freightliner cascadia Driver Manual page 166

Drive Axles
when performing an axle shift with the vehicle
moving.
Axle shift is a function installed on vehicles with two-
speed axles to allow the use of the low speed range
when greater traction and maximum pulling power is
needed at low engine speed (rpm).
Under normal operating conditions, the vehicle is op-
erated using the high-speed gear ratios of the axle.
Under extreme weather or off-road conditions, at low
speed and rpm and/or to pull heavy loads, the ve-
hicle must be operated using the low-speed, or re-
duction, gear ratios of the axle.
Axle Shift Switch
The axle shift switch is a two-position rocker switch
(Fig. 16.2) installed on vehicles with two-speed
axles.
06/12/2007
Fig. 16.2, Axle Shift Switch
To shift the axle from low speed to high speed, press
the top of the switch. To turn the axle shift off (switch
from high speed back to low speed), press the bot-
tom of the switch. When the axle has shifted speed,
the LED turns off.
When the panel lights are on, the AXLE SHIFT leg-
end is backlit in green.
IMPORTANT: If the LED in the switch begins to
blink during normal operation, when the switch
has not been activated, this indicates an error
condition. Bring the vehicle to an authorized
Freightliner service facility as soon as possible.
When the axle shift switch is pressed, three re-
sponses are possible: a normal response, a slow re-
sponse, and an abnormal response.
16.3
AXLE
SHIFT
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Normal Response: The LED in the switch blinks until
the axle shifts speed. At this point, the LED comes
on steady and stays illuminated. In normal operation,
the axle may shift so quickly that the blinking of the
switch is barely noticeable.
If operation of the switch is not possible for any rea-
son (interaxle lock is on, ignition is turned off, etc.),
the LED will stop blinking and turn off.
Slow Response: If operation of the switch is slowed
for any reason (by cold weather, low air pressure,
etc.), the switch will continue to blink until the axle
shifts. As in the normal response, the LED comes on
steady and stays illuminated.
Abnormal Response: If the LED blinks for more than
30 seconds, the axle shift function/mechanism may
not be operating correctly. Bring the vehicle to an
authorized Freightliner service facility for testing.
Axle Switch Interlock
NOTE: On vehicles with tandem drive axles,
there is an interlock that prevents an axle from
shifting speed whenever the interaxle lock is on.
If the axle shift switch is pressed when the interaxle
lock is on, the axle shift will not be completed. The
LED does the following:
•
If the LED is off, the LED comes on briefly and
turns off again.
•
If the LED is on, it stays on.
To complete the axle shift, turn off the interaxle lock
and press the axle shift switch again. If still needed,
the interaxle lock can then be reactivated.