2007 MERCEDES-BENZ G500 power steering

174 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
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 Electronic Traction System (4-ETS)
addresses 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 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 (
page 170) also
enhances off-road driving capabilities
(
page 253).
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
switches in sequential order (center, rear,
front) (
page 175). When the transfer
case (center) differential is locked, half of
the engine’s power is automatically
distributed 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
important to understand that during
on-road/paved driving, differentials are
absolutely necessary for providing the
essential 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®,
manual switch position “LOW” of transfer
case) this vehicle comes equipped with.

225 Controls in detail
Useful features
Heated steering wheel
The steering wheel heating warms up the
leather area of the steering wheel.
The stalk is located on the lower left-hand
side of the steering wheel.
1Switching on
2Switching off
3Indicator lampSwitching on
Switch on the ignition (page 39).
Turn switch at the tip of stalk in
direction of arrow1.
The steering wheel is heated.
Indicator lamp3 comes on.Switching off
Turn switch at the tip of stalk in
direction of arrow2.
The heated steering wheel is switched
off.
Indicator lamp3 goes out.
For information on adjusting the steering
wheel, see “Steering wheel” (
page 44).
iThe steering wheel heating is temporarily
suspended while the indicator lamp3 remains
on when

the temperature of the vehicle interior is
above 86°F (30°C)

the temperature of the steering wheel is
above 95°F (35°C)
When these conditions do not apply anymore,
steering wheel heating continues.
iIndicator lamp3 flashes or goes out

in case of power surge or undervoltage

in case of a steering wheel heating
malfunction
iThe steering wheel heating switches off
automatically when you remove the SmartKey
from the starter switch.

246 Operation
Driving instructions
Power assistance
BrakesTo help prevent brake disk corrosion after
driving on wet road surfaces (particularly
salted roads), it is advisable to brake the
vehicle with considerable force prior to
parking. The heat generated serves to dry
the brakes.
If your brake system is normally only
subjected to moderate loads, you should
occasionally test the effectiveness of the
brakes by applying above-normal braking
pressure at higher speeds. This will also
enhance the grip of the brake pads.
Warning!G
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the
vehicle.
Warning!G
After driving in heavy rain for some time
without applying the brakes or through
water deep enough to wet brake compo-
nents or salty road conditions, the first brak-
ing action may be somewhat reduced and
increased pedal pressure may be necessary
to obtain expected braking effect. Maintain
a safe distance from vehicles in front.
Resting your foot on the brake pedal will
cause excessive and premature wear of the
brake pads.
It can also result in the brakes overheating,
thereby significantly reducing their effec-
tiveness. It may not be possible to stop the
vehicle in sufficient time to avoid an acci-
dent.
!Operational or performance test must only
be conducted on a two-axle dynamometer. If
such tests are necessary, contact an authorized
Mercedes-Benz Light Truck Center. You could
otherwise seriously damage the brake system or
the transfer case which is not covered by the
Mercedes-Benz Limited Warranty.
!Because the ESP® operates automatically,
the engine and ignition must be shut off
(SmartKey in starter switch position0 or1)
when testing the parking brake on a brake test
dynamometer and such testing should be no
longer than 10 seconds.
Active braking action through the ESP
® may
otherwise seriously damage the brake system
which is not covered by the Mercedes-Benz
Limited Warranty.
Warning!G
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.

304 Operation
Tires and wheels
Tire ply material
1Plies in sidewall
2Plies under tread
This marking tells you about the type of
cord and number of plies in the sidewall
and under the tread.Tire and loading terminology
Accessory weight
The combined weight (in excess of those
standard items which may be replaced) of
automatic transmission, power steering,
power brakes, power windows, power
seats, radio, and heater, to the extent that
these items are available as
factory-installed equipment (whether
installed or not).
Air pressure
The amount of air inside the tire pressing
outward on each square inch of the tire.
Air pressure is expressed in pounds per
square inch (psi), or kilopascal (kPa) or
bars.
Aspect ratio
Dimensional relationship between tire
section height and section width
expressed in percentage.Bar
Another metric unit for air pressure. There
are 14.5038 pounds per square inch (psi)
to 1 bar; there are 100 kilopascals (kPa)
to 1 bar.
Bead
The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the
rim.
Cold tire inflation pressure
Tire inflation pressure when your vehicle
has been sitting for at least 3 hours or
driven no more than 1 mile (1.6 km).
Curb weight
The weight of a motor vehicle with stan-
dard equipment including the maximum
capacity of fuel, oil, and coolant, and, if so
equipped, air conditioning and additional
optional equipment, but without passen-
gers and cargo.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

401 Practical hints
Towing the vehicle
Towing the vehicle
Mercedes-Benz recommends that the
vehicle be transported with all wheels off
the ground using flatbed or appropriate
wheel lift/dolly equipment. This method is
preferable to other types of towing.When circumstances do not permit the
recommended towing methods, the
vehicle may be towed with all wheels on
the ground only so far as necessary to have
the vehicle moved to a safe location where
the recommended towing methods can be
employed.
!Use flatbed or wheel lift/dolly equipment,
with SmartKey in starter switch turned to
position0.
Do not tow with sling-type equipment. Towing
with sling-type equipment over bumpy roads will
damage radiator and supports.
To prevent damage during transport, do not tie
down vehicle by its chassis or suspension parts.
Use the towing eyes.
Switch off the ESP
® (page 94), the tow-away
alarm (
page 98) and the automatic central
locking (
page 155).
!Do not tow-start the vehicle.
!When towing the vehicle with all wheels on
the ground, the gear selector lever must be in
neutral positionN and the SmartKey must be in
starter switch position2.
When towing the vehicle with all wheels on the
ground, the vehicle may be towed only for
distances up to 30 miles (50 km) and at a speed
not to exceed 30 mph (50 km/h).
If the vehicle is towed with one axle raised
(observe instructions regarding flexible drive
shaft and propeller shafts), the engine must be
shut off and the SmartKey must be in starter
switch position1. Otherwise, the 4-ETS may
become engaged which may cause loss of
towing control.
Warning!G
If circumstances require towing the vehicle
with all wheels on the ground, always tow
with a tow bar if:

the engine will not run

there is a malfunction in the brake sys-
tem

there is a malfunction in the power
supply or in the vehicle’s electrical
system
This is necessary to adequately control the
towed vehicle.
Prior to towing the vehicle with all wheels on
the ground, make sure the SmartKey is in
starter switch position2.
If the SmartKey is left in the starter switch
position0 for an extended period of time, it
can no longer be turned in the switch. In this
case, the steering is locked. To unlock,
remove SmartKey from starter switch and
reinsert.

402 Practical hints
Towing the vehicle
Warning!G
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the
vehicle. Adapt your driving accordingly.
!Towing of the vehicle should only be done
using the towing eye. Never attach tow cable,
tow rope or tow rod to vehicle chassis, frame or
suspension parts.
iWhen towing the vehicle with all wheels on
the ground, note the following:
With the automatic central locking activated and
the SmartKey in starter switch position2, the
vehicle doors lock if a wheel is turning at vehicle
speeds of approximately 9 mph (15 km/h) or
above.
To prevent the vehicle doors from locking,
deactivate the automatic central locking
(
page 155).
iTo signal turns while being towed with
hazard warning flasher in use, turn the SmartKey
in starter switch to position2 and activate
combination switch for left or right turn signal in
usual manner – only the selected turn signal will
operate.
Upon canceling the turn signal, the hazard
warning flasher will operate again.
iThe gear selector lever will remain locked in
park positionP and the SmartKey will not turn in
the starter switch if the battery is disconnected
or discharged. For more information, see “Bat-
tery” (
page 396) and “Jump starting”
(
page 399).
For information on manually unlocking the gear
selector lever, see (
page 373).

414 Technical data
Layout of poly-V-belt drive
For dimensions of the poly-V-belt, see
technical data (
page 415).
G500
1Automatic belt tensioner
2Power steering pump
3Air conditioning compressor
4Crankshaft
5Coolant pump
6Generator (alternator)
7Idler pulleyG55AMG
The G 55 AMG has two poly-V-belts
(belt one shown in purple/belt two shown
in black).
1Idler pulley
2Automatic belt tensioner
3Power steering pump
4Air conditioning compressor
5Crankshaft
6Coolant pump
7Generator (alternator)
8Idler pulley
9Automatic belt tensioner
aSupercharger

423 Technical data
Fuels, coolants, lubricants, etc.
ModelCapacityFuels, coolants, lubricants, etc.
Engine with oil filterG 500
G55AMG8.5 US qt (8.0 l)
9.0 US qt (8.5 l)Approved engine oils
Automatic transmission9.0 US qt (8.5 l)MB Automatic Transmission Fluid
Transfer case2.96 US qt (2.8 l)MB part no. A 001 989 28 03 10
Differential lock mechanism0.47 - 0.63 US qt (0.45 - 0.6 l)Brake fluid DOT 3+4, SAE J 1703
Front axleG 500
G55AMG1.5 US qt (1.4 l)
1.5 US qt (1.4 l)Hypoid gear oil SAE 85W-90
Hypoid gear oil Castrol SAF-XJ
Rear axleG 500
G55AMG1.9 US qt (1.8 l)
1.9 US qt (1.8 l)Hypoid gear oil SAE 85W-90
Hypoid gear oil Castrol SAF-XJ
Power steeringapprox. 1.06 US qt (1.0 l)MB Power Steering Fluid, or
approved Dexron III ATF
Front wheel hubsapprox. 1.5oz (43g) eachHigh temperature roller bearing grease
Brake system0.86 US qt (0.81 l)MB Brake Fluid (DOT 4+)