Differential Locks (Canada Only); A Few Words About - Mercedes-Benz 2009 GL320 BlueTEC Operator's Manual

Controls in detail

Differential locks (Canada only)

Indicator lamp on LOW RANGE switch
2
goes out, indicating that the LOW
1
RANGE mode has been deactivated.
i
You can cancel the procedure by pressing
the LOW RANGE switch again while the
indicator lamp is flashing.
For messages in the multifunction display,
see the "Practical hints" section
( Y page 352).
144
Differential locks (Canada only)
Vehicles with enhanced off-road package are
equipped with automatic locks for the center
and rear axle differential to improve vehicle
traction.
The center differential compensates for
differences in wheel rotation between the
front and rear axle.
The rear axle differential compensates
differences between the rear wheels.
i
At the front axles, the 4-ETS system
compensates for any traction problems.
For more information on off-road driving, see
"Off-road driving" ( Y page 303).
A few words about differentials and
differential locks
When a vehicle negotiates a turn, wheels on
the outside of the curve must travel farther
and rotate faster than the inside wheels. The
differential, the operation of a set of gears
that allows the powered wheels in a vehicle
to turn at different speeds, makes this
essential function possible.
The drawback is that the differential also
sends most of the engine's power to the
wheel with the least load or strain on it. For
example, if one of a vehicle's powered wheels
sits on a patch of snow and spins because
there is no traction, all of the engine's power
will go to that wheel because the power will
take the path of least resistance. Meanwhile,
the opposite wheel, sitting on dry pavement
where it could get enough grip to start the
vehicle moving, sits idle because it receives
no power.
The 4-ETS addresses this problem and
provides for good control and steering ability
by automatically slowing the slipping wheel
and thus increasing the power to the other
non-slipping drive wheels to get the vehicle
®
moving. The ESP and the 4-ETS in this
vehicle feature such intelligent limited-slip
differential technology, ideally suited for on-
road and light off-road driving. Transfer case
position LOW ( Y page 142) also enhances off-
road driving capabilities.
More extreme off-road conditions may call for
another solution, engaging a differential lock
or preventing the differential from operating
altogether. This vehicle comes with two
differential locks: transfer case (center) and
rear. Each can be engaged simply by
operating the rotary switch located on the
center console ( Y page 145). When the
transfer case (center) differential is locked,