2008 MERCEDES-BENZ GL550 torque

205 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.
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299 Controls in detail
Loading
Place rear crossbar7 on roof railsa
in such a way that the clamping claws
reach into gaps8 (
page 298) on the
roof rails.
Make sure clamping claw5 lies flush
against the inside of roof raila as
shown in the illustration (
page 298).
If necessary, adjust clamping width of
crossbars (
page 299).
Slightly tighten screw4 on both sides
by turning it clockwise.
On the front and rear crossbars tighten
screws4. Observe a tightening
torque of 4 lb-ft (6 Nm).
Attach cover caps (page 298) and
lock them.
Store key and Allen wrench back into
the storage well (
page 490).
Adjusting the clamping widths of the
crossbarsThe clamping widths of the crossbars are
factory set for your vehicle. These clamp-
ing widths are solely intended for the des-
ignated positions.
Only install the crossbars at the designat-
ed locations and pay attention to the
stickers3 FRONT and REAR
(
page 298).
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 crossbars. The screws could
come loose if they are not tightened to a
torque of 4 lb-ft (6 Nm).
Warning!G
Only install the crossbars at the exact loca-
tions designated on the roof rails. The desig-
nated locations for the front crossbars are
between the markings engraved on the in-
side of the roof rails (
page 298). The des-
ignated locations for the rear crossbars are
between the gaps on the roof rails
(
page 298).
Otherwise, the crossbars (
page 298),
mounted accessories and the objects at-
tached to them could come loose from the
vehicle causing an accident, thereby injuring
you and other persons and/or causing dam-
age to property, including damage to your
vehicle.

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300 Controls in detail
Loading
Pull cover stripc out of groove until
you see screwsb on each end of the
crossbar.
Turn screwsb on both sides counter-
clockwise approximately 2 rotations.
Place the crossbar at designated loca-
tions (
page 298) 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 crossbar.
Install the crossbars as described
(
page 298).
Removing the crossbars
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 crossbars
can be lifted from the roof rails.
Shortening the cover strip
The cover strips reduce the wind noise
caused by the crossbars. In order to install
add-on roof equipment, it may be neces-
sary to shorten the cover strips.
cCover strip
Pull cover stripc out of groove.
Warning!G
Have the tightening torque checked after
mounting the crossbars. The screws could
come loose if they are not tightened to a
torque of 4 lb-ft (6 Nm).

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359 Operation
Driving instructions

Shift automatic transmission to
position1 (
page 197).

Drive slowly.

Avoid excessive engine speeds – drive
with moderate engine speeds
(max. 3 000 rpm).

Utilize the engine’s braking power
when descending a slope, observe the
engine speed (do not overrev the en-
gine). Apply the service brake as need-
ed.

Check the brakes after a lengthy down-
grade drive.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 hill
iFor maximum engine speed, see “Instru-
ment cluster” (
page 26) and see “Engine”
(
page 553).
Warning!G
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.
iThe hill start assist system supports you
when driving uphill.
For more information, see “Hill start assist sys-
tem” (
page 196).
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.
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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 387).
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 490) and
(
page 519).
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.
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526 Practical hints
Flat tire
Lowering the vehicle
Vehicles with scissors-type jack:
Attach ratchet to vehicle jack in such a
way that the wordDOWN can be seen.
Lower the vehicle until its resting fully
on its own weight.
Vehicles with screw-type jack:
Turn crank counterclockwise.
Vehicles with scissors-type jack:
Turn ratchet in Direction of DOWN.
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.
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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 displacement182 cu in (2987 cm3)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-belt2 035 mm2 404 mm
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554 Technical data
Engine
ModelGL 550 (164.8861)
1All data preliminary. The 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.
Engine273
Mode of operation4-stroke engine, gasoline injection
No. of cylinders8
Bore3.86 in (98.00 mm)
Stroke3.56 in (90.50 mm)
Total piston displacement333.2 cu in (5461 cm3)
Compression ratio10.7:1
Output acc. to SAE J 1349382 hp/6000 rpm2
(285 kW/6000 rpm)
2Premium fuel required. Performance may vary with fuel octane rating.
Maximum torque acc. to SAE J 1349391 lb-ft/2800 - 4800 rpm
(530 Nm/2800 - 4800 rpm)
Maximum engine speed6500 rpm
Firing order1-5-4-2-6-3-7-8
Poly-V-belt2404 mm
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