223
2008 IMPERIAL
CHASSIS INFORMATION — 10
ATC Switch:
Activating the ATC switch
reduces ECU control over engine
torque. Momentarily pressing the
ATC switch allows the ECU to
increase the amount of engine
torque applied to the drive wheel
in an ATC event. The amount of
engine torque applied to the drive
wheel will vary with the amount of
drive wheel slip versus road speed.
In an ATC event, the ECU remains
active regardless of road speed or
switch position.
ATC Indicator Light:
During normal operation, the ATC indicator
light on the dash will illuminate when the
ignition key is turned
ON
until the
fi
rst brake
application. If an ATC event occurs, the
indicator light will
fl
ash quickly. The indicator
light will
fl
ash slowly if the ATC switch is
activated.
CAUTION:
Normally the switch should remain
inactive. During an ATC event (drive
wheel slip) the ECU will automatically
optimize drive wheel traction in most
situations. Activating the switch during
periods of wheel slip can increase torque
to the spinning drive wheel. Drive train
damage can occur if the spinning drive
wheel should suddenly regain traction.
If the motorhome is stuck it is advised
to call a professional towing company
to limit the possibility of body and drive
train damage.
FRONT AXLE
While driving the motorhome, be aware of
any changes in the feel of steering and have
the system checked when noting apparent
differences. It is normal to hear some hydraulic
noise from the steering, especially when the
steering is at maximum, or while turning the
wheel when the motorhome is stationary.
Investigate any unusual or loud noises that
occur. Begin by checking the level of the
hydraulic
fl
uid. Traveling at slow speeds over
rough surfaces may cause a “clunking” noise
to emanate from the steering column, but if
noise is heard on smooth surfaces while sharply
turning back and forth, the noise should be
inspected and repaired as necessary.
Shimmy and looseness should be checked
and corrected as soon as possible. If looseness
is felt in the steering, the steering linkages can
be observed while someone turns the steering
wheel left and right. Watch the linkages for
evident play or uneven interaction between
components to help pinpoint a problem. Wheel
bearings should be cleaned and repacked with
high temperature disc brake grease every 30,000
miles. Have the steering system checked for
damage after a severe impact, such as
striking large potholes or curbs, and front-
end collisions. Observe the alignment of the
steering wheel; a change in the alignment
may indicate damage to the steering
components or suspension.
Maintenance for the system entails adequate
lubrication. Use only a hand operated grease gun
on the
fi
ttings. Grease
fi
ttings for the steering
system are found on the both ends of the drag
link (the bar connecting the steering gear to the
axle), and on the intermediate steering shaft
located between the steering wheel and steering
gear. The correct wheel alignment promotes
longer tire wear and ease of handling while
minimizing the strain on the steering system
and the axle components. Use NLGI #2 Lithium
soap base lubricant for all steering linkage and
brake components.
Alignment
Camber:
Camber, as shown, is vertical tilt of wheel as
viewed from the front of the motorhome. This is
machined into the axle when manufactured and
is not adjustable.
“Positive”
camber is an outward tilt of
the wheel at the top.
“Negative”
camber is an inward tilt of
the wheel at the top.
080375o
Located
on Driver
Console
090267
