wheel SAAB 9-3 2007 Repair Manual

243 Car care
certain that all wheel nuts are properly tight-
ened. See page 258.
Flat spottingAll tires get hot, especially on long journeys
or when the car is driven hard. After the car
has been parked with hot tires and the tires
have cooled down, a flat spot can form in the
tire, where it is in contact with the ground.
The same can occur if the car has not been
moved for a long time.
Flat spots can cause vibration that can be
felt through the steering wheel, similar to
that experienced when the wheels need bal-
ancing.
Flat spots of this type disappear once the
tires get hot again, usually after 10–15 miles
(20–25 km) of driving at cruising speed. If
the outdoor temperature is low it takes a
longer distance.
When It Is Time for New TiresOne way to tell when it’s time for new tires is
to check the treadwear indicators, which will
appear when your tires have only 1/16 inch
(1.6 mm) or less of tread remaining.
You need a new tire if any of the following
statements are true:
You can see the indicators at three or
more places around the tire.
You can see cord or fabric showing
through the tire’s rubber.
The tread or sidewall is cracked, cut or
snagged deep enough to show cord or
fabric.
The tire has a bump, bulge or split.
The tire has a puncture, cut or other
damage that can’t be repaired well
because of the size or location of the
damage.
WARNING
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after a time. The wheel
could come off and cause an accident.
When you change a wheel, remove any
rust or dirt from places where the wheel
attaches to the vehicle. In an emergency,
you can use a cloth or a paper towel to do
this; but be sure to use a scraper or wire
brush later, if you need to, to get all the
rust or dirt off. See “Changing a tire” on
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244 Car careTreadwear indicatorsThe tires incorporate wear indicators in the
form of smooth, treadless strips across the
width, which become visible when only
2/32" (1.6 mm) of tread remains. As soon as
the indicators become visible, new tires
should be fitted without delay.
Make sure you are familiar with the legal
limit for minimum tread depth in your
country and also any regulations gov-
erning the use of winter (snow) tires.
Buying New TiresTo find out what kind and size of tires you
need, look at the Tire-Loading Information
label.
Before changing to wheels/tires of another
size, we recommend that you contact an
authorised Saab workshop regarding
acceptable options. See also page 290
Wheels/tires combinations that are not
approved by Saab can negatively affect the
car’s directional stability, steering and brak-
ing in both wet and dry conditions.The wheels and tires have been carefully
matched to the characteristics of the car and
play a key role in its outstanding roadhold-
ing and handling.
Do not take it for granted that a wheel/tire
combination will work in the best possible
way, just because it can be fitted to the car.
To ensure that the speedometer is as accu-
rate as possible it should be reprogrammed
if wheels of a different dimension are fitted.
Contact a Saab dealer.
Because of front wheel drive, the front tires
tend to wear faster than the rear ones. New
tires should always be fitted in pairs, so that
tires on the same axle have the same
amount of tread.
Store wheels lying flat or hanging – never
standing upright.
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245 Car care

Uniform Tire Quality GradingQuality grades can be found where applica-
ble on the tire sidewall between tread shoul-
der and maximum section width. For exam-
ple:
Treadwear 200 Traction AA
Temperature A
The following information relates to the
system developed by the United States
National Highway Traffic Safety Administra-
tion, which grades tires by treadwear, trac-
tion and temperature performance. (This
applies only to vehicles sold in the United
States.) The grades are molded on the side-
walls of most passenger car tires. The Uni-
form Tire Quality Grading system does not
apply to deep tread, winter-type snow tires,
space-saver or temporary use spare tires,
tires with nominal rim diameters of 10 to 12
inches (25 to 30 cm), or to some limited-pro-
duction tires.
While the tires available on General Motors
passenger cars and light trucks may vary
with respect to these grades, they must also
conform to federal safety requirements and
additional General Motors Tire Perfor-
mance Criteria (TPC) standards.
NOTICEWide wheels and tires with side walls that
are too low can:
be damaged in potholes, etc.
cause springs, shock absorbers and
wheel bearings and body mountings
to be overloaded.
affect the function of the Electronic
Stability Program (ESP
®).
The speed and load limits of the tires
must not be exceeded; see page 250.
Wheels larger than 17" must not be fitted
on the Saab 9-3 for reasons above. The
permissible offset is 1.61 inch (41 mm).
WARNING
Mixing tires could cause you to lose
control while driving. If you mix tires of
different sizes or types (radial and bias-
belted tires), the vehicle may not handle
properly, and you could have a crash.
Using tires of different sizes may also
cause damage to your vehicle. Be sure to
use the same size and type tires on all
wheels. It’s all right to drive with your
compact spare temporarily, it was devel-
oped for use on your vehicle. See
“Compact spare” on page 254.
WARNING
If you use bias-ply tires on your vehicle,
the wheel rim flanges could develop
cracks after many miles of driving. A tire
and/or wheel could fail suddenly, causing
a crash. Use only radial-ply tires with the
wheels on your vehicle.
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246 Car careTreadwear
The treadwear grade is a comparative
rating based on the wear rate of the tire
when tested under controlled conditions on
a specified government test course. For
example, a tire graded 150 would wear one
and a half (1.5) times as well on the govern-
ment course as a tire graded 100. The rela-
tive performance of tires depends upon the
actual conditions of their use, however, and
may depart significantly from the norm due
to variations in driving habits, service prac-
tices and differences in road characteristics
and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades repre-
sent the tire’s ability to stop on wet pave-
ment as measured under controlled condi-
tions on specified government test surfaces
of asphalt and concrete. A tire marked C
may have poor traction performance. Warn-
ing: The traction grade assigned to this tire
is based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.Temperature – A, B, C
The temperature grades are A (the highest),
B, and C, representing the tire’s resistance
to the generation of heat and its ability to dis-
sipate heat when tested under controlled
conditions on a specified indoor laboratory
test wheel. Sustained high temperature can
cause the material of the tire to degenerate
and reduce tire life, and excessive temper-
ature can lead to sudden tire failure. The
grade C corresponds to a level of perfor-
mance which all passenger car tires must
meet under the Federal Motor Vehicle
Safety Standard No. 109. Grades B and A
represent higher levels of performance on
the laboratory test wheel than the minimum
required by law.
Warning: The temperature grade for this tire
is established for a tire that is properly
inflated and not overloaded. Excessive
speed, underinflation, or excessive loading,
either separately or in combination, can
cause heat buildup and possible tire failure.
Wheel Alignment and Tire
BalanceThe wheels on your vehicle were aligned
and balanced carefully at the factory to give
you the longest tire life and best overall per-
formance.
Scheduled wheel alignment and wheel bal-
ancing are not needed. However, if you
notice unusual tire wear or your vehicle pull-
ing one way or the other, the alignment may
need to be reset. If you notice your vehicle
vibrating when driving on a smooth road,
your wheels may need to be rebalanced.
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247 Car care
Wheel ReplacementReplace any wheel that is bent, cracked or
badly rusted or corroded. If wheel nuts keep
coming loose, the wheel, wheel bolts and
wheel nuts should be replaced. If the wheel
leaks air, replace it (except some aluminum
wheels, which can sometimes be repaired).
See your dealer if any of these conditions
exist.
Your dealer will know the kind of wheel you
need.
Each new wheel should have the same
load-carrying capacity, diameter, width,
offset and be mounted the same way as the
one it replaces.
If you need to replace any of your wheels,
wheel bolts or wheel nuts, replace them only
with new Saab original equipment parts.
This way, you will be sure to have the right
wheel, wheel bolts and wheel nuts for your
vehicle.
Notice:
The wrong wheel can also cause
problems with bearing life, brake cool-
ing, speedometer or odometer calibra-
tion, headlamp aim, bumper height, vehi-
cle ground clearance and tire or tire
chain clearance to the body and chassis.
See “Changing a tire” on page 257.Used Replacement Wheels
WARNING
Using the wrong replacement wheels,
wheel bolts or wheel nuts on your vehicle
can be dangerous. It could affect the
braking and handling of your vehicle,
make your tires lose air and make you
lose control. You could have a collision in
which you or others could be injured.
Always use the correct wheel, wheel bolts
and wheel nuts for replacement.
WARNING
When fitting just one new pair of tires,
these should be fitted to the rear wheels,
as these are more critical to the direc-
tional stability of the car (e.g. on braking
or in a skid). The existing rear wheels
should therefore be moved to the front.
WARNING
Putting a used wheel on your vehicle is
dangerous. You can’t know how it’s been
used or how far it’s been driven. It could
fail suddenly and cause a crash. If you
have to replace a wheel, use a new GM
original equipment wheel.
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248 Car careTire Chains
Notice:
If your vehicle does not have
235/45R17 size tires, use tire chains only
where legal and only when you must.
Contact your Saab dealer regarding suit-
able snow chains. Install them on the
front tires and tighten them as tightly as
possible with the ends securely
fastened. Drive slowly and follow the
chain manufacturer’s instructions. If you
can hear the chains contacting your
vehicle, stop and retighten them. If the
contact continues, slow down until it
stops. Driving too fast or spinning the
wheels with chains on will damage your
vehicle.
If a Tire Goes FlatIt’s unusual for a tire to “blowout” while
you’re driving, especially if you maintain
your tires properly. If air goes out of a tire,
it’s much more likely to leak out slowly. But
if you should ever have a “blowout”, here are
a few tips about what to expect and what to
do:
If a front tire fails, the flat tire will create a
drag that pulls the vehicle toward that side.
Take your foot off the accelerator pedal and
grip the steering wheel firmly. Steer to main-
tain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts
much like a skid and may require the same
correction you’d use in a skid. In any rear
blowout, remove your foot from the acceler-
ator pedal. Get the vehicle under control by
steering the way you want the vehicle to go.
It may be very bumpy and noisy, but you can
still steer. Gently brake to a stop – well off
the road if possible.
If a tire goes flat, the next part shows how to
use your jacking equipment to change a flat
tire safely.
WARNING
If your vehicle has 235/45 R17 size tires,
don’t use tire chains, there’s not enough
clearance.
Tire chains used on a vehicle without the
proper amount of clearance can cause
damage to the brakes, suspension or
other vehicle parts. The area damaged by
the tire chains could cause you to lose
control of your vehicle and you or others
may be injured in a crash.
Use another type of traction device only if
its manufacturer recommends it for use
on your vehicle and tire size combination
and road conditions. Follow that manu-
facturer’s instructions. To help avoid
damage to your vehicle, drive slowly,
readjust or remove the device if it’s
contacting your vehicle, and don’t spin
your wheels.
If you do find traction devices that will fit,
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250 Car careAspect ratio: A two-digit number that indi-
cates the tire height-to-width measure-
ments. For example, if the tire size aspect
ratio is “55”, as shown in item “C” of the illus-
tration, it would mean that the tire´s sidewall
is 55% as high as it is wide.
Belt Rating: A letter code is used to indicate
the type of ply construction in the tire. The
letter “R” means radial ply construction; the
letter “D” means diagonal or bias ply con-
struction; and the letter “B” means belted-
bias ply construction.
Rim Diameter: Diameter of the wheel in
inches.
Load range: The load range represents the
load carry capacity a tire is certified to carry.
Speed Rating: The maximum speed that a
tire is certified to carry a load. Speed ratings
range from “A” to “Z”.
Tire markingsAn example of the meaning of the different
markings in a tire size is given below for a
tire size of 225/45 R17 94H:
225 Tire section width, mm
45 Aspect ratio, i.e. the section height
as a percentage of the section
width
R Radial ply
17 Wheel rim diameter 17 in at bead
seats
94 Tire load index
H Speed rating
Tire load indices
91 Tire approved for max. 1355 lbs.
(615 kg)
93 Max. 1433 lbs. (650 kg)
94 Max. 1477 lbs. (670 kg)
95 Max. 1521 lbs. (690 kg)
97 Max. 1609 lbs. (730 kg)Speed ratings
Q Tire approved for speeds up to
100 mph (160 km/h)
S Max. 112 mph (180 km/h)
T Max. 118 mph (190 km/h)
H Max. 130 mph (210 km/h)
V Max. 149 mph (240 km/h)
W Max. 168 mph (270 km/h)
Y Max. 186 mph (300 km/h)
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254 Car careWinter tiresWinter (snow) tires are recommended for
winter climates where the majority of your
driving will be done on snow and ice. Winter
tires should be fitted to all four wheels to
maintain a proper balance. Your Saab
dealer can advise you of to the correct size
tire for your car (if different from the original
size) and also supply Saab approved winter
tires pre-mounted on steel or alloy rims.
Winter tires normally use a different speed
rating compared to summer/all season tires.
Make sure not to exceed the stated speed
rating on the tires you use.Tire date codeTires should be regarded as perishable
goods. As the tires age, the rubber becomes
progressively harder, and the roadholding
ability of the tires diminishes. This is partic-
ularly true on winter tires.
Tires have a code that specifies their date of
manufacture. The first two digits denote the
week number and the last two digits the year
followed by a filled triangle.
Compact spareThe compact spare is light and easy to
handle when changing the tire. Its use is
only permitted when a standard tire has sus-
tained a puncture. The maximum life of the
tire is only just over 2,000 miles (3,500 km).
Do not exceed 50 mph (80 km/h) with the
compact spare fitted.
The tire pressure should be 60 psi
(420 kPa). Put the punctured tire in the
spare wheel well under the trunk floor.
Have the standard tire repaired and refitted
as soon as possible.The spare tire, the tools and the jack with its
crank are carried under a panel in the trunk.
Fold the carpeting forward to ease access to
the tools and spare tire.
The screwdriver handle has a “button” for
removing plastic rivets. This type of rivet
must be removed when changing the light
bulb in the trunk lid (see page 228).
Your Saab is equipped with a trip computer
and you can use its “Speed warning” func-
tion, to monitor driving speed since you
must not exceed 50 mph (80 km/h), see
page 90.
WARNING
The spare tire or punctured tire must be
stowed under the trunk floor, and secured
in place with the retaining nut.
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255 Car care
Driving with a compact wheel
fittedObserve the following when the compact
spare tire is fitted:
The compact spare is light and easy to
handle when changing a tire.
Do not drive further than necessary with
the compact spare fitted - the maximum life of the tire is only just over 2,000 miles
(approx. 3,500 km).
Refit the standard tire as soon as possi-
ble.
Important considerations when driving with
a compact spare tire:
The car’s ground clearance is reduced.
The car must not be driven with more than
one compact spare tire at a time.
Avoid driving against the curb.
Do not use snow chains.
Do not fit the wheel cover - this would
conceal the warning text.
WARNING
Do not exceed 50 mph (80 km/h). The
tire can overheat affecting the car’s
roadholding.
Tire pressure: refer to page 290.
The spare tire or punctured tire must
be stowed under the trunk floor, and
secured in place with the retaining nut.
NOTICETo avoid damaging a alloy wheel of a
punctured tire, this can be temporarily
placed outside up in the spare wheel well
but only while driving to the closest work-
shop.
As a general rule, all heavy loads must be
well secured in the trunk (see page 139).Tools under a panel in the trunk
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257 Car care
Changing a tire
WARNING
Lifting a vehicle and getting under it to do
maintenance or repairs is dangerous
without the appropriate safety equipment
and training. The jack provided with your
vehicle is designed only for changing a
flat tire. If it is used for anything else, you
or others could be badly injured or killed if
the vehicle slips off the jack. Use the jack
provided with your vehicle only for chang-
ing a flat tire.
Changing a tire can be dangerous. The
vehicle can slip off the jack and roll over
or fall on you or other people. You and
they could be badly injured or even killed.
Find a level place to change your tire. To
help prevent the vehicle from moving:
1 Set the parking brake firmly.
2 If you have an automatic transmis-
sion, put the shift lever in PARK (P).
For a manual transmission, leave the
car in gear (1st or REVERSE (R)).
3 Turn off the engine and do not restart
while the vehicle is raised.
4 Do not allow passengers to remain in
the vehicle.
To be even more certain the vehicle won't
move, you should put blocks at the front
and rear of the tire farthest away from the
one being changed. That would be the
tire, on the other side, at the opposite end
of the vehicle.
The car jack is designed solely for use
in changing a tire or fitting snow
chains. It must not be used to
support the car during repair work
or servicing.
Never crawl under a car that is
supported only by a jack. Always use
axle stands.
Raising your vehicle too high or with
the jack improperly positioned can
damage the vehicle and even make
the vehicle fall. To help avoid personal
injury and vehicle damage, be sure to
fit the jack lift head into the proper
location before raising the vehicle, and
raise the vehicle only far enough off
the ground so there is enough room for
the spare tire to fit (no more than
25 mm or 1 inch clearance between
the ground and the bottom of the tire).
Switch on the hazard warning lights if
the car is on a road.
The jack should be stored correctly
under the carpeting in the trunk. If it
lies loose in the car, it could thrown
forward and cause personal injury in
the event of a crash or if the car rolls
over.
Grit, salt and rust can clog the inner
threads of the wheel bolts if the car has
been driven for several years exclu-
sively with alloy wheels.
If steel wheels are being installed, the
bolt hole threads in the brake hubs
should be cleaned before the thinner
steel wheels are fitted. It may other-
wise not be possible to achieve the
correct clamping force, despite tight-
ening the wheel bolts to the correct
torque.
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