For more information on engine oil, see
“Fuels, coolants, lubricants etc.”
(Y page 368).
For information on messages in the
multifunction display concerning engine oil,
see the “Practical hints” section
(Y page 308).
Adding engine oil
! Only use approved engine oils and oil
filters required for vehicles with
Maintenance System. For a listing of
approved engine oils and oil filters, contact
an authorized Mercedes-Benz Center or
visit www.mbusa.com (USA only).
The following will result in engine or
emission control system damage not
covered by the Mercedes-Benz Limited
Warranty:
RUsing engine oils and oil filters of
specification other than those expressly
required for the Maintenance System.
RChanging of oil and oil filter at change
intervals longer than those called for by
the Maintenance System.
RUsing any oil additives.
Example illustration: GL 450 (GL 350 BlueTEC,GL 550 similar)
XUnscrew filler cap : from filler neck.XAdd engine oil as required. Be careful not
to overfill with oil.
Be careful not to spill any oil when adding.
Avoid environmental damage caused by oil
entering the ground or water.
! Excess oil must be siphoned or drained
off. It could cause damage to the engine
and emission control system not covered
by the Mercedes-Benz Limited Warranty.
XScrew filler cap : back on filler neck.
For more information on engine oil, see the
“Technical data” section (Y page 368) and
(Y page 370).
Transmission fluid level
The transmission fluid level does not need to
be checked. If you notice transmission fluid
loss or gearshifting malfunctions, have an
authorized Mercedes-Benz Center check the
transmission.
Coolant level
The engine coolant is a mixture of water and
anticorrosion/antifreeze.
When checking the coolant level, the vehicle
must be parked on level ground, and the
coolant temperature must be below 158‡
(70†).
GWarning!
In order to avoid any potentially serious burns:
RUse extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system, or
if the coolant temperature display indicates
that the coolant is overheated.
RDo not remove the cap on the coolant
expansion tank if the coolant temperature
is above 158‡ (70†). Allow the engine to
cool down before removing the cap. The
coolant expansion tank contains hot fluid
and is under pressure.
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After installing winter tires:XCheck the tire inflation pressure and adjust
it if necessary ( Y page 237).XRestart the tire pressure loss warning
system ( Y page 237) or the Advanced Tire
Pressure Monitoring System (Y page 239).
Snow chains
! Vehicles with Adaptive Damping System
(ADS):
When driving with snow chains, do not
select SPORT mode as this may result in
damage to your vehicle.
! Some tire sizes do not leave adequate
clearance for snow chains. To help avoid
serious damage to your vehicle or tires,
make sure the use of snow chains is
permissible as specified in the “Technical
data” section of this Operator’s Manual.
Snow chains should only be driven on snow-
covered roads at speeds not to exceed
30 mph (50 km/h). Remove chains as soon
as possible when driving on roads without
snow.
Observe the following guidelines when using
snow chains:
R Use of snow chains is not permissible with
all wheel/tire combinations ( Y page 365).
R Use snow chains in pairs and on rear
wheels only. Follow the manufacturer’s
mounting instructions.
! If snow chains are mounted to the front
wheels, they may scrape against the body
or axle components. The tires or the vehicle
could be damaged as a result.
R Only use snow chains that are approved by
Mercedes-Benz. Any authorized Mercedes-
Benz Center will be glad to advise you on
this subject.
R Use of snow chains may be prohibited
depending on location. Always check local
and state laws before installing snow
chains.
R Do not use snow chains on the spare wheel.
i When driving with snow chains, you may
wish to switch off the ESP ®
(Y page 63)
before setting the vehicle in motion. This
will improve the vehicle’s traction.
Winter driving instructions
GWarning!
If the vehicle becomes stuck in snow, make
sure snow is kept clear of the exhaust pipe
and from around the vehicle with the engine
running. Otherwise, deadly carbon monoxide
(CO) gases may enter vehicle interior
resulting in unconsciousness and death.
To assure sufficient fresh air ventilation, open
a window slightly on the side of the vehicle
not facing the wind.
GWarning!
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Indicated temperatures just above the
freezing point do not guarantee that the road
surface is free of ice. The road may still be icy,
especially in wooded areas or on bridges.
GWarning!
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle’s ABS will not prevent
this type of control loss.
Do not engage the transfer case in position
LOW when driving on ice or packed snow. At
speeds below 18 mph (30 km/h) vehicle
steering is adversely affected by the Off-road
ABS.
The most important rule for slippery or icy
roads is to drive sensibly and to avoid abrupt
acceleration, braking and steering
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Have the brake system inspected
immediately. Contact an authorized
Mercedes-Benz Center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
Mercedes-Benz Center.
Only install brake pads and use brake fluid
recommended by Mercedes-Benz.GWarning!
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that safe
braking is substantially impaired. This could
result in an accident.
! Only conduct operational or performance
tests on a two-axle dynamometer. If such
tests are necessary, contact an authorized
Mercedes-Benz 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
position 0 or 1 or KEYLESS-GO start/stop
button in position 0 or 1) when the parking
brake is being tested on a brake test
dynamometer. 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.
If your brake system is 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.
GWarning!
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.
Refer to the description of the Brake Assist
System (BAS) ( Y page 63).
Parking brake
When driving on wet roads or dirt covered
surfaces, road salt and/or dirt can get into
the parking brake.
To prevent corrosion and a reduction in the
braking power of the parking brake, observe
the following:
XFrom time to time, lightly engage the
parking brake before driving off.XDrive a distance of approximately 110 yds
(100 m) at a maximum speed of 12 mph
(20 km/h).GWarning!
While performing this procedure please
assure that the vehicle is stopped before
applying the parking brake. Otherwise the
rear wheels could lock up. You could lose
control of the vehicle and cause an accident.
In addition, the vehicle’s brake lights do not
light up when the parking brake is engaged.
Make sure not to endanger any other road
users when you engage the parking brake.
Driving off
Warm up the engine smoothly. Do not place
full load on the engine until the operating
temperature has been reached.
! When driving off on a slippery surface, do
not allow a drive wheel to spin for an
extended period with the ESP ®
switched
off. Doing so may cause serious damage to
the drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
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! Simultaneously depressing the
accelerator pedal and applying the brakes
reduces engine performance and causes
premature brake and drivetrain wear which
is not covered by the Mercedes-Benz
Limited Warranty.
Hydroplaning
Depending on the depth of the water layer on
the road, hydroplaning may occur, even at low
speeds and with new tires. In heavy rain or
when conditions indicate possible
hydroplaning:
XReduce vehicle speed.XAvoid track grooves in the road.XApply brakes cautiously.
Standing water
! Do not drive through flooded areas.
Before driving through water, determine its
depth.
If you must drive through standing water,
drive slowly to prevent water from entering
the passenger compartment or the engine
compartment. Water in these areas could
cause damage to electrical components or
wiring of the engine or transmission, or
could result in water being ingested by the
engine through the air intake causing
severe internal engine damage. Any such
damage is not covered by the Mercedes-
Benz Limited Warranty.
i Select the raised level ( Y page 159)
before driving through standing water.
For more information, see “Driving through
water” ( Y page 266).
Off-road drivingGWarning!
Do not load items on the crossbars. It may
cause instability during some maneuvers
which could result in an accident.
Drive slowly in unknown terrain. This will
make it easier to recognize unexpected
obstacles and avoid damage to the vehicle.
To help avoid the vehicle rolling over, never
turn it around on steep inclines. If the vehicle
cannot complete the attempted climb, back it
down in reverse gear.
Do not drive along the side of a slope. The
vehicle might otherwise rollover. If in doing so
the vehicle begins to show a tendency to roll,
immediately steer into a line of gravity
(straight up or downhill).
Never let the vehicle roll backwards in idle.
You may lose control of the vehicle if you use
only the service brake. For information on
driving downhill, see “Driving downhill”.
GWarning!
Sand, dirt, mud and other material having
friction property can cause exceptional wear
and tear as well as brake failure.
Have the brakes checked for dirt build-up and
cleaned. There is otherwise a risk that full
braking power may not be available in an
emergency.
GWarning!
Please be aware that by raising the vehicle
level, the center of gravity also rises.
Therefore, always ensure that the vehicle
level is as low as possible. With higher ride
height the ESP ®
may activate earlier in certain
situations.
Read this chapter carefully before you begin
off-road travel.
Familiarize yourself with the vehicle
characteristics and gear changing before you
attempt any difficult terrain off-road driving.
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Checklist before off-road driving
Engine oil level
RCheck the engine oil level (Y page 230).
Only with a proper oil level can the vehicle
obtain a trouble-free oil supply, even on
steep gradients.
! If the engine oil level warning lamp comes
on while driving, stop the vehicle in a safe
location or as soon at is safe to do so.
Check the engine oil level.
The engine oil level warnings should not be
ignored. Extended driving with the symbol
displayed could result in serious engine
damage that is not covered by the
Mercedes-Benz Limited Warranty.
Tires
RCheck the tread depth and maintain
specified tire inflation pressure. A placard
with the recommended tire inflation
pressures is located on the driver’s door B-
pillar (Y page 243).
RCheck tires for possible damage and
remove foreign objects.
RReplace missing valve caps.
Rims
RDented or bent rims can cause tire inflation
pressure loss and damage the tire beads.
For this reason, check and, if necessary,
change rims before driving off-road.
Vehicle tool kit
RCheck if the jack (Y page 286) is
functional.
RAlways take the vehicle tool kit, a strong
tow rope, a shovel and a small plank (to put
under the jack on sandy soil) with you.
Driving in steep terrain
Slope angle
:Overhang angle, front;Overhang angle, rearVehicles
with air
suspension
program
:
GL 450,
GL 350
BlueTEC
:
GL
550
;
all
models
Raised level31°32°26°Highway26°27°21°Vehicles
with
enhanced
off-road
package
:
GL 450,
GL 350
BlueTEC
:
GL
550
;
all
models
Off-road
level 3
32°33°27°Off-road
level 2
31°32°26°Off-road
level 1
28°28°23°Highway26°27°21°
RComply with the warnings (Y page 262) and
rules for off-road driving (Y page 263).
RDriving on embankments, slopes and other
steep inclines should only be done straight
up or downhill, i.e. in the line of gravity.
Maximum vehicle climbing ability is a
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100% grade which is equivalent to a slope
angle of 45°. Keep in mind that the
climbing ability of the vehicle depends on
terrain conditions.
R Shift automatic transmission into gear
range 1 (Y page 118).
R Drive slowly.
R Avoid excessive engine speeds – drive with
moderate engine speeds (max. 3 000 rpm).
R Utilize the engine’s braking power when
descending a slope, observe the engine
speed (do not overrev the engine). Apply
the service brake as needed.
i For maximum engine speed, see
“Tachometer” (Y page 125) and see vehicle
specification for your vehicle
( Y page 362).
R Check the brakes after a lengthy
downgrade drive.GWarning!
Never turn the vehicle around on steep
inclines. The vehicle might roll over. If the
vehicle cannot complete the attempted climb,
back it down in reverse gear.
i The hill-start assist system supports you
when driving uphill.
For more information, see “Hill-start assist
system” ( Y page 155).
Traction in steep terrain
The maximum vehicle climbing ability is a
100% grade which is equivalent to a slope
angle of 45°. Keep in mind that the climbing
ability of the vehicle depends on terrain
conditions.
Be easy on the accelerator and watch for
continuous wheel traction when driving in
steep terrain.
i The 4-ETS helps greatly when starting out
on a steep incline when the front wheels
have then the tendency to slip due to the
weight shifting towards the rear axle.
The 4-ETS recognizes the situation and
limits the torque for the front wheels by
braking them.
Simultaneously the torque for the rear
wheels is increased.
i Vehicles with enhanced off-road package
are equipped with automatic locks for the
center and rear axle differential to improve
vehicle traction.
Driving across a hilltop
Decelerate just ahead of a hilltop (do not shift
automatic transmission into neutral position
N ), to prevent the vehicle from speeding up
too much after climbing a hill.
Use the momentum of the vehicle to drive
across the hilltop.
After climbing a hill, driving in this manner
prevents the vehicle from:
R losing ground contact when cresting hills
R losing its forward momentum
R speeding up too much after climbing the hill
Driving downhill
R Drive slowly.
R Do not drive at an angle to the incline. Steer
into the line of gravity and drive with the
front wheels pointing straight downhill.
Otherwise, the vehicle may slide sideways
off the path and roll over.
R Shift automatic transmission into gear
range 1 (Y page 118).
R On steep inclines, use the Downhill Speed
Regulation ( Y page 155).
R Utilize the engine’s braking power to
reduce vehicle speed.
If this is insufficient, apply the brakes
gently. Make sure the vehicle is moving in
the line of gravity.
R Check the brakes after a lengthy
downgrade drive.
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Crossing obstacles
! Obstacles can damage the vehicle
underbody or suspension components. If
possible use the assistance of a second
person outside the vehicle to scout the
path you intend to take and check for
adequate ground clearance when you cross
obstacles with your vehicle. The person
assisting you outside the vehicle should
always be a safe distance away from the
vehicle and positioned so that he or she
cannot get hurt in case of any unexpected
vehicle movement.
After off-road driving or crossing obstacles,
inspect vehicle for any damage, especially
vehicle underbody and suspension
components. Failure to do so can adversely
affect the vehicle’s future performance,
including increased chance of an accident.
When driving over tree stumps, big rocks and
other obstacles, observe the following rules:
RMake sure the off-road driving program
(Y page 158) or if equipped the
LOW RANGE mode (Y page 120) is
switched on.
RAvoid high engine speeds.
RShift automatic transmission into gear
range 1 (Y page 118).
RCheck the vehicle clearance before
crossing obstacles.
RCross obstacles (e.g. tree stumps or big
rocks) very slowly by aiming one of the front
wheels at the center of the obstacle, and
repeat same with the rear wheel.
! Special attention is needed when you
cross obstacles on a steep incline.
The vehicle could slide sideways as a result
of its possible slanted position which in turn
may result in the vehicle tipping or rolling
over.
Driving on sand
GWarning!
Do not reduce the tire inflation pressure
before driving through sand. However, if you
do so, remember to correct the tire inflation
pressure before continuing your trip. Driving
with reduced tire inflation pressure increases
the risk of losing control of the vehicle and
rolling over.
When driving on sand, observe the following
rules:RSet the raised level (Y page 159).
RAvoid high engine speeds.
RShift automatic transmission into a gear
range that is appropriate for the terrain.
RIn sandy soil, drive at a steady speed as
conditions permit. This helps overcome the
vehicle rolling resistance and reduce the
likelihood of the vehicle sinking into the
ground.
RDrive in tracks of other vehicles if they are
not too deep and you have sufficient
clearance.
Ruts
A number of off-road tracks or other byways
have deep ruts which can cause the
underbody to come in contact with the
ground.
RMake sure the off-road driving program
(Y page 158) or, if equipped, the
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LOW RANGE mode (Y page 120) is
switched on.
R Set the raised level ( Y page 159).
! Check that the ruts are not too deep and
your vehicle’s clearance is sufficient.
Otherwise:
R your vehicle may be damaged
R the underbody of the vehicle may come
in contact with the ground and you may
get stuck
R Avoid high engine speeds.
R Shift automatic transmission into gear
range 1 (Y page 118).
R Drive next to the ruts rather than through
them if at all possible.
R If the ruts are too deep to drive in, drive with
one side of the vehicle on the grassy center
strip if the route permits.
Returning from off-road driving GWarning!
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possible
damage to your vehicle has occurred, you
should turn on the hazard warning flashers,
carefully slow down, and drive with caution to
an area which is a safe distance from the road.
Inspect the tires and the vehicle underbody
for possible damage. If the vehicle or tires
appear unsafe, have the vehicle towed to the
nearest authorized Mercedes-Benz Center or
tire dealer for repairs.
Off-road driving increases strain on the
vehicle.
We recommend that you inspect the vehicle
for possible damage after each off-road trip.
Recognizing any damage and a subsequent
timely repair reduces the chance of a possible
breakdown or accident later on.
Proceed as follows:
R Switch off the off-road driving program
( Y page 158) or the LOW RANGE mode
( Y page 120).
R Switch off the DSR ( Y page 156).
R Set the differential locks to AUTO
( Y page 122).
R Lower the vehicle back to a level suitable
for road conditions, e.g. highway/high-
speed level ( Y page 159).
R Clean all exterior lamps and check for
possible damage.
R Clean the front and rear license plate.
R Remove excessive dirt from tires, wheels,
wheel housings, and underbody.
For instance, after driving in mud, clean the
radiator, chassis, engine, brakes, and
wheels from extreme dirt using a strong jet
of water.
R Check tires for possible damage.
R Inspect vehicle underbody, oil pan, brake
hoses, etc., as well as vehicle underbody
for possible damage.
R Check for brush or branches caught in the
underbody.
! Brush or branches could increase the
possibility of a fire, as well as cut fuel and/
or brake lines, puncture rubber bellows of
the axles or drive shafts.
R After continued operation in mud, sand,
water or other dirty conditions clean the
brake discs, wheels, brake pads and check
and clean axle joints.
R Conduct a brake test.268Driving instructionsOperation
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