four wheel drive MERCEDES-BENZ G500 2004 W463 Owner's Manual

149 Controls in detail
Differential locks
A few words about differentials and differential locks
When a vehicle negotiates a turn, wheels
on the outside of the curve must travel far-
ther 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 pos-
sible.
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 en-
gine’s power will go to that wheel because
the power will take the path of least resis-
tance. Meanwhile, the opposite wheel, sit-
ting on dry pavement where it could get
enough grip to start the vehicle moving,
sits idle because it receives no power.The Electronic Traction System (ETS) ad-
dresses this problem and provides for
good control and steering ability by auto-
matically slowing the slipping wheel and
thus increasing the power to the other
non-slipping drive wheels to get the vehicle
moving. The ESP and ETS in this vehicle
feature such intelligent limited-slip differ-
ential technology, ideally suited for
on-road and light off-road driving. Transfer
case position LOW (
page 145) also en-
hances off-road driving capabilities
(
page 213).
More extreme off-road conditions may call
for another solution, engaging a differen-
tial lock or preventing the differential from
operating altogether. As part of its stan-
dard equipment, this vehicle comes with
three differential locks: front, transfer case
(center) and rear. Each can be engaged
simply by pushing dashboard-mounted
buttons in sequential order (center, rear,
front) (
page 150). When the transfer
case (center) differential is locked, half of
the engine’s power is automatically distrib-
uted to the front wheels and half to the rear wheels. When the rear differential is
locked, power going to the rear wheels is
equally distributed, so that both rear
wheels turn at the same speed and torque.
When the front differential is locked, all
four wheels now turn with equal power and
torque. Please be aware that engaging the
differential locks will significantly reduce
the steering ability of the vehicle.
For your safety and the safety of others
and to prevent damage to the vehicle, the
differential locks must not be engaged
when driving on paved roads. It is impor-
tant to understand that during
on-road/paved driving, differentials are
absolutely necessary for providing the es-
sential control and steering ability of the
vehicle. The differential locks, therefore,
must not be engaged when driving on
paved roads and should only be used to
the extent necessary to negotiate off-road
conditions which cannot be handled by the
systems (automatic 4-ETS, the ESP, manu-
al switch position “LOW” of transfer case)
this vehicle comes equipped with.

211 Operation
Driving instructions
Tire traction
The safe speed on a wet, snow covered or
icy road is always lower than on a dry road.
You should pay particular attention to the
condition of the road whenever the outside
temperatures are close to the freezing
point.
Mercedes-Benz recommends M+S rated
radial-ply tires with a minimum tread depth
of approximately
1⁄6in (4 mm) for the win-
ter season for all four wheels to ensure
normal balanced handling characteristics.
On packed snow, they can reduce your
stopping distance as compared with sum-
mer tires.Stopping distance, however, is still consid-
erably greater than when the road is not
covered with snow or ice. Exercise appro-
priate caution.
Tire speed rating
Despite of the tire speed rating, local
speed limits should be obeyed. Use pru-
dent driving speeds appropriate to prevail-
ing conditions.Your vehicle is factory equipped with
“V”-rated tires, which have a speed rating
of 149 mph (240 km/h).
An electronic speed limiter prevents your
vehicle from exceeding a speed of
130 mph (210 km / h).
Warning!
G
If ice has formed on the road, tire traction
will be substantially reduced. Under such
weather conditions, drive, steer and brake
with extreme caution.
!Avoid spinning of one drive wheel. This
may cause serious damage to the
drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
Warning!
G
Even when permitted by law, never operate
a vehicle at speeds greater than the maxi-
mum speed rating of the tires.
Exceeding the maximum speed for which
tires are rated can lead to sudden tire fail-
ure, causing loss of vehicle control and pos-
sibly resulting in an accident and/or serious
injury and possible death, for you and for
others.iFor information on tire speed rating for
winter tires, see “Winter tires”
(page 240).

240 OperationWinter driving
Winter drivingBefore the onset of winter, have your vehi-
cle winterized at an authorized
Mercedes-Benz Light Truck Center. This
service includes:

Check of anticorrosion and antifreeze
concentration.


Addition of cleaning concentrate to the
water of the windshield and headlamp
cleaning system. Add MB Concentrate
“S” to a premixed windshield washer
solvent/antifreeze which is formulated
for below freezing point temperatures
(page 339).


Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to ensure
the engine can be started even at low
ambient temperatures.


Tire change. Mercedes-Benz recom-
mend M+S rated radial-ply tires with a
minimum tread depth of approximately 1⁄6in (4 mm) on all four wheels for the
winter season.
Winter tires
Always use winter tires at temperatures
below 45°F (7°C) and whenever wintry
road conditions prevail. Use of winter tires
is the only way to achieve the maximum ef-
fectiveness of the ABS, ESP, EBB and
4-ETS in winter operation.
For safe handling, make sure all winter
tires mounted are of the same make and
have the same tread design.
Always observe the speed rating of the
winter tires installed on your vehicle. If the
maximum speed for which your tires are
rated is below the speed rating of your ve-
hicle, you must place a notice to this effect
where it will be seen by the driver. Such no-tices are available at your tire dealer or any
authorized Mercedes-Benz Light Truck
Center.
Block heater (Canada only)
The engine is equipped with a block heat-
er.
The electrical cable may be installed at
your authorized Mercedes-Benz Center.
Warning!
G
Winter tires with a tread depth under
1⁄6in
(4 mm) must be replaced. They are no long-
er suitable for winter operation.
Warning!
G
If you use your spare tire when winter tires
are fitted on the other wheels, be aware that
the difference in tire characteristics may
very well impair turning stability and that
overall driving stability may be reduced.
Adapt your driving style accordingly.
Have the spare tire replaced with a winter
tire at the nearest authorized
Mercedes-Benz Light Truck Center.

241 Operation
Winter driving
Snow chains
Snow chains should only be driven on
snow-covered roads at speeds not to ex-
ceed 30 mph (50 km/h). Remove chains
as soon as possible when driving on roads
without snow. Observe the following guidelines when us-
ing snow chains:


Use of snow chains is not permissible
on all wheel/tire combinations.


Snow chains should only be used on all
four wheels. With only two chains avail-
able, they should be mounted on the
rear wheels. Follow the manufacturer’s
mounting instructions.


Only use snow chains that are ap-
proved by Mercedes-Benz. Your autho-
rized Mercedes-Benz Light Truck
Center will be glad to advise you on this
subject.


Use of snow chains may be prohibited
depending on location. Always check
local and state laws before installing
snow chains.
iWhen driving with snow chains, you
may wish to deactivate the ESP
(page 79) before setting the vehicle
in motion. This will improve the
vehicle’s traction.