wheel AUDI TT ROADSTER 2008 Service Manual

Cleaning and prote ction BIii
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•
Ap plies to vehi cles : w it h C ast a llo y wh eels
Cast (light) alloy wheels
Cast (light) alloy wheels require special care.
-Wash the wheels w ith a sponge or hose brush eve ry
ot her week .
- For de ep cleaning afterwar ds, use only a dedicated
acid ­
free cast alloy wheel cleaner .
- Ru b a c oat of
liquid wax on to t he rims every t hree mon th.
B e sure t o reach and treat all parts of the rim .
To preserve the decora tive appearance of the cas t alloy whee ls,
some special care is necessary . In addition to road dirt and sa lt ,
b rake dust is also co rro sive . If left o n fo r to o long, brake dust can
cause pitting .
Use only special
ac id -free cleaners formulated for alloy rims . Safe
products are available at your Audi dea ler . Never leave the cleaner
on the r ims longer than specified on the label. If not rins ed off
promp tly, the acid contained in some cleaners can a ttack the
threads on the wheel bolts .
Never use abrasive or me tal po lishing cleaning agents . If the protec ­
tive coat ing has been chipped, e .g . by kicked up road dirt. touch it
up as soon as possib le .
& WARNING
• Moi sture and ice on brakes may affect braking efficiency
=> page 188 , "General information ". Te st the b rake s c arefully ea ch
time you wash the vehicle.
• Alway s read a nd heed all WARNINGS and other informat ion
=> page 200 . •
Body cavity sealing
T he body c avity sealing d oes not need t o be checke d.
A ll body cavities which could be aff ected by corrosion hav e been
given thor ough protecti on a t the facto ry.
This sealing does not require any inspection or add itional treat ­
ment . If any wax shou ld seep out of the cavity when the ambient
tempera ture is high , it can be removed wi th a p las tic sc raper and a
suitable solvent.
& WARNING
Solvent s can be dangerous.
• Benz ine is flammable and to xic . If you use benz ine for removing
the wax , keep sparks , flame and lighted cigarettes away . Never
dump benz ine on the ground , into open streams or down sewage
drains .
• Be sure to observe all safety and environmental regulat ions .
Follow all instru ctions on the container.
• Always read and heed all WARNINGS and the information
=> page 200 . •
Chassis
Have the undercoa ting checked for damag e from time to
time .
The lowe r body shell of your Audi is a lso thoroughly protected
against corros ion.
Any damage to the undercoating caused by road ha za rds sh ould be
repaired promp tly .
& WARNING
Too much unde rcoat ing in the wrong pla ces can cause a fire .
Vehicle care
I t •

Cleaning and protection -
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•
& WARNING (continued )
• Before reaching into the front plenum panel , always remove the
ignition key . Otherwise , the windshield wiper system could unin ­
tent ionally be sw itched on, possibly caus ing personal injury from
the moving wiper linkage.
• Never reach into the area around or touch the radiator fan. The
auxiliary fan is temperature controlled and can switch on suddenly
- even when the ignition is off .
• Do not wash, wax or dry the engine with the engine running .
Moving or hot parts could injure you .
• Do not clean the underside of the chassis , fenders, wheel
covers , or other hard to reach parts without protecting your hands
and arms. You may cut yourself on sharp-edged metal parts .
• Always read and heed all WARNINGS and other information
=> page 200. •
Vehicle care I t •

-~_T_ ir_e_ s_ a_ n_d _ w_ h_ e_e _l_s _________________________________________________ _
Tires and wheels
Tires
General notes
Tires may be the least appreciated and most abused parts
of a motor vehicle.
Tires may be the least appreciated and most abused parts of a
motor vehicle. Tires are, however, one of the most important parts
of a vehicle, particu larly considering the comparatively small patch
of rubber on each tire that assures that all -important contact
between you, your vehic le and the road.
Maintaining the correct tire pressure, making sure that your vehicle
and its tires do not have to carry more weight than they can safely
handle, avoiding damage from road hazards and regularly inspecting tires for damage inc luding cuts, s lashes irregular wear
and overa ll condition are the most important things that you can do
to help avoid sudden tire failure including tread separation and
blowouts.
A vo iding d am age
If you have to drive over a curb or similar obstac le, drive very slowly
and as close as possible at a right angle to the curb.
A lways keep chemica ls including grease, oi l, gaso line and brake
fluid off the tires.
Inspect the ti res regu larly for damage (cuts, cracks or b listers, etc.l .
Remove any foreign bodies embedded in the treads.
Storing tir es
Mark tires when you remove them to indicate the direction of rota ­
t ion. This ensures you to be able to mount them correctly when you
reinstal l them. When removed, the wheels or tires shou
ld be stored in a coo l, dry
and preferably dark place.
S tore tires in a vertical pos it ion if they a re not mounted on r ims, in
a horizonta l position if they are mounted on rims.
New tir es
New tires have to be broken in=>&.
The tread depth of new ti res may vary, according to the type and
make of tire and the tread pattern.
H idd en damage
Damage to tires and rims is often not readily visible. If you notice
unusual vibration or the vehicle pu lls to one s ide, this may indicate
that one of the tires has been damaged . The tires must be checked
immediately by an authorized Audi dealer or qualified workshop .
Unidire cti ona l t ires
A unidirectional tire can be identif ied by arrows on the sidewa ll, that
point in the direction the tire is designed to rotate . You must fo llow
t he specified directio n of rotation . This is necessary s o that these
tires can develop their optimum characteristics regarding grip, road noise, wear and hydrop laning resistance . For more information
=>
page 272.
& WARNING
New t ires o r ti re s th at a re old , worn or d am aged cann ot pro vid e
maximum cont rol and braking ability .
• New tires te nd to be slippery and mu st be bro ken in . To redu ce
the ri sk o f lo sin g co ntro l, a collis ion and serious per sonal injurie s,
dri ve w ith special care f or the fi rst 350 m ile s ( 560 km l.
• Driving w ith w orn or damaged tire s can lead to lo ss of control ,
sudd en tir e fa ilure , inc ludi ng a blowout a nd sudden defl atio n, ..,_

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& W ARNING (continu ed )
crashes and serious personal in jur ies . Have worn or da maged t ires
replaced immediately .
• Tires age even if they are not being u sed and can fail suddenly ,
especially at high speeds. T ires that are more than 6 years old can
only be used in an emergency and then w ith special care and at
low speed.
Glossary of tire and loading terminology
Accessory weight
means the co mbined we ig ht ( in excess o f those sta nda rd items
which may be rep laced) of automatic transmission, power steering,
power brakes, power w indows, powe r seats, rad io, a nd heater, to
the extent that these items are avai lab le as factory-installed equip­
m ent (w hether insta lled or not).
Aspect ratio means t he ratio o f th e height to t he w idt h of the tire in perce nt.
N umbers of 55 or lower indicate a low sidewa ll for improved
steer ing respo nse and b ette r overall ha ndl ing on dry pave ment.
Bead
means the part of the tire that is made of stee l wires, wrapped or
reinforced by ply cords and that is shaped to fit the rim.
Bead separation
means a breakdow n of the bond be tween co mponents i n the bead.
Cord
m eans the strands fo rmi ng the plies in the ti re.
& W ARNING (continued )
• Never mount used tires on your vehicle if you are not sure of
their "previous history. " Old used t ire s may ha ve been damaged
even though the damage cannot be seen that can lead to sudden
tire failure and lo ss of vehicle control.
• If you noti ce unusual vibration or if the vehicle pulls to one side
when driving , always stop as soon as it is safe to do so and check
the wheels and tires for damage . •
Cold tire inflation pressure
mea ns t he ti re pressure reco mm ended by the ve hicle ma nufacturer
for a tire of a designated size that has not been d riven for more tha n
a cou ple o f miles (k ilometers) at low speeds in t he t hre e ho ur per iod
before the tire pressure is measured or ad justed .
Curb weight
means the weight of a moto r vehic le with standard equipment
i nc lud ing the max imu m capac ity o f fue l, o il, and coola nt, a ir c ond i­
tioning and additiona l weight of optional equipment.
Extra load tire
means a tire designed to ope rate at higher loads and at higher infla­
tion pressures than the corresponding standard tire. Extra load tires
my be identified as "XL", "xi", "EX TRA LOAD", or "RF" on the side ­
wa ll.
Gross Axle Weight Rating ("GAWR ")
means the load -carrying capacity of a sing le ax le system, measured
at the ti re -ground interfaces.
Gross Vehicle Weight Rating ("GVWR "l
mea ns the ma ximum tot al l oade d weigh t of the vehicle.
Vehicle care
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-~_T_ ir_e_ s_ a_ n_d _ w_ h_ e_e _l_s _________________________________________________ _
Groove
means the space between two adjacent tread ribs.
Load rating (code)
means the maximum load that a tire is rated to carry for a given
inflation pressure . You may not find this information on all tires
because it is not required by law.
Maximum load rating
means the load rating for a tire at the maximum permissible infla­
tion pressure for that tire.
Maximum loaded vehicle weight
means the sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight, and
(d) Production options weight
Maximum (permissible) inflation pressure
means the maximum cold inflation pressure to which a tire may be
in flated. Also called "maximum inflation pressure ."
Normal occupant weight
means 150 lbs. (68 kilograms) times the number of occupants
seated in the vehicle up to the total seating capacity of your vehicle.
Occupant distribution
means distribution of occupants in a vehicle .
Outer diameter
means the overall diameter of an inflated new tire.
Overall width
means the linear distance between the exteriors of the sidewalls of
an inflated tire, including elevations due to labeling, decorations, or
protective bands or ribs .
Ply
means a layer of rubber -coated parallel cords.
Production options weight
means the combined weight of those installed regular production
options weighing over 5 lbs. (2.3 kg) in excess of those standard
items which they replace, not previously considered in curb weight
or accessory weight, including heavy duty brakes, ride levelers,
heavy duty battery, and special trim.
Radial ply tire
means a pneumatic tire in which the ply cords that extend to the
beads are laid at substantially 90 degrees to the centerline of the
tread.
Recommended inflation pressure
see =:> page 239, "Cold tire inflation pressure".
Reinforced tire
means a tire designed to operate at higher loads and at higher infla­
tion pressures than the corresponding standard tire. Reinforced
tires my be identified as "XL", "xi", "EXTRA LOAD", or "RF" on the
sidewall.
Rim
means a metal support for a tire or a tire and tube assembly upon
which the tire beads are seated .
Rim diameter
means nominal diameter of the bead seat. If you change your wheel
size, you will have to purchase new tires to match the new rim diam ­
eter.
Rim size designation
means rim diameter and width.
Rim width
means nominal distance between rim flanges .

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ating the vehicle at ma ximum load , you must increase the t ire pre s­
sures to those specified for maximum vehi cle load
~ & .
Bear in mind that the t ire pressure mo nitoring system can only
monitor the tire pressures you have stored . The system does not
reco gnize the load cond itio n of your vehicle.
T he effectiveness of the tire pressure monitoring system will be
impaire d if you stor e nor mal loa d pressures but then operate the
vehic le at its maximum load~&. See the
illustration~ page 242, fig. 160 for the location of the label
on driver's si de B -pillar (co lor of the ac tual label a nd exact loca tion
on the veh ic le will vary slightly).
N ote that the following tab le is accu rate at the time of going to
press and is subject to cha nge . In t he event o f discrepancies, the t ire
pressure label (on driver's side B -pillar) a lways takes precedence .
The table belo w lists t he r ecom mend ed cold tire i nflatio n pressures
for the Audi mode l covered by your Owner's Literature at the
vehic le' s capacity weigh t and the tire size s insta lled o n the respec ­
tive models as original equipment , or as a factory option .
Engine Tire designation
Tire pressure front II Tire pressure rear
(displace -
= " full load full load
ment in normal load
condition normal
load
condition
liter ) condition
(up to condition (up
( 2 oc cupants (2 occupants
2 o ccupants ) to 2 occupants)
plus luggage) plus luggage)
I
PSI II kPA PSI II kPA II PSI II kPA
PSI I[ kPA I
I
4-cylinder
225/50 R17 94H All Season 32 220 3 2 220 29 200 29 200
2.0
245/40 R18 93H All Season 32 220 32 220 29 200 29 200
245 /40 R18 93Y XL High Performance 32 220 32 220 29 200 29 200
255 /35 R19 95Y XL High Performance 32 220 32 220 29 200 29 200
6 -cylinder 245/45 R17 95H All Season 3 2 220 32 2 20 29 200 29 2 00
3.2
245/40 R18 93H All Season 32 220 32 220 29 200 29 200
245 /40 R18 93V XL High Performance 32 220 3 2 220 29 200 29 200
255/35 R19 95V XL High Performance 32 2 20 32 220 29 200 29 200
XL = reinforced
T he correct tire pressure for the spare wheel is located on a label on the tire p ressure label on your vehicle with the tires on your vehic le.
t he d river's s ide B -pilla r. Make sure that the tire s ize inf ormat ion on t he veh icle labe l is t he
Because technical changes may be made to vehicle equipment same as the si
ze of the tires on the vehicle. This is especially impor -
t ant if the ve hicle belongs to so meo ne else or you bought the
dur ing th e mode l year, always co mpare the tire size designa tion on
Vehicle care
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.,

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pressure for a trip - even one that you would not consider to be
"long." See=>
page 246, "Tires and vehicle load limits" for more
important information .
Always use an accurate tire pressure gauge when checking and adjus ting inflation pressures . Check all of the tires and be sure not
to forget the spare tire . If the pressure in any tire is too high when
the tire is "cold," let air out of the tire slowly with the edge of the tire gaug e and keep checking the pressur e until you reach the pressure
that is correct for the load (passengers and luggage) and kind of driving you plan to do.
I f the pressure in any tire is too low, note the difference between the
pressure in the cold tire and the pressure you need and add the air
that you need to reach the correct pressure for the vehicle load
(passengers and luggage) for the tires on your vehicle as listed on
the on your vehicle and in this manual and the kind of driving you
plan to do.
Ne ver e xceed the m aximum inflat ion pre ssure l isted on the tire
sid ewall for any rea son .
Remember that the veh ic le manufacturer, not the tire manufacturer ,
determin es the correct tire pressure for the tires on your vehicle .
It is important to check the tire pressure when the tires are cold .
• Read the required tire pressure from the tire pressure label
located on driver 's side 8 -pillar.
• T urn the va lve stem cap counter -clockwise to remove it from the
tire valve .
• Place the air pressure gauge on the valve .
• The tire pressures should only be checked and adjusted when
the tires are cold. The s lightly raised pressures of warm tir es mus t
not be reduced.
• Adjust the tire pressure to the load you are carrying .
• Reinstall the va lve stem cap on the valve .
When should I ch eck the tir e pr essu re?
The correct tire pressure is especially important a t high speeds . The
pressure should therefore be checked a t least once a month and
a lways before sta rting a journey.
Wh en sho uld I adjust the tire p re ss ure s?
Adjust the tire pressure to the load yo u are carrying . After changing
a wheel
o r replacing wheels you have to adjust the tire pressures on
a ll whee ls . In addition, you must then initia lize the new tire pres ­
sures in the tire pressure monitoring system=>
page 41.
& WARNING
Incorre ct t ir e pre ssures and /or underinfl ati on ca n lead sudden tire
failure , los s of contro l, colli sion , seriou s per sonal injury or even
death .
• Whe n the w arnin g sy mbol appear s in the instrument
cl uster , sto p and in spe ct the tire s.
• Inco rre ct tire pre ssure and /or underin flati on can cau se
in creased tire wear and can affe ct the ha ndling of the vehicle and
s topping ability.
• Incorre ct t ire pre ssures and /or underinfl atio n c an a ls o le ad to
s udden tire f ailure , including a blowout and sudden deflation ,
ca usi ng loss o f vehi cle co ntrol.
• The driv er i s re sp o nsible for the correct tire p re ss ure s for all
tire s on the vehicle . T he appl icable pre ssure v alu es are lo ca ted o n
a stic ker on th e driver 's side B -pillar.
• Onl y w hen all tire s on th e veh icle a re fi lled to the corre ct pre s­
s ure , the tire pre ssure monitor ing sy ste m can work correctly .
• The u se of incorre ct t ire pr essure val ues can lead to accidents
or other d am age. The refo re it is esse ntial th at the dri ver ob serve
the spe cified tire pr essur e value s fo r the t ire s and the correc t pr es­
s ures for the function of the tire pr essure monitoring sy stem.
• Always inflate t ires to the r ecom mended and corre ct tir e pr es -
su re bef ore dri ving off.
~
Vehicle care I t •

-~_T_ ir_e_ s_ a_ n_d _ w_ h_ e_e _l_s _________________________________________________ _
& WARN ING (continued )
• Driving with underinflated tires bend more , letting them get
too hot re sulting in t read separation , sudden t ire failure and loss
of control.
• Excessive speed and /overloading can cau se heat bu ild-up ,
sudden tire failure and lo ss of control.
• If the tire pressure is too low or too high , the tires will wear
prematurely and the vehicle will not handle well .
• If the tire is not flat and you do not have to change a wheel
immediately, drive at reduced speed to the nearest service station
to che ck the tire pres sure and add air as required .
0 Note
Driving without valve stem caps can cause damage to the tire
va lves. To prevent this, always ma ke sure that fact ory insta lled valve
stem caps on all whee ls are securely mounted on the valve .
<£> For the sake of the environment
Underinflated tires will also increase the fue l consumption. •
Tires and vehicle load limits
There are limits to the amount of load or weight that any vehicle and
any tire can carry. A vehicle that is overloaded will not handle well
and is more difficu lt to stop. Overload ing can not only lead to loss
of vehicle contro l, but can a lso damage important parts of the
veh ic le an d ca n lead to sudden t ire fa ilu re , inc lud ing a bl owout a nd
sudden deflation that can cause the vehicle to crash.
Yo ur saf ety a nd that of you r passenge rs also de pends on making
sure that load limits are not exceeded . Vehicle load includes every ­
body and eve ryt hing in and on the vehic le . Th ese load limi ts are technica
lly referred to as the vehicle's
Gross Vehicle We ight Rating
("GVWR").
Th e "GVWR" includes the weight of the basic vehicle, all factory
insta lled accessories, a ful l tank of fuel, oil, coolant and other f luids
p lus max imum load. The ma ximu m load inc ludes the numbe r of
passengers that the vehicle is intended to carry ("seating capacity")
w it h an assu med we ight o f 150 lbs (68 kg) for eac h pass enger at a
designated seating position and the total weight of any luggage in
t he vehicle.
T he
Gross Axle Weight Rating ("GAWR"l is the maximum load that
can be a pplied a t eac h of the vehic le's two a xles .
T he Gross Veh icle Weigh t Rat ing a nd the Gross A xle We igh t R ating
are listed on the safety comp liance stic ker label located on the
dr iver's s ide B -p illar . You r Aud i has 2 sea ting pos it io n s. Eac h seating
posit ion has a safety belt=>
page 137, "Safety belts".
T he fact that the re is a n up per lim it to yo ur vehicle's G ross Veh ic le
We ig ht Rating means that the to tal we ight o f what ev e r is be ing
ca rried in the ve hicle is lim ited. The mo re pas se ngers in the vehic le
or passe ngers w ho ar e heav ier t han th e sta ndard weights assumed
mean that less weight can be carried as luggage.
T he ti re p ress ure labe l on yo ur Aud i al so list s the maxi mum
combined weight of a ll of the occupants and luggage or other cargo
th at the vehicle can car ry. F or the lo ca tio n of t he label =>
page 242,
fig . 160.
& WARNING
Overloading a vehicle can cause loss of vehicle control , a crash or
other accident, serious personal injury , and even death .
• Carrying more weight than your vehicle was des igned to carry
will prevent the vehicle from handling properly and increase the risk of the loss of vehi cle control .
• The brakes on a vehicle that has been overloaded may not be
able to stop the vehicle within a safe distance. .,_

& WARNING (continued)
• Tires on a vehicle that has been overloaded can fail suddenly,
including a blowout and sudden deflation , causing loss of control
and a crash .•
Determining correct load limit
Use the example below to calculate the
total weight of the passengers and
luggage or other things that you plan to
transport so that you can make sure that
your vehicle will not be overloaded.
Steps for Determining Correct
Load Limit
1. Locate the statement "THE COMBINED
WEIGHT OF OCCUPANTS AND CARGO SHOULD NEVER EXCEED XXX KG OR XXX
LBS"on your vehicle 's placard (tire infla­
tion pressure label)=;>
page 242, fig. 160.
2. Determine the combined weight of the driver and passengers that will be riding
in your vehicle.
Tires and wheels 1111111
3. Subtract the combined weight of the driver and passengers from
"XXX" kilo­
grams or
"XXX" pounds shown on the
sticker =;>
page 242, fig. 160.
4. The resulting figure equals the available amount of cargo and luggage load
capacity. For example, if the
"XXX"
amount equals 1400 lbs. and there will be five 150 lbs. passengers in your
vehicle, the amount of available cargo and luggage load capacity is 650 lbs.
( 1400 -750 (5 x 150) = 650 I bs.)
5. Determine the combined weight of
luggage and cargo being loaded on the
vehicle. That weight may not safely exceed the available cargo and luggage
load ca pa city calculated in Step 4.
6. If your vehicle will be towing a trailer, load from your trailer will be transferred
to your vehicle. Consult this manual to determine how this reduces the avail­
able cargo and luggage load capacity of
your vehicle. .,_
Vehicle care I • •

___ T_ i_ r_e _s_ a_ n_ d_ w_ h_ e_ e _ ls _________________________________________________ _
Check the tire sidewall (=> page 249,
fig. 164) to determine the designated
load rating for a specific ti re. •
Tire service life
The service life of tires depends on a lot of different things
including proper installation and balancing, correct tire
pressure and driving style.
Tread Wear Indicator (TWll
"' M
J
Fig. 162 Tir e tread:
tre ad we ar indi cator s
(TWll
Fig . 163 Rotating tires
for more even wear
The original tires on your veh icle have 1/16 inch (1.6 mm) high "wear
indicators" => fig . 162 running across the tread. Depending on the make, there will be six to eight of them evenly p
laced around the
t ire. Marks on the tire sidewall (for example "TWI" or other symbols)
indicate the positions of the tread wear indicators. Worn tires must
be rep laced. Different figures may apply in other countries =>& .
Tire p ressure
Incorrect tire pressure causes premature wear and can cause
sudden tire blow-out . Forth is reason, tire pressure must be checked
at least once a month
==> page 244.
Driving style
Driving fast around curves, heavy acceleration and hard braking
increase tire wear.
Rotating tires for more even wear
For all four tires on your vehicle to have the same service life, we
recommend that the front and rear tires are rotated according to the
tire manufacturer 's suggested tire rotation intervals. Please
remember the following:
• Tire rotation interva ls may differ from the vehicle service inter­
vals outlined in your Maintenance and Warranty Booklet .
• The longer one tire is used in one location on the vehicle, the
more it wears at certain points; therefore, we recommend that you
follow the tire manufacturer's suggested tire rotation intervals.
• Vehicles with front-wheel drive experience more tread wear on
the front wheels compared to a ll-wheel drive (quattro®l .
• Please rotate tires as shown ;;:;:, fig. 163.
• Extra care must be taken when rotating direction -specific tires
==> page 272.
Wheel balancing
The wheels on new vehicles are balanced. However, various situa­
tions during everyday driving can cause them to become unbal ­
anced, resulting in vibrations you can usual ly feel through the
steering wheel. ...