gear and "SM" (system malfunction), there is a prob-
lem which may or may not be apparent to the driver.
Bring the vehicle at once to a safe stopping place
and call an authorized Freightliner service facility for
assistance.
Clutch Overload
If the "TRANS TEMP" telltale light comes on while
driving and the current gear indicator begins to flash
between the current gear and "CO" (clutch overload),
the clutch has begun to overheat.
The clutch overload may have been caused by im-
proper driving practices such as frequent and rapid
start/stop driving, or hillholding with the throttle pedal.
In this case, allow the clutch to cool, and continue
on, but cease the improper driving practices.
If the clutch overload message returns or continues,
the clutch is worn or damaged. Bring the vehicle at
once to a safe stopping place and call an authorized
Freightliner service facility for assistance.
Low Hydraulic Fluid Level
IMPORTANT: The only hydraulic fluid permitted
in this system is Pentosin CHF 11S. No other
fluid can be substituted.
If the "CHECK TRANS" telltale light comes on while
driving and the current gear indicator begins to flash
between the current gear and "FL" (fluid level), there
has been an unusual loss of hydraulic fluid. Bring the
vehicle at once to a safe stopping place and call an
authorized Freightliner service facility for assistance.
The hydraulic reservoir holds about 1.05 quarts (one
liter) of Pentosin CHF 11S.
NOTE: After hydraulic fluid loss, a special pro-
cedure is required to fill the hydraulic reservoir.
This procedure must be carried out by an autho-
rized Freightliner service facility.
Meritor
™
Drive Axles
Refer to the Meritor website for additional informa-
tion,
Drive Axles With Differential Lock
The Meritor driver-controlled differential lock feature
(side-to-side wheel lock, traction control, or traction
equalizer) is available on single-drive or dual-drive
rear axles. It is available on both axles of a dual-
drive vehicle, or on one only. It is only available on
drive axles. Differential lock must only be used under
adverse road conditions where greater traction is
needed. With differential lock on, the turning radius is
increased and vehicle handling is affected. The differ-
ential lock switch (
) allows the driver to lock
the wheels on the same axle together. The red differ-
ential lock warning light illuminates on the dash mes-
sage center when differential lock is engaged.
Differential lock provides maximum traction under
slippery conditions. When the differential lock is en-
gaged, the clutch collar completely locks the differen-
tial case, gearing, and axle shafts together, maximiz-
ing the traction of both wheels and protecting against
spinout.
Under normal traction conditions, do not use the dif-
ferential lock feature.
Differential Lock Switch
NOTICE
Differential lock should only be engaged when
the vehicle is stopped or moving slowly at low
throttle. This will prevent internal axle damage.
Normally, when differential lock is available on dual-
drive vehicles, one switch activates the lock on both
rear drive axles. As an option, it possible to have two
differential lock switches, one for the forward rear
and one for the rearmost drive axle. It is also pos-
sible for some vehicles to have differential lock on
only one of the drive axles.
A two-position guarded rocker switch (
) con-
trols differential lock, causing the wheels on each
axle governed by the switch to rotate together. To
lock the wheels together, press the upper half of the
rocker momentarily (at the red LED). To unlock the
wheels, press the upper half of the rocker again.
10/26/2001
f610596
Fig. 8.21, Differential Lock Switch
Drivetrain
8.29
