2007 MERCEDES-BENZ GL450 differential

209 Controls in detail
Differential locks*
Start the engine (page 42).
To select the required locking mode,
rotate adjustment ring2 to the
desired position3 or4
(
page 207).
The indicator lamp on the adjustment
ring1 at the respective symbol
comes on.
Example
5Center differential is completely locked
!If the differential locks have been manually
engaged, the tires will scuff on the road surface
when cornering because the differences be-
tween the individual wheel rotation speeds will
not be compensated for.
iThe differential locks are reset to AUTO
mode after the ignition has been switched off for
longer than 10 seconds.

348 Operation
In the “Operation” section you will find
detailed information on operating, main-
taining and caring for your vehicle.
The first 1000 miles (1500 km)
The more cautiously you treat your vehicle
during the break-in period, the more satis-
fied you will be with its performance later
on.

Drive your vehicle during the first
1000 miles (1500 km) at varying but
moderate vehicle and engine speeds.

During this period, avoid heavy loads
(full throttle driving) and excessive
engine speeds (no more than
2/3 of
maximum rpm in each gear).

Shift gears in a timely manner.

Avoid accelerating by kick-down.

Do not attempt to slow the vehicle
down by shifting to a lower gear using
the gear selector lever.

Select gear ranges3, 2 or1
(
page 200) only when driving at
moderate speeds (for hill driving).After 1000 miles (1500 km) you may
gradually increase vehicle and engine
speeds to the permissible maximum.
All of the above instructions, as may apply
to your vehicle type, also apply when driv-
ing the first 1000 miles (1500 km) after
the engine, the transfer case, the center
differential or the rear differential has been
replaced.
iAlways obey applicable speed limits.

358 Operation
Driving instructions
Special driving features for off-road
driving
The following driving features are available
for specific kind of operation:

Off-road – ABS (page 104)

Off-road – ESP® (page 108)

Off-road – 4-ETS (page 110)

Hill start assist system (page 199)

LOW RANGE mode* (page 203)

Differential locks* (page 206)

Downhill Speed Regulation (DSR)
(
page 275)

Off-road driving program (Vehicles
without enhanced off-road package*)
(
page 279)

Air suspension (page 280)Off-road driving rules

Engage the off-road driving program
(
page 279) or LOW RANGE mode*
(
page 203) before driving under
off-road conditions.

If necessary, activate differential
locks* (
page 206).

Make sure you select a vehicle level
(
page 281) appropriate to the topo-
graphical conditions. Always make
sure the vehicle has enough ground
clearance.

Fasten items being carried as securely
as possible (
page 297).

Always navigate gradients with the en-
gine on and with the transmission en-
gaged in a gear. Switch on the DSR
(
page 276) to help maintain a preset
speed.
!Observe the following during off-road
driving:

Keep doors, tailgate, windows, and
tilt/sliding sunroof* closed whenever driving
off-road.

Adjust vehicle speed to condition of terrain.
The more uneven, rutty and steeper the ter-
rain, the lower the speed should be. Drive
through water slowly at an even speed,
avoiding a bow wave.

Be especially careful when driving in un-
known territory. It may be necessary to get
out of the vehicle and scout the path you in-
tend to take.

Watch out for obstacles, such as rocks,
holes, tree stumps and ruts.

Before driving through water, determine its
depth.

Do not stop vehicle while immersed in water,
and do not shut off the engine.

361 Operation
Driving instructions
Traction in steep terrain
The maximum vehicle climbing ability is a
100% grade which is equivalent to a slope
angle of 45 degrees. 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.Driving across a hilltop
Decelerate just ahead of a hilltop (do not
shift automatic transmission to
positionN), 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:

losing ground contact when cresting
hills

losing its forward momentum

speeding up too much after climbing
the hillDriving downhill

Drive slowly.

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.

Shift automatic transmission to
position1 (
page 200).

On steep inclines, use the Downhill
Speed Regulation (
page 275).

Utilize the engine’s braking power to
reduce vehicle speed.
If this is insufficient, apply the brake
gently. Make sure the vehicle is moving
in the line of gravity.

Check the brakes after a lengthy down-
grade drive.
iThe hill start assist system supports you
when driving uphill.
For more information, see “Hill start assist sys-
tem” (
page 199).
iThe 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.
iVehicles with enhanced off-road package*
are equipped with automatic locks for the center
and rear axle differential to improve vehicle
traction.

365 Operation
Driving instructions
Returning from off-road drivingOff-road driving increases strain on the
vehicle.
We recommend that you inspect the vehi-
cle for possible damage after each off-road
trip. Recognizing any damage and a subse-
quent timely repair reduces the chance of
a possible breakdown or accident later on.
Proceed as follows:

Switch off the off-road driving program
(
page 280) or the LOW RANGE
mode* (
page 203).

Switch off the DSR (page 276).

Set the differential locks* to AUTO
(
page 207).

Lower the vehicle back to a level
suitable for road conditions, e.g. High-
way/High-speed level (
page 281).

Clean all exterior lamps and check for
possible damage.

Clean the front and rear license plate.

Remove excessive dirt from tires,
wheels, wheel housings, and under-
body.
For instance, after driving in mud, clean
the radiator, chassis, engine, brakes,
and wheels from extreme dirt using a
strong jet of water.

Check tires for possible damage.

Inspect vehicle underbody, oil pan,
brake hoses, etc., as well as vehicle un-
derbody for possible damage.

Check for brush or branches caught in
the underbody.

After continued operation in mud,
sand, water or other dirty conditions
clean the brake discs, wheels, brake
pads and check and clean axle joints.

Conduct a brake test.
Warning!G
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possi-
ble damage to your vehicle has occurred,
you should turn on the hazard warning flash-
ers, carefully slow down, and drive with cau-
tion to an area which is a safe distance from
the roadway.
Inspect the tires and under the vehicle for
possible damage. If the vehicle or tires ap-
pear unsafe, have it towed to the nearest
Mercedes-Benz Light Truck Center or tire
dealer for repairs.
Damage to the vehicle may influence driving
comfort and pose the risk of accident to you
and other drivers.
!Brush or branches could increase the possi-
bility of a fire, as well as cut fuel and/or brake
lines, puncture rubber bellows of the axles or
drive shafts.

493 Practical hints
What to do if …
Display symbolDisplay messagesPossible cause/consequencePossible solution
kDiff. lock system malfunct.
Visit workshopThe differential locks* are
malfunctioning.Do not drive faster than 50 mph
(80 km/h).
Have the vehicle checked at an autho-
rized Mercedes-Benz Light Truck
Center.
Diff. Lock System
overheated. Wait briefly.The differential locks* are too hot
and have been deactivated as a re-
sult.Continue driving with added caution.
The lock function is unavailable.
Wait for the lock system to cool down.
The differential locks will be reactivat-
ed as soon as they have cooled off.
mStop vehicle
Engage parking brakeA shifting procedure could not be
completed. LOW RANGE* is in neu-
tral position. There is no connection
between the engine and the drive
wheels.Do not attempt to continue driving.
You could otherwise damage the
vehicle’s drivetrain.
Let the vehicle coast to a halt.
 Engage the parking brake.
Perform the shifting procedure again
(
page 204).

560 Technical data
Fuels, coolants, lubricants
Capacities
Vehicle components and their respective
lubricants must match. Therefore only use
products tested and approved by
Mercerdes-Benz.
Please refer to the Factory Approved
Service Products pamphlet (USA only), or
inquire at an authorized Mercedes-Benz
Light Truck Center.
Warning!G
Comply with all valid regulations with re-
spect to handling, storing and disposing of
service fluids. Otherwise you could
endanger persons or the environment.
Keep service fluids out of the reach of
children.
For health reasons, you should prevent
service fluids from coming into direct
contact with your skin or clothing.
If a service fluid is swallowed, contact a
physician immediately.
ModelCapacityFuels, coolants, lubricants, etc.
Engine with oil filterAll models9.0 US qt (8.5 l)Approved engine oils
Automatic transmissionAll models9.5 US qt (9.0 l)MB Automatic Transmission Fluid
Transfer case single speedAll models0.5 US qt (0.5 l)MB Automatic Transmission Fluid
Transfer case double speed*All models1.6 US qt (1.5 l)MB Automatic Transmission Fluid
Front axleAll models1.2 US qt (1.1 l)Hypoid gear oil
Rear axleAll models1.2 US qt (1.1 l)Hypoid gear oil
Rear axle with differential lock*All models1.7 US qt (1.6 l)Hypoid gear oil

573 Index
Corner-illuminating front fog lamps* 150
Messages in the
multifunction display 481
Replacing bulbs 514
Crossing obstacles 363
Cruise control 257
Activating 259
Messages in the
multifunction display 454
Cup holders 321
Cleaning 322
Front center console 322
Front center console,
Removing/Installing 322
Rear armrest 321
Curb weight 416
D
Date display, Setting 176, 177
Daytime running lamp mode 147
Setting 178
Deep water see Standing water
Defogging windshield 223, 237
Defrosting, Front 223, 237
Defrosting, Rear 215Delayed shut-off
Exterior lamps 179
Interior lighting 180
Department of Transportation see DOT
Diesel engine
Preglow indicator lamp 29
Differential locks* 206
A few words about 206
Messages in the
multifunction display 493
Switching 207
Difficulties
While driving 66
While starting 60
Digital clock see Clock
Digital speedometer 157, 165
Dimensions, Vehicle 558
Direction of rotation (tires) 388
Displays
Digital speedometer 157, 165
Distronic* 265
Maintenance service indicator 422
Messages in the
multifunction display 451
Multifunction display 157Outside temperature 157, 165
Selecting 175
Symbol messages 469
Text messages 453
Vehicle status message 170, 451
Vehicle system settings, Control
system 161, 163, 170
Distance to empty (range), Trip
Computer 187
Distronic* 262
Activating 268
Cleaning system sensor 430
Control system 266
Deactivating 270
Distance warning function* 274
Distance warning function*
activating/deactivating 186
Driving hints 272
Messages in the
multifunction display 455
Sensor cover 430
Warning and indicator lamps 265