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Wheel Nuts
All wheel nuts should be tightened occasionally to elimi-
nate the possibility of wheel studs being sheared or the bolt
holes in the wheels becoming elongated. This is especially
important during the first few hundred miles/kilometers
of operation to allow the wheel nuts to become properly
set. All wheel nuts should first be firmly seated against the
wheel. The wheel nuts should then be tightened to recom-
mended torque. Tighten the wheel nuts to final torque in
increments. Progress around the bolt circle, tightening the
wheel nut opposite to the wheel nut just previously
tightened until final torque is achieved.
To Stow The Flat Or Spare — If Equipped
Refer to Upfitters Body Builders Guide for information on
stowing your spare tire (if equipped).
Hub Caps/Wheel Covers — If Equipped
The hub caps must be removed before raising the vehicle
off the ground.
CAUTION!
Use extreme caution when removing the front and rear
center caps. Damage can occur to the center cap and/or
the wheel if screwdriver type tools are used. A pulling
motion, not a pry off motion, is recommended to
remove the caps.
For single rear wheel (SRW) models, use the flat blade on
the end of the lug wrench to pull the hub cap off. Insert the
blade end into the pull off notch and carefully pull the hub
cap off with a back and forth motion.
On 3500 models with dual rear wheels (DRW), you must
first remove the hub caps. The jack handle driver has a
hook at one end that will fit in the pull off notch of the rear
hub caps. Position the hook and pull straight out on the
ratchet firmly. The hub cap should pop off. The wheel skins
can now be removed. For the front hub cap, use the flat
blade on the end of the lug wrench to pull the caps off. The
wheel skin can now be removed.
344 IN CASE OF EMERGENCY
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Hydraulic Brake Assist
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.
WHEEL AND TIRE TORQUE SPECIFICATIONS
Proper lug nut/bolt torque is very important to ensure that
the wheel is properly mounted to the vehicle. Any time a
wheel has been removed and reinstalled on the vehicle, the
lug nuts/bolts should be torqued using a properly cali-
brated torque wrench using a high quality six sided (hex)
deep wall socket.
Torque Specifications
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
**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.
9
TECHNICAL SPECIFICATIONS 427
Page 430 of 529
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).
Do not oil wheel studs. For chrome wheels, do not substi-
tute with chrome plated wheel nuts. Retighten the wheel nuts in the same sequence to the
torques listed in the table. Go through the sequence a
second time to verify that specific torque has been
achieved. Retighten to specifications after 25 miles (40 km)
and check the lug nut/bolt torque to be sure that all the lug
nuts/bolts are properly seated against the wheel.
Oil Interface Location
Wheel Mounting Surface
428 TECHNICAL SPECIFICATIONS
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It is recommended that wheel stud nuts be kept torqued to
specifications at all times. Torque wheel stud nuts to
specifications at each lubrication interval.
All wheel nuts should be tightened occasionally to elimi-
nate the possibility of wheel studs being sheared or the bolt
holes in the wheels becoming elongated. This is especially
important during the first few hundred miles/kilometers
of operation to allow the wheel nuts to become properly
set. All wheel nuts should first be firmly seated against thewheel. The wheel nuts should then be tightened to recom-
mended torque. Tighten the wheel nuts to final torque in
increments. Progress around the bolt circle, tightening the
wheel nut opposite to the wheel nut just previously
tightened until final torque is achieved.
WARNING!
To avoid the risk of forcing the vehicle off the jack, do
not tighten the lug nuts fully until the vehicle has been
lowered. Failure to follow this warning may result in
personal injury.
FUEL REQUIREMENTS
6.4L Engine
Do not use E-85 flex fuel or ethanol blends greater than
15% in this engine.
This engines is designed to meet all emis-
sions regulations and provide satisfactory
fuel economy and performance when us-
ing high quality unleaded gasoline hav-
ing a posted octane number range of 87 to
89 as specified by the (R+M)/2 method.
The use of 89 octane “Plus” gasoline is
recommended for optimum performance and fuel economy.
8/10 Lug Nuts/Bolts Torque Patterns
1 — 10 Bolt Pattern
2 — 8 Bolt Pattern9
TECHNICAL SPECIFICATIONS 429