wheel AUDI A4 2008 B8 / 4.G Service Manual

Intelligent technology 226Applies to vehicles: with four-wheel driveFour-wheel drive (quattro
®)
On quattro models the engine power is distributed to all
four wheelsGeneral notes
On four-wheel drive vehicles, the engine power is distributed to all
four wheels. The distribution of power is controlled automatically
according to your driving style and the road conditions. Also refer
to ⇒page 222, “Description”.
The four-wheel drive is specially designed to complement the supe-
rior engine power of your Audi. This combination gives the car
exceptional handling and performance capabilities – both on
normal roads and in more difficult conditions, such as snow and ice.
Even so (or perhaps especially for this reason), it is important to
observe certain safety points ⇒.
Winter tyres
Thanks to its four-wheel drive, your car will have plenty of traction
in winter conditions, even with the standard tyres. Nevertheless, we
still recommend that winter tyres or all-season tyres should be fitted
on all four wheels when winter road conditions are expected, mainly
because this will give a better braking response.
Snow chains
On roads where snow chains are mandatory, this also applies to cars
with four-wheel drive ⇒page 273, “Snow chains”.
Replacing tyres
On vehicles with four-wheel drive, all four tyres must have the same
rolling circumference. Also avoid using tyres with varying tread
depths ⇒page 270, “Replacing wheels and tyres”.Off-roader?
Your Audi does not have enough ground clearance to be used as an
off-road vehicle. It is therefore best to avoid rough tracks and
uneven terrain as much as possible.
WARNING
•
Even with four-wheel drive, you should always adjust your
speed to suit the conditions. Do not let the extra safety provided
tempt you into taking any risks when driving – this can cause acci-
dents.
•
The braking ability of your car is limited by the grip of the tyres.
In this respect, your car is no different from a car without four-
wheel drive. So do not be tempted to drive too fast on icy or slip-
pery roads just because the car still has good acceleration in these
conditions (accident risk).
•
On wet roads bear in mind that the front wheels may start to
“aquaplane” and lose contact with the road if the car is driven too
fast. If this should happen, there will be no sudden increase in
engine speed to warn the driver, as with a front-wheel drive car. So
do not drive too fast in the wet: adjust your speed to suit the
conditions (accident risk).
Power managementThis system helps to ensure reliable starting
The power management controls the distribution of elec-
trical energy and thus helps to ensure that there is always
enough power available to start the engine.If a vehicle with a conventional electrical system is left parked for a
long time, the battery will gradually lose its charge because certain
electrical equipment (such as the immobiliser) continues to draw
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Towing a trailer233
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data additional mirrors fitted. Both exterior mirrors should be mounted
on hinged extension brackets. Adjust the mirrors to give sufficient
vision to the rear.
Headlights
Before starting a journey, check the headlight beam settings with
the trailer hitched up. If necessary, alter the height of the headlight
beams by means of the headlight range control ⇒page 60.
Power supply
When you remove the ignition key the power supply to the trailer is
interrupted.
Removable ball joint coupling
Vehicles with a factory-fitted towing bracket are equipped with a
removable ball joint coupling. It is carried under the floor panel on
the left-hand side of the luggage compartment and is secured by a
strap.
Note
We recommend having the car serviced between the normal inspec-
tion intervals if it used frequently for towing a trailer.Applies to vehicles: with towing bracketTrailer stabilisation system
Trailer stabilisation helps to reduce the risk of the vehicle
skidding when towing a trailer.The trailer stabilisation system is operational only when the ESP is
switched on and there is no malfunction in the ESP ⇒page 17.
When is the trailer stabilisation system activated?
Trailer stabilisation is active when the following requirements are
met:•
The ESP must NOT be switched off ⇒page 222,
•
The trailer connector must be properly secured in the vehicle
socket.
•
Vehicle speed must be higher than approx. 60 km/h.
How trailer stabilisation works:
In many cases, the driver can stabilise a swaying trailer by manually
braking the vehicle.
However, if the ESP detects that the trailer is swaying and this is
affecting the towing vehicle, it will automatically brake the vehicle
to stabilise the trailer by slowing it down. The warning lamp
 will
light up in the instrument cluster. If possible, do not turn the
steering wheel at this stage.
In order to warn traffic behind you, the brake lights will come on
during this automatic braking operation.
A trailer weighing less than 70% of the kerb weight of the towing
vehicle may sway quite considerably without the trailer stabilisation
system intervening. This can happen when the swaying movements
of the light-weight trailer are not or hardly passed on to the towing
vehicle and are therefore not detected by the ESP.
If the system for activating the trailer brake lights is defective, this
will be indicated in the instrument cluster display ⇒page 37, “Bulb
monitor ”.
Requirements for correct functioning of the trailer
stabilisation system
If these conditions are not met in full, the trailer stabilisation system
will only intervene to a limited extent or not at all ⇒.
•
The electrical connection between the towing vehicle and the
trailer must be functioning correctly, without any defects.
•
The load on the trailer must be properly secured.
•
The tyre pressures on both the vehicle and the trailer must be
adapted to the load that is being carried.
•
Where possible, operate the trailer with the maximum permitted
draw bar weight.
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Towing a trailer 234•
The trailer overrun brake must be set correctly. This is important
to ensure that the trailer can be braked correctly, to avoid the vehicle
and trailer “jack-knifing” and to prevent excess braking of the trailer.
•
At low outside temperatures, both the towing vehicle and the
trailer should be fitted with winter tyres.
WARNING
It is essential that you adjust your speed to suit the weather, road
and traffic conditions. Do not let the trailer stabilisation system
tempt you into taking any risks when driving – this can cause acci-
dents.•
The ESP and trailer stabilisation system cannot defy the laws
of physics. This should be kept in mind, particularly on slippery
and wet roads and when towing a trailer with a light load.
•
The trailer stabilisation system is functional, regardless of
whether the trailer has a mechanical overrun brake or not.
•
The trailer stabilisation system is not always able to detect
swaying of trailers with a light load and will therefore not inter-
vene.
•
A trailer can still “jack-knife” on slippery roads with little grip,
even if the towing vehicle is equipped with the trailer stabilisation
system.
•
Trailers with a high centre of gravity may even tip over before
they start to sway sideways.
•
If you are not towing a trailer, but the trailer socket is being
used (e.g. for an illuminated bicycle rack), the trailer stabilisation
system may be activated in extreme driving conditions.
•
Please note the additional information and warnings
⇒page 234.
Notes on towing
Driving with a trailer always requires extra care.Weight distribution
Try to avoid towing a loaded trailer with an unladen vehicle. If this
cannot be avoided, drive extra slowly to allow for the unbalanced
weight distribution.
Speed
The stability of the car and trailer is reduced with increasing speed.
For this reason it is advisable not to drive at the maximum permis-
sible top speed in unfavourable road, weather or wind conditions.
This applies especially on a downhill gradient.
You should always reduce speed immediately if the trailer shows
the slightest sign of swaying. Never try to stop the swaying by accel-
erating further.
Always brake in good time. If the trailer has an overrun brake, apply
the brakes gently at first and then firmly. This will prevent the jerking
that can be caused by the trailer wheels locking. Change down in
good time before going down a steep hill so that you can use the
engine braking effect to slow down the vehicle.
Swaying and pitching can be reduced by stabiliser aids. We recom-
mend having stabiliser aids installed when towing trailers with a
high trailer weight. They can be purchased and installed at an Audi
dealer.
Overheating
When climbing long hills in hot weather with the engine running
fast in low gear, you should keep an eye on the coolant temperature
gauge ⇒page 11. Reduce speed immediately if the needle moves to
the top end of the scale. If the temperature warning lamp
 in the
instrument cluster should start flashing, stop the car and let the
engine cool down by running it at idling speed for a few minutes.
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Care of vehicle and cleaning 244Care of vehicle and cleaningGeneral notesRegular care helps to maintain the value of the vehicle.Regular and careful care helps to maintain the value of the vehicle.
This may also be one of the requirements for upholding any
warranty claims in the event of corrosion or paint defects.
Audi dealers and specialist retailers carry stocks of suitable car care
products. Please follow the instructions for use on the packaging.
WARNING
•
Cleaning products and other materials used for car care can
damage health if misused.
•
Car care products can contain toxic substances and must
always be kept in a safe place out of reach of children.For the sake of the environment
•
When purchasing car care products, try to select ones which are
not harmful to the environment.
•
Surplus cleaning materials should not be disposed of together
with ordinary household waste.
Care of exteriorWa s hi ng t he ve hi c l eThe longer substances like insects, bird droppings, resinous tree
sap, road dirt, industrial deposits, tar, soot or road salt and other
aggressive materials remain on the vehicle, the more damage they do to the paintwork. High temperatures (for instance in strong
sunlight) further intensify the corrosive effect.
After the period when salt is put on the roads it is important to have
the underside of the vehicle washed thoroughly.
Automatic car washes
Before going through a car wash, be sure to take the usual precau-
tions such as closing the windows and sunroof. If the vehicle has
special accessories such as spoilers or a roof carrier or two-way
radio aerial, etc., it is advisable to consult the car wash operator.
It is best to use a car wash without revolving bristles if possible.
Washing your car with a high-pressure cleaner
When cleaning the vehicle with a high-pressure cleaner, always
follow the operating instructions for the equipment. This applies
particularly to the operating pressure and the spraying distance. Do
not hold the spray nozzle too close to soft materials, such as rubber
hoses or seals.
Do not use a nozzle that sprays the water out in a direct stream or
one that has a rotating jet for forcing off dirt.
Washing the car by hand
When washing the car by hand, use plenty of water to soften the dirt
first, and rinse off as well as possible.
Then clean the vehicle with a soft sponge, glove or brush, using only
slight pressure. You should start on the roof and work down. Special
car shampoo should only be used for very persistent dirt.
Rinse the sponge or glove thoroughly and often.
Wheels, sills and similar should be cleaned last. Use a second
sponge for this.
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Care of vehicle and cleaning245
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
WARNING
•
Do not wash the vehicle with the ignition switched on – risk of
accident.
•
Do not clean the underside of the car or inside the wheel arches
without protecting your hands and arms. You may cut yourself on
sharp metal parts.
•
Take care when washing the car during the winter: moisture
and ice on the brakes may affect braking efficiency – this could
cause an accident.Caution
•
Do not wash the vehicle in direct sunlight – otherwise the paint
can be damaged.
•
Do not use insect sponges or abrasive household sponges, etc.
– they can damage the surfaces.
•
The headlights should only be washed with water – do not wipe
them with a dry cloth or sponge. It is best to use soapy water.
•
Never wash tyres with a jet that sprays the water out in a direct
stream. This could damage the tyres – even if the spray is kept at a
distance and only used for a very short time.For the sake of the environment
The car should only be washed in special wash bays. This prevents
oily water from getting into the public drains. In some districts,
washing vehicles anywhere else may be prohibited.Waxing and polishingWaxing
Waxing protects the paintwork. It is time to apply a good coat of wax
when water no longer forms droplets and rolls off the clean paint-
work.Even if a wax solution is used regularly in the car wash, it is advis-
able to protect the paint with a coat of wax at least twice a year.
In the summer, you will find it is much easier to remove dead insects
(which accumulate on the bumper and the front of the bonnet) if the
car has been waxed recently.
Polishing
Polishing is only necessary if the paint has lost its shine, and the
gloss cannot be brought back by putting on wax.
The car must be waxed after polishing if the polish used does not
contain wax compounds to seal the paint.
Caution
Matt painted and plastic parts must not be treated with wax or
polish.Ornamental trim and mouldingsThe metal brightwork on the body is made of aluminium rather than
chrome (for environmental reasons).
Dirt or marks on the trim mouldings should be removed with an
acid-free cleaning agent (do not use a chrome cleaner). Body polish
is also unsuitable for use on trim mouldings. The intensive cleaning
fluids often used before the car goes into a car wash may contain
alkaline substances, which can cause dull or milky patches when
they dry out.
Audi dealers carry stocks of cleaning products which have been
tested for use on your vehicle and are not harmful to the
environment.
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Care of vehicle and cleaning 246Plastic partsPlastic parts will come clean with regular washing. If this is not suffi-
cient, plastic parts should only be treated with a special solvent-free
plastic cleaning agent. Do not use paint cleaners, polishes or wax on
plastic parts.Paint damageMinor damage to the paint, such as scratches or stone chips, should
be touched up without delay before the metal starts to corrode. Suit-
able touch-up brushes or sprays for your car can be obtained from
an Audi dealer.
The number of the original paint finish on the vehicle is given on the
data sticker ⇒page 321.
If corrosion is already visible it must be thoroughly removed by a
qualified workshop.Windows
Clear vision is an essential safety factor.The windscreen must not be cleaned with insect remover or wax,
otherwise the windscreen wipers will not function properly
(juddering).
Traces of rubber, oil, grease or silicone can be removed with a
window cleaning solution or a silicone remover. Wax residue can
only be removed with a special cleaner. Your Audi dealer will be able
to provide you with more detailed information.
The windows should also be cleaned on the inside at regular inter-
vals.
Use a separate cloth or chamois to dry the windows. Cloths used for
waxing and polishing contain residues that will cause smears on the
glass.
WARNING
Do not use water-repellent coatings on the windscreen. In bad visi-
bility conditions such as light rain, low sun or when driving at
night these coatings can cause increased dazzle, which is a
serious safety hazard. Such coatings can also cause the wiper
blades to judder.
Caution
•
Remove snow and ice from windows and mirrors with a plastic
scraper only. To avoid scratches caused by dirt on the glass, the
scraper should only be pushed in one direction and not moved to
and fro.
•
The heating element for the rear window is located on the inner
side of the window. To avoid damaging the heating element, do not
put stickers on the inner side of the window.
•
Never use warm or hot water to remove snow and ice from
windows and mirrors. This could cause the glass to crack!
Rubber seals (weatherstrips)The weatherstrips will remain pliable and last longer if they are
occasionally treated with a suitable care product (for example sili-
cone spray). This will also prevent premature ageing and leaks. The
doors will be easier to open as well. If they are kept pliable, the door
seals will be less likely to freeze up in the winter.WheelsThe wheels require regular attention to preserve their appearance.
It is important to remove road salt and brake dust by washing the
wheels at regular intervals, otherwise the finish will be impaired.
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Care of vehicle and cleaning247
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data After washing, the wheels should only be cleaned with an "acid-
free" cleaning agent for alloy wheels. This is available from Audi
dealers and specialist retailers. Never leave the cleaning agent on
the rims for any longer than specified in the instructions before
rinsing it off. If the wheel cleaner fluid contains acid it can attack the
surfaces of the wheel bolts.
Car polish or other abrasive agents should not be used. If the
protective paint coating is damaged by stone chips etc., the
damaged area should be touched up immediately.
WARNING
Please note when cleaning the wheels that water, ice and road salt
can impair the effectiveness of the brakes – this can cause an
accident.Care of interiorSound system / MMI* display screen and MMI control console*The display screen can be cleaned with a soft cloth and a special
“LCD cleaner” (available from retailers of electrical goods). Moisten
the cloth with a small amount of the cleaning fluid.
Clean the MMI control console with a fine brush first to prevent any
dirt from getting in between the control buttons and the housing.
We then recommend wiping the MMI control console using a cloth
moistened with washing-up liquid and water.
Caution
To avoid scratching the screen, do not wipe the display with a dry
cloth.
•
To avoid any possibility of damage, do not let any liquid get
inside the control console.
Plastic parts and leatherettePlastic parts and leatherette can be cleaned with a damp cloth. If
this is not sufficient, plastic parts and leatherette should only be
treated with a special solvent-free plastic cleaner.Textile covers and trim partsTextile covers and trim parts (e.g. seats, door trim) should be
cleaned regularly with a vacuum cleaner. This will remove surface
dirt which could otherwise be rubbed into the textile material
during use. Do not use steam cleaners, as the steam could carry the
dirt deeper into the textile material.
Normal cleaning
We recommend that you use a soft sponge or lint-free, micro-fibre
cloth for normal cleaning. Only use brushes on floor coverings and
mats, as other textile surfaces could become damaged.
In the case of normal surface dirt you can use a foam cleaner. Use a
sponge to spread the foam on the textile surface and to work it into
the material lightly. However, make sure that the textile material
does not become soaking wet. Then dab off the foam with a dry and
absorbent cloth (e.g. a micro-fibre cloth) and vacuum off any
residue once the surface is completely dry.
Removal of stains
To treat stains caused by spilled drinks (coffee, fruit juice or similar)
make up a solution with a mild detergent for sensitive fabrics and
apply it with a sponge. If the stains are difficult to remove, a
washing paste can be applied directly onto the stain and worked
into the fabric. The surface will then have to be wiped with clear
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Wheels and tyres 268Wheels and tyresWheelsGeneral notes–When driving with new tyres, be especially careful during
the first 500 km.
– If you have to drive over a kerb or similar obstacle, drive
very slowly and as near as possible at a right angle to the
kerb.
– Inspect the tyres regularly for damage (cuts, cracks or
blisters, etc.). Remove any foreign bodies embedded in
the treads.
– Damaged wheels and tyres must be replaced immedi-
ately.
– Keep grease, oil and fuel off the tyres.
– Replace any missing valve caps as soon as possible.
– Mark the wheels before taking them off so that they
rotate in the same direction when put back.
– When removed, the wheels or tyres should be stored in a
cool, dry and preferably dark place.New tyres
New tyres do not give maximum grip straight away and should
therefore be “run in” by driving carefully and at moderate speeds for
about the first 500 km. This will also help to make the tyres last
longer.
The tread depth of new tyres may vary, according to the type and
make of tyre and the tread pattern.Concealed damage
Damage to tyres and rims is often not readily visible. If you notice
unusual vibration or the car pulling to one side, this may indicate
that one of the tyres is damaged. Reduce speed immediately if there
is any reason to suspect that damage may have occurred. Inspect
the tyres for damage. If no external damage is visible, drive slowly
and carefully to the nearest qualified workshop and have the car
inspected.
Tyres with directional tread pattern
An arrow on the tyre sidewall indicates the direction of rotation on
tyres with directional tread. Always note the direction of rotation
indicated when mounting the wheel. This guarantees optimum grip
and helps to avoid aquaplaning, excessive noise and wear.
Tyre service life
Correct inflation pressures and sensible driving habits
will increase the service life of your tyres.– Check the tyre pressures at least once a month.
Fig. 261 Open driver's
door (LHD vehicle) with
sticker listing tyre
inflation pressures
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Wheels and tyres269
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
– The tyre pressures should only be checked when the
tyres are cold. The slightly raised pressures of warm tyres
must not be reduced.
– The pressures must be altered to suit major changes in
the load being carried.
– Avoid fast cornering and hard acceleration.
– Inspect the tyres for irregular wear from time to time.Tyre pressure and vehicle loading
The tyre pressure must be adjusted according to the load the vehicle
is carrying. We recommend adhering to the tyre pressure specifica-
tions for a maximum load. The tyre inflation pressures are listed on
a sticker on the end face of the driver's door ⇒page 268, fig. 261.
However, if you prefer an extra-smooth ride and the vehicle is not
fully loaded, you can select the tyre pressure for a normal load (no
more than three people travelling in the vehicle). However, should
you wish to drive with a full load you must increase the tyre pressure
to the specified maximum.
Under-inflation or over-inflation will reduce the life of the tyres
considerably and also impair the car's handling. Correct inflation
pressures are very important, especially at high speeds. The pres-
sures should therefore be checked at least once a month and before
starting a journey.
Do not forget the spare wheel* when checking the tyre pressures.
Keep the spare tyre inflated to the highest pressure required for the
road wheels.
Driving habits
Fast cornering, heavy acceleration and hard braking (squealing
tyres) all increase tyre wear.Wheel balancing
The wheels on new vehicles are balanced. However, various factors
encountered in normal driving can cause them to become unbal-
anced, which results in steering vibration.
Unbalanced wheels should be rebalanced, as they otherwise cause
excessive wear on steering, suspension and tyres. A wheel must
also be rebalanced when a new tyre is fitted or if a tyre is repaired.
Incorrect wheel alignment
Incorrect wheel alignment causes excessive tyre wear, impairing the
safety of the vehicle. If you notice excessive tyre wear, contact your
Audi dealer.
WARNING
•
Always adapt the tyre pressure accordingly when the vehicle
load changes.
•
Under-inflated tyres flex more and can overheat at continuous
high speeds. This can cause tread separation and tyre blow-out,
which could result in an accident.For the sake of the environment
Under-inflated tyres will increase the fuel consumption.
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Wheels and tyres 270Tread wear indicators
The tread wear indicators show the condition of the tyre
treads.The original tyres on your vehicle have 1.6 mm high “tread wear
indicators” ⇒fig. 262 running across the tread. Depending on the
make, there will be 6 to 8 of them spaced at equal distances around
the tyre. Markings on the tyre sidewall (for instance the letters “TWI”
or a triangle) indicate the positions of the tread wear indicators.
The minimum tread depth required by law in Germany is 1.6 mm
(measured in the tread grooves next to the tread wear indicators).
Other specifications may apply in export countries.
WARNING
To avoid putting safety at risk, the tyres must be replaced at the
latest when the tread is worn down to the tread wear indicators.•
Especially in difficult driving conditions such as wet or icy
roads, it is important that the tyres have sufficient tread depth.
The tread depth should same on the tyres of both the front and the
rear axles.
•
The decrease in driving safety due to insufficient tread depth is
particularly evident in vehicle handling, when there is a risk of aquaplaning in deep puddles of water and when driving through
corners. Braking is also adversely affected.
•
The speed has to be adapted accordingly, otherwise there is a
risk of losing control over the vehicle.
Changing wheels roundTo ensure that the wear is equal on all tyres the wheels should be
changed round from time to time according to the system
⇒fig. 263. All the tyres will then last for about the same time.Replacing wheels and tyres
It is important to use the correct wheels and tyres when
replacement is necessary.– All four wheels must be fitted with tyres of the same type,
size (rolling circumference) and preferably the same
tread pattern.
– If possible, tyres should be replaced at least in pairs and
not individually (i.e. both front tyres or both rear tyres
together).
Fig. 262 Tyre tread:
Tr e a d w e a r i n d i c a t o r s
WARNING (continued)
Fig. 263 Changing
wheels round
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