Mercedes-Benz G-Class 2012 Owners Manual - Manual (Page 150)

Differential locks
General information
Differential locks improve the traction of the
vehicle.
G WARNING
Never drive on firm road surfaces with
differential locks engaged. Never drive on
narrow bends with front-axle differential locks
engaged. With differential locks engaged, the
vehicle's ability to steer is severely restricted
and the danger of accidents is therefore
higher.
Do not engage or disengage differential locks
while driving on a bend. The vehicle may
otherwise make a jerking movement. You
could thus lose control of the vehicle and
cause an accident.
If you select a differential lock, ABS, 4ETS,
ESP
® and BAS will be deactivated.
Your vehicle is equipped with a differential
lock for:
R
the transfer case: this controls the balance
between the front and rear axles.
R the rear axle: this controls the balance
between the wheels on the rear axle.
R
the front axle: this controls the balance
between the wheels on the front axle.
! In order to avoid damage to the transfer
case, you must operate the vehicle on a
dynamometer (1-axle dynamometer) only
if:
R
the axle not driven on is jacked up
or
R
the corresponding propeller shaft is
disconnected
and
R
the differential lock of the transfer case
is engaged.
Otherwise, the transfer case can be
damaged.
Information about differentials and
differential locks
When the vehicle drives around a corner, the
wheels on the outside of the bend must cover
a greater distance. Therefore, the wheels turn
more rapidly than on the inside. The
differential, a transmission in the drivetrain,
balances out the different rotational speeds
and therefore enables driving through bends.
The disadvantage of a differential is that more
power is transferred to the wheels that have
the least grip. Example: a wheel on a driven
axle stands on snow-covered ground and thus
has no traction. This wheel receives the
strongest driving power from the differential,
as the force progression takes the path of
least resistance. The opposite wheel on this
axle, however, which stands on firm ground
and could therefore allow propulsion,
receives no driving power. 4ETS eliminates
this disadvantage. It provides good
steerability by automatically braking the
spinning wheel. As a result, 4ETS directs
more driving power to the wheel standing on
firm ground, which is therefore able to
provide propulsion.
ESP® and 4ETS are traction systems that are
ideal for road driving and suitable for light off-
road driving. Off-road gear
LOW likewise
improves off-road capabilities.
Moreover, the more difficult conditions in off-
road driving require further measures such as
locking one or several differentials. Your
vehicle is equipped with three differential
locks:
R a central differential lock for the transfer
case,
R
a differential lock for the front axle and
R
a differential lock for the rear axle.
Each differential lock can be engaged with the
respective switch on the center console.
When the central differential lock for the
transfer case is locked, the speed of the front
wheels is equal to that of the rear wheels.
When the differential for the rear axle is
locked, both rear wheels turn equally fast,
148
Off-road driving systems
Driving and parking