Page 208 of 595

207 Controls in detail
Differential locks*
at the same speed, independent of the in-
dividual torque. Please be aware that en-
gaging 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
®, man-
ual switch position “LOW” of transfer case)
this vehicle comes equipped with.
Switching differential locks*The rotary switch for the differential locks
is located on the upper part of the center
console.
You can select between three locking
modes.
1Rotatable outer adjustment ring with
indicator lamp
2AUTO mode: center differential is auto-
matically locked
3Center differential is completely locked
4Center and rear axle differential are
completely locked
!If the differential locks are engaged, accel-
erate gently when setting the vehicle in motion.
To avoid damage to the transmission, the vehicle
may only be operated on a dynamometer (single
axle dynamometer) if
the axle not being driven is jacked up
or
the associated propeller shaft is disconnect-
ed.
Page 302 of 595

301 Controls in detail
Loading
Place rear basic cross bar7 on roof
railsa i n s u c h a w a y t h a t t h e c l a m p i n g
claws reach into gaps8 (
page 300)
on the roof rails.
Make sure clamping claw5 lies flush
against the inside of roof raila as
shown in the illustration (
page 300).
If necessary, adjust clamping width of
basic cross bars (
page 301).
Slightly tighten screw4 on both sides
by turning it clockwise.
On the front and rear basic cross bars
tighten screws4. Observe a
tightening torque of 4 lb-ft (6 Nm).
Attach cover caps (page 300) and
lock them.
Store key and Allen wrench back into
the storage well (
page 495).
Adjusting the clamping widths of the
basic cross barsThe clamping widths of the basic cross
bars are factory set for your vehicle. These
clamping widths are solely intended for the
designated positions.
Only install the basic cross bars at the des-
ignated locations and pay attention to the
stickers3 FRONT and REAR
(
page 300).
4Screw for clamping claw
5Clamping claw
bScrews for adjusting clamping width
(2 in total for each side)
cCover strip
Warning!G
Have the tightening torque checked after
mounting the basic cross bars. The screws
could come loose if they are not tightened to
a torque of 4 lb-ft (6 Nm).
Warning!G
Only install the basic cross bars at the exact
locations designated on the roof rails. The
designated locations for the front basic
cross bars are between the markings en-
graved on the inside of the roof rails
(
page 300). The designated locations for
the rear basic cross bars are between the
gaps on the roof rails (
page 300).
Otherwise, the basic cross bars
(
page 300), mounted accessories and the
objects attached to them could come loose
from the vehicle causing an accident, there-
by injuring you and other persons and/or
causing damage to property, including dam-
age to your vehicle.
Page 303 of 595

302 Controls in detail
Loading
Pull cover stripc out of groove until
you see screwsb on each end of the
basic cross bar.
Turn screwsb on both sides counter-
clockwise approximately 2 rotations.
Place the basic cross bar at designated
locations (
page 300) on roof rails.
On both sides, make sure the clamping
claws5 lie flush against the roof rails.
If necessary pull out or push in the
clamping claws5.
Tighten screwsb. Observe a
tightening torque of 4 lb-ft (6 Nm).
The width of the clamping claws is
correctly adjusted.
Press cover stripc piece by piece into
groove of basic cross bar.
Install the basic cross bars as
described (
page 300).Removing the basic cross bars
1Key
2Cover cap
3Sticker FRONT (or REAR)
4Screw for clamping claw
5Clamping claw
Unlock cover cap2 with key1.
Remove cover cap2.
Turn screws for clamping claws5
counterclockwise until the basic cross
bars can be lifted from the roof rails.Shortening the cover strip
The cover strips reduce the wind noise
caused by the basic cross bars. In order to
install add-on roof equipment, it may be
necessary to shorten the cover strips.
cCover strip
Pull cover stripc out of groove.
Page 362 of 595

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.
Page 420 of 595

419 Operation
Tires and wheels
In some cases, such as when your vehicle
is equipped with mixed-size tires (different
tire dimension front vs. rear), tire rotation
is not possible.
If applicable to your vehicle’s tire configu-
ration, tires can be rotated according to
the tire manufacturer’s recommended in-
tervals in the tire manufacturer’s warranty
pamphlet located in your vehicle literature
portfolio. If none is available, tires should
be rotated every 3 000 to 6 000 miles
(5 000 to 10 000 km), or sooner if neces-
sary, according to the degree of tire wear.
The same rotation (spinning) direction
must be maintained (
page 388).
Rotate tires before the characteristic tire
wear pattern becomes visible (shoulder
wear on front tires and tread center wear
on rear tires).
Thoroughly clean the mounting face of
wheels and brake disks, i.e. the inner side
of the wheels/tires, during each rotation.
Check for and ensure proper tire inflation
pressure.For information on wheel change, see the
“Practical hints” section (
page 495) and
(
page 523).
Warning!G
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
110 lb-ft (150 Nm).
Only use genuine Mercedes-Benz wheel
bolts specified for your vehicle’s rims.
Page 529 of 595
528 Practical hints
Flat tire
Lowering the vehicle
Lower vehicle by turning crank coun-
terclockwise until vehicle is resting ful-
ly on its own weight.
Remove the jack.
1-5Wheel bolts
Tighten the five wheel bolts evenly, fol-
lowing the diagonal sequence illustrat-
ed (1 to 5), until all bolts are tight.
Observe a tightening torque of
110 lb-ft (150 Nm).
Store jack and all other vehicle tool kit
items back into the storage well.
Warning!G
Have the tightening torque checked after
changing a wheel. The wheels could come
loose if they are not tightened to a torque of
110 lb-ft (150 Nm).
iThe removed road wheel cannot be stored in
the spare wheel well under the cargo compart-
ment floor, but should be transported in the car-
go compartment wrapped in a protective cover.
Vehicles with TPMS or Advanced TPMS*:
Do not activate the tire inflation pressure moni-
tor until a full size wheel/tire with functioning
sensor has been placed back into service on the
vehicle.
Page 554 of 595
553 Technical data
Engine
Engine
ModelGL 320 CDI (164.8221)
1The quoted data apply only to the standard vehicle. See an authorized Mercedes-Benz Light Truck Center for the corresponding data of all special bodies and special
equipment.
GL 450 (164.8711)
Engine642273
Mode of operationDiesel 4-stroke engine4-stroke engine, gasoline injection
No. of cylinders68
Bore3.27 in (83.00 mm)3.66 in (92.90 mm)
Stroke3.62 in (92.00 mm)3.38 in (86.00 mm)
Total piston displacement182cuin (2987cm3)285 cu in (4663 cm3)
Compression ratio17.7:110.7:1
Output acc. to SAE J 1349215 hp/4000 rpm
(160 kW/4000 rpm)335 hp/6000 rpm2
(250 kW/6000 rpm)
2Premium fuel required. Performance may vary with fuel octane rating.
Maximum torque acc. to SAE J 1349400 lb-ft/1600 - 2400 rpm
(543 Nm/1600 - 2400 rpm)339 lb-ft/2700 - 5000 rpm
(460 Nm/2700 - 5000 rpm)
Maximum engine speed4500 rpm6500 rpm
Firing order1-4-2-5-3-61-5-4-2-6-3-7-8
Poly-V-belt2035 mm2404 mm
Page 558 of 595
557 Technical data
Electrical system
Electrical system
ModelGL 450
Generator (alternator)14 V/180 A
Starter motor12 V/1.7 kW
Battery12 V/95 Ah
Spark plugsNGK PLKR6A
Electrode gap0.031 in (0.8 mm)
Tightening torque15 – 22 lb-ft (20 – 30 Nm)
ModelGL 320 CDI
Generator (alternator)14 V/220 A
Starter motor12 V/2.0 kW
Battery12 V/95 Ah