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4. Press the UP or DOWN button on the steering wheeluntil “VEHICLE SETTINGS” appears on the screen.
5. Press the RIGHT arrow on the steering wheel to enter “VEHICLE SETTINGS”.
6. Press the UP or DOWN buttons until Trailer Brake Type appears on the screen.
NOTE: 1500 Models Only – Light Electric and Heavy
Electric will only be available due to the tow capacities of
the vehicle.
7. Press the RIGHT arrow and then press the UP or DOWN buttons until the proper Trailer Brake Type
appears on the screen.
8.
In a traffic-free environment, tow the trailer on a dry,
level surface at a speed of 20–25 mph (30–40 km/h) and
squeeze the manual brake control lever completely.
9. If the trailer wheels lockup (indicated by squealing tires), reduce the GAIN setting; if the trailer wheels
turn freely, increase the GAIN setting.
Repeat Steps 8 and 9 until the GAIN setting is at a point
just below trailer wheel lockup. If towing a heavier
trailer, trailer wheel lockup may not be attainable even
with the maximum GAIN setting of 10.
Light
Electric Heavy
ElectricLight
EOHHeavy
EOH
Type of
Trailer
Brakes Electric
Trailer
BrakesElectric
Trailer
BrakesElectric
over
Hy-
draulic
Trailer
BrakesElectric
over Hy-
draulic
Trailer
Brakes
Load *Under 10,000 lbs *Above
10,000 lbs *Under
10,000 lbs *Above
10,000lbs
556 STARTING AND OPERATING
Page 592 of 743

end of the wheel nuts toward the wheel. To avoid the
risk of forcing the vehicle off the jack, do not fully
tighten the wheel nuts until the vehicle has been
lowered.
6. Using the lug wrench, finish tightening the wheel nuts using a crisscross pattern. The correct wheel nut
tightness for a cone type wheel nut is 120–140 ft lbs
(160–190 N·m) torque, for a flanged type wheel nut is
130–160 ft lbs (175–215 N·m) torque. If in doubt about
the correct tightness, have them checked with a torque
wrench by your authorized dealer or at a service
station.
WARNING!
A loose tire or jack thrown forward in a collision or
hard stop could injure someone in the vehicle. Al-
ways stow the jack parts and the extra tire and wheel
in the places provided. 7. Install the wheel center cap and remove the 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 bottle jack will not lower by turning the dial (thumbwheel)
by hand, it may be necessary to use the jack drive tube
in order to lower the jack. Stow the replaced tire, jack,
and tools as previously described.
9. Adjust the tire pressure when possible.
NOTE: Do not oil wheel studs. For chrome wheels, do
not substitute with chrome plated wheel nuts.
590 WHAT TO DO IN EMERGENCIES
Page 598 of 743

back-and-forth motion, loosen the wheel skin. Repeat this
procedure around the tire until the skin pops off.
Replace the wheel skins first using a rubber mallet. When
replacing the hub caps, tilt the cap retainer over the lug
nut bolt circle and strike the high side down with a
rubber mallet. Be sure that the hub caps and wheel skins
are firmly seated around the wheel.
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 isespecially 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 recommended 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. Recommended torques are shown in the fol-
lowing chart.
Type
Nut Stud
Size Hex Size Torque
Ft LbsTorque
Newton Meters
Cone M14 x 1.5 22 mm120-140 160-190
Flanged M14 x 1.5 22 mm130-160 175-215
596 WHAT TO DO IN EMERGENCIES
Page 610 of 743

5. Remove the wheel nuts and pull the wheel off. Onsingle rear-wheel (SRW) trucks, install the spare wheel
and wheel nuts with the cone shaped end of the wheel
nuts toward the wheel. On 3500 dual rear-wheel
models (DRW) the wheel nuts are a two-piece assem-
bly with a flat face. Lightly tighten the wheel nuts. To
avoid the risk of forcing the vehicle off the jack, do not
fully tighten the wheel nuts until the vehicle has been
lowered.
6. Using the lug wrench, finish tightening the wheel nuts using a crisscross pattern. The correct wheel nut
tightness for a cone type wheel nut is 120–140 ft lbs
(160–190 N·m) torque, for a flanged type wheel nut is
130–160 ft lbs (175–215 N·m) torque. If in doubt about
the correct tightness, have them checked with a torque
wrench by your authorized dealer or at a service
station.WARNING!
A loose tire or jack thrown forward in a collision or
hard stop could injure someone in the vehicle. Al-
ways stow the jack parts and the extra tire and wheel
in the places provided.
7.
Install the wheel center cap and remove the 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 bottle jack will not lower by turning the dial (thumbwheel)
by hand, it may be necessary to use the jack drive tube
in order to lower the jack. Stow the replaced tire, jack,
and tools as previously described.
9. Adjust the tire pressure when possible.
NOTE: Do not oil wheel studs. For chrome wheels, do
not substitute with chrome plated wheel nuts.
608 WHAT TO DO IN EMERGENCIES
Page 617 of 743
TypeNut Stud
Size Hex Size Torque
Ft LbsTorque
Newton Meters
Cone M14 x 1.5 22 mm120-140 160-190
Flanged M14 x 1.5 22 mm130-160 175-215
8-Stud — Dual Rear Wheels
Dual wheels are flat-mounted and 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.
Oiling Location
6
WHAT TO DO IN EMERGENCIES 615
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