2021 RAM CHASSIS CAB brake

388SERVICING AND MAINTENANCE
Fluid Level Check — Eight-Speed
Transmission
The fluid level is preset at the factory and does
not require adjustment under normal operating
conditions. Routine fluid level checks are not
required, therefore the transmission has no
dipstick. An authorized dealer can check your
transmission fluid level using special service
tools.
If you notice fluid leakage or transmission
malfunction, visit an authorized dealer
immediately to have the transmission fluid
level checked. Operating the vehicle with
an improper fluid level can cause severe
transmission damage.
Fluid Level Check — Six-Speed
Transmission
It is best to check the fluid level when the
transmission is at normal operating
temperature (158-176°F / 70-80°C). This
normally occurs after at least 15 miles (25 km)
of driving. At normal operating temperature the
fluid cannot be held comfortably between the
fingertips. You can read the transmission sump
temperature in the instrument cluster screen
Ú page 90. Use the following procedure to check the
transmission fluid level properly:

1. Monitor the transmission temperature
using the instrument cluster display, and
operate the vehicle as required to reach
the normal operating temperature. If the
transmission is not functioning properly, or
the vehicle cannot be driven, see the NOTE
and CAUTION below about checking the
fluid level at colder temperatures.

2. Park the vehicle on level ground.
3. Run the engine at normal idle speed for at least 60 seconds, and leave the engine
running for the rest of this procedure.
4. Fully apply the parking brake, and press the brake pedal.
5. Place the gear selector momentarily into each gear position (allowing time for the
transmission to fully engage in each
position), ending with the transmission in
PARK.
6. Remove the dipstick, wipe it clean and reinsert it until seated.
CAUTION!
Do not use chemical flushes in your
transmission as the chemicals can damage
your transmission components. Such damage
is not covered by the New Vehicle Limited
Warranty.
CAUTION!

If a transmission fluid leak occurs, visit an
authorized dealer immediately. Severe
transmission damage may occur. An authorized
dealer has the proper tools to adjust the fluid
level accurately.

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SERVICING AND MAINTENANCE389
7. Remove the dipstick again and note the
fluid level on both sides. The fluid level
reading is only valid if there is a solid
coating of oil on both sides of the dipstick.
Note that the holes in the dipstick will be full
of fluid if the actual level is at or above the
hole. The fluid level should be between the
“HOT” (upper) reference holes on the
dipstick at normal operating temperature.
If the fluid level is low, add fluid through the
dipstick tube to bring it to the proper level.
Do not overfill. Use ONLY the specified fluid
Ú page 444. After adding any quantity of oil
through the dipstick tube, wait a minimum
of two minutes for the oil to fully drain into
the transmission before rechecking the
fluid level.
NOTE:

If it is necessary to check the transmission below
the operating temperature, the fluid level should be
between the two “COLD” (lower) holes on the
dipstick with the fluid at 60-70°F / 16-21°C. Only
use the COLD region of the dipstick as a rough refer -
ence when setting the fluid level after a transmis -sion service or fluid change. Re-check the fluid level,
and adjust as required, once the transmission
reaches normal operating temperature.

8. Reinsert the dipstick. Check for leaks.
Release the parking brake.
NOTE:

If it is necessary to check the transmission below
the operating temperature, the fluid level should be
between the two COLD (lower) holes on the dipstick
with the fluid at 68-86°F / 20-30°C. Only use the
COLD region of the dipstick as a rough reference
when setting the fluid level after a transmission
service or fluid change. Re-check the fluid level, and
adjust as required, once the transmission reaches
normal operating temperature.

Fluid And Filter Changes — Eight-Speed
Transmission
Under normal operating conditions, the fluid
installed at the factory will provide satisfactory
lubrication for the life of the vehicle.

Routine fluid and filter changes are not required.
However, change the fluid and filter if the fluid
becomes contaminated (with water, etc.), or if the
transmission is disassembled for any reason.

Fluid And Filter Changes — Six Speed
Transmission
For the proper maintenance intervals
Ú page 354.
In addition, change the fluid and filters if the
fluid becomes contaminated (with water, etc.),
or if the transmission is disassembled for any
reason.
CAUTION!
If the fluid temperature is below 50°F (10°C)
it may not register on the dipstick. Do not add
fluid until the temperature is elevated enough
to produce an accurate reading. Run the
engine at idle, in PARK, to warm the fluid.
CAUTION!
If the fluid temperature is below 50°F (10°C)
it may not register on the dipstick. Do not add
fluid until the temperature is elevated enough
to produce an accurate reading. Run the
engine at idle, in PARK, to warm the fluid.
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SERVICING AND MAINTENANCE395
Power Distribution Center
The Power Distribution Center is located in the
engine compartment near the battery. This
center contains cartridge fuses, micro fuses,
relays, and circuit breakers. A description of
each fuse and component may be stamped on
the inside cover, otherwise the cavity number of
each fuse is stamped on the inside cover that
corresponds to the following chart.

Power Distribution Center Location

Cavity Cartridge FuseMicro Fuse Description
F01– –Spare
F02 60 Amp Yellow –ABS Pump Motor (HD Only)
F03 60 Amp Yellow –Rad Fan – If Equipped
F04 50 Amp Red 400W Inverter – If Equipped
F05 40 Amp Green –Compressor For Air Suspension – If Equipped
F06 40 Amp Green –Steering Torque Overlay Module (STOM)
F07 40 Amp Green –Starter Solenoid
F08 20 Amp Blue –NOX Sensor – If Equipped
F09 40 Amp Green –Diesel / Fuel Heater – If Equipped
F09 30 Amp Pink –Gas / Brake Vacuum Pump – If Equipped
F10 40 Amp Green –CBC #2 / Ext Lights
F11 40 Amp Green –Brake System Module (ECU and Valves)
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396SERVICING AND MAINTENANCE
F1240 Amp Green –CBC #3 / Pwr Locks
F13 40 Amp Green –Blower Motor
F14 40 Amp Green –CBC #4 / Ext Lights
F15 30 Amp Pink –Power Side Steps — If Equipped
F16 30 Amp Pink –Smart-Bar Module – If Equipped
F17 30 Amp Pink –Winch Control Module – If Equipped
F19 30 Amp Pink –Diesel SCR Feed– If Equipped
F20 30 Amp Pink –Passenger Door Module
F21 30 Amp Pink –Drive Train Control Module
F22 20 Amp Blue –Gas / ECM– If Equipped
F22 25 Amp White –Diesel PCM – If Equipped
F23 30 Amp Pink –CBC #1 / Int Light
F24 30 Amp Pink –Driver Door Module
F25 30 Amp Pink –Front Wiper
F26 — –Spare
F27 — –Spare
F28 20 Amp Blue –Trailer Tow Backup Lights – If Equipped
F29 20 Amp Blue –Trailer Tow Parking Lights – If Equipped
F30 30 Amp Pink –Trailer Tow Receptacle / Trailer Tow (Separate E-Brake) / Trailer Tow
F31 – –Spare
Cavity Cartridge Fuse Micro Fuse Description

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SERVICING AND MAINTENANCE397
F32– –Spare
F33 20 Amp Blue –Trans Control Module – If Equipped
F34 30 Amp Pink –Vehicle System Interface Module #2 – If Equipped
F35 30 Amp Pink –Sunroof – If Equipped
F36 30 Amp Pink –Electric Back Light – If Equipped
F37 30 Amp Pink –Diesel Frame / Fuel Heater #2– If Equipped
F38 30 Amp Pink –Integrated Trailer Brake Module – If Equipped
F39 – –Spare
F40 –10 Amp Red Ventilated Seats – If Equipped
F41 –10 Amp Red Active Grille Shutter / Active Air Dam – If Equipped
F42 –20 Amp Yellow Horn
F43 –15 Amp Blue Heated Steering Wheel – If Equipped
F44 –10 Amp Red Diagnostic Port
F46 –10 Amp Red Upfitters Relay Coil – If Equipped
F47 – –Spare
F48 – –Spare
F49 –10 Amp Red IP Cluster / CSG
F50 –20 Amp Yellow Air Suspension Control Module – If Equipped
F51 –10 Amp RedIgnition Node Module / Keyless Ignition Node Module, Radio Frequency
Hub Module / Electric Steering Column Lock - If Equipped
F52 –5 Amp Tan Battery Sensor
Cavity Cartridge Fuse Micro Fuse Description
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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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431
TECHNICAL SPECIFICATIONS
VEHICLE IDENTIFICATION NUMBER (VIN)
The VIN is found on the left front corner of
the instrument panel, visible through the
windshield.
Vehicle Identification Number

NOTE:
It is illegal to remove or alter the VIN.
BRAKE SYSTEM
If power assist is lost for any reason (for
example, repeated brake applications with
the engine off), the brakes will still function.
However, you will experience a substantial
increase in braking effort to stop the vehicle.

If either the front or rear hydraulic system loses
normal braking capability, the remaining system
will still function with some loss of overall braking
effectiveness. This will be evident by increased
pedal travel during application, greater pedal
force required to slow or stop, and activation of
the “Brake Warning Light” and/or the “ABS
Warning Light” during brake use.

HYDRAULIC BRAKE ASSIST — IF
E
QUIPPED
The brake system power assist is provided by a
hydro-boost unit which shares fluid with the
power steering system. You may experience
some clicking or hissing noises from the
hydro-boost system during hard braking
conditions.
NOTE:
Under cold temperatures, pedal effort will be
higher than normal until the power steering fluid
reaches operating temperature.
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