corners.
• Vehicles with trailers should not be parked on a
grade. When parking, apply the parking brake on the
tow vehicle. Put the tow vehicle transmission in
PARK. For four-wheel drive vehicles, make sure the
transfer case is not in NEUTRAL. Always, block or
chock the trailer wheels.
• GCWR must not be exceeded.
• Total weight must be distributed between the tow
vehicle and the trailer such that the following four
ratings are not exceeded:
1. GVWR
(Continued)
WARNING! (Continued)
2. GTW
3. GAWR
4. Tongue weight rating for the trailer hitch utilized.
Towing Requirements — Tires
•Do not attempt to tow a trailer while using a compact
spare tire.
• Proper tire inflation pressures are essential to the safe
and satisfactory operation of your vehicle. Refer to
“Tires” in “Servicing And Maintenance” for proper tire
inflation procedures.
• Check the trailer tires for proper tire inflation pressures
before trailer usage.
• Check for signs of tire wear or visible tire damage before
towing a trailer. Refer to “Tires” in “Servicing And
Maintenance” for the proper inspection procedure.
• When replacing tires, refer to “Tires” in “Servicing And
Maintenance” for the proper tire replacement proce-
dures. Replacing tires with a higher load carrying capac-
ity will not increase the vehicle’s GVWR and GAWR
limits.
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STARTING AND OPERATING 299

WARNING!
Raising the vehicle higher than necessary can make the
vehicle less stable. It could slip off the jack and hurt
someone near it. Raise the vehicle only enough to
remove the tire.
5. Remove the lug nuts and pull the wheel off. Install the spare wheel and lug nuts with the cone shaped end of
the nuts toward the wheel on single rear wheel (SRW)
models. On dual rear wheel models (DRW) the lug nuts
are a two-piece assembly with a flat face. Lightly tighten
the nuts. To avoid risk of forcing the vehicle off the jack,
do not fully tighten the nuts until the vehicle has been
lowered.
6. Using the lug wrench, finish tightening the nuts using a crisscross pattern. For the proper lug nut torque speci-
fications refer to “Wheel And Tire Torque Specifica-
tions” in “Technical Specifications.” If in doubt about
the correct tightness, have them checked with a torque
wrench by an authorized dealer or at a service station.
WARNING!
A loose tire or jack thrown forward in a collision or
hard stop, could endanger the occupants of the vehicle.
Always stow the jack parts and the spare tire in the
places provided.
7. Install wheel center cap (if equipped) and remove wheel blocks. Do not install chrome or aluminum wheel center
caps on the spare wheel. This may result in cap damage.
8. Lower the jack to its fully closed position. If the jack will not lower by turning the dial (thumbwheel) by hand, it
may be necessary to use the jack driver in order to lower
the jack. Stow the replaced tire, jack, and tools as
previously described.
9. Adjust the tire pressure when possible.
Dual Rear Wheels
Slots in the wheels will assist in properly orienting the
inner and outer wheels. Align these slots when assembling
the wheels for best access to the tire valve on the inner
wheel. The tires of both dual wheels must be completely off
the ground when tightening to insure wheel centering and
maximum wheel clamping.
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IN CASE OF EMERGENCY 341

SCHEDULED SERVICING
Your vehicle is equipped with an automatic oil change
indicator system. The oil change indicator system will
remind you that it is time to take your vehicle in for
scheduled maintenance.
Based on engine operation conditions, the oil change
indicator message will illuminate. This means that service
is required for your vehicle. Operating conditions such as
frequent short-trips, trailer tow, extremely hot or cold
ambient temperatures, and E85 fuel usage will influence
when the “Oil Change Required” message is displayed.
Severe Operating Conditions can cause the change oil
message to illuminate as early as 3,500 miles (5,600 km)
since last reset. Have your vehicle serviced as soon as
possible, within the next 500 miles (805 km).
Your authorized dealer will reset the oil change indicator
message after completing the scheduled oil change. If a
scheduled oil change is performed by someone other than
your authorized dealer, the message can be reset by
referring to the steps described under “Instrument Cluster
Display” in “Getting To Know Your Instrument Panel” for
further information.Gasoline Engines:
Under no circumstances should oil change intervals exceed
8,000 miles (13,000 km), twelve months or 350 hours of
engine run time, whichever comes first. The 350 hours of
engine run or idle time is generally only a concern for fleet
customers.
Severe Duty:
Change Engine Oil at 4,000 miles (6,500 km) or 350 hours of
engine run time if the vehicle is operated in a dusty and off
road environment or is operated predominately at idle or
very low engine RPM’s. This type of vehicle use is consid-
ered Severe Duty.
Once A Month Or Before A Long Trip:
•
Check engine oil level
• Check windshield washer fluid level
• Check the tire inflation pressures and look for unusual
wear or damage
• Check the fluid levels of the coolant reservoir, brake
master cylinder, power steering and automatic transmis-
sion, and fill as needed
• Check function of all interior and exterior lights
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SERVICING AND MAINTENANCE 357

Cooling System
WARNING!
You or others can be badly burned by hot engine
coolant (antifreeze) or steam from your radiator. If you
see or hear steam coming from under the hood, do not
open the hood until the radiator has had time to cool.
Never try to open a cooling system pressure cap when
the radiator is hot.
Engine Coolant Checks
Check the engine coolant (antifreeze) protection every 12
months (before the onset of freezing weather, where appli-
cable). If the engine coolant (antifreeze) is dirty or rusty in
appearance, the system should be drained, flushed and
refilled with fresh coolant. Check the front of the A/C
condenser (if equipped) or radiator for any accumulation
of bugs, leaves, etc. If dirty, clean by gently spraying water
from a garden hose vertically down the face of the A/C
condenser (if equipped) or the back of the radiator core.
Check the engine cooling system hoses for brittle rubber,
cracking, tears, cuts and tightness of the connection at the
coolant recovery bottle and radiator. Inspect the entire
system for leaks.DO NOT REMOVE THE COOLANT PRESSURE CAP
WHEN THE COOLING SYSTEM IS HOT.
Cooling System — Drain, Flush And Refill
NOTE:
Some vehicles require special tools to add coolant
properly. Failure to fill these systems properly could lead to
severe internal engine damage. If any coolant is needed to
be added to the system please contact your local autho-
rized dealer.
If the engine coolant (antifreeze) is dirty or contains visible
sediment, have an authorized dealer clean and flush with
OAT coolant (antifreeze) (conforming to MS.90032).
Refer to the “Maintenance Plan” in this section for the
proper maintenance intervals.
Selection Of Coolant
Refer to “Fluids And Lubricants” in “Technical Specifica-
tions” for further information.
382 SERVICING AND MAINTENANCE

TIRES
Tire Safety Information
Tire safety information will cover aspects of the following
information: Tire Markings, Tire Identification Numbers,
Tire Terminology and Definitions, Tire Pressures, and Tire
Loading.
Tire Markings
Tire Markings
1 — U.S. DOT Safety
Standards Code (TIN)4 — Maximum Load
2 — Size Designation 5 — Maximum Pressure
3 — Service Description 6 — Treadwear, Traction and Temperature Grades
392 SERVICING AND MAINTENANCE

NOTE:
•P (Passenger) — Metric tire sizing is based on U.S.
design standards. P-Metric tires have the letter “P”
molded into the sidewall preceding the size designation.
Example: P215/65R15 95H.
• European — Metric tire sizing is based on European
design standards. Tires designed to this standard have
the tire size molded into the sidewall beginning with the
section width. The letter Pis absent from this tire size
designation. Example: 215/65R15 96H. •
LT (Light Truck) — Metric tire sizing is based on U.S.
design standards. The size designation for LT-Metric
tires is the same as for P-Metric tires except for the letters
“LT” that are molded into the sidewall preceding the
size designation. Example: LT235/85R16.
• Temporary spare tires are designed for temporary emer-
gency use only. Temporary high pressure compact spare
tires have the letter “T” or “S” molded into the sidewall
preceding the size designation. Example: T145/80D18
103M.
• High flotation tire sizing is based on U.S. design stan-
dards and it begins with the tire diameter molded into
the sidewall. Example: 31x10.5 R15 LT.
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SERVICING AND MAINTENANCE 393