wheel LEXUS SC300 1999 Repair Manual

CHASSIS
367
Uniform tire quality grading
This information has been prepared in accordance with
regulations issued by the National Highway T raffic Safety
Administration of the U.S. Department of
Transportation. It provides the purchasers and/or
prospective purchasers of Lexus vehicles with
information on uniform tire quality grading.
Your Lexus dealer will help answer any questions you may
have as you read this information.
DOT quality grades ± All passenger vehicle tires must
conform to Federal Safety Requirements in addition to
these grades. These quality grades are molded on the
sidewall. Treadwear
± 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 ± 1/2)
times as well on the government course as a tire graded 100.
The relative performance of tires depends upon the actual
conditions of th eir use, however, and may depart significantly
from the norm due to variations in driving habits, service
practices 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, and they represent the tire's
ability to stop on wet pavement as measured under controlled
conditions on specified government test surfaces of asphalt
and concrete. A tire marked C may have poor traction
performance.
Warning: The traction grade assigned to this tire is based on
braking (straight ahead) traction tests and does not include
cornering (turning) traction.
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 dissipate 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
temperature can lead to sudden tire failure. The grade C
corresponds to a level of performance 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

CHASSIS
368required by law. Warning: The temperature grade of this tire 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.
Tire selection
When replacing a tire, use only the same size and
construction as originally installed and with the same or
greater load capacity.
Using any other size or type of tire may seriously affect
handling, ride, speedometer/odometer calibration, ground
clearance, and clearance between the body and tires or snow
chains.
Do not mix radial, belted, or conventional tires on your
vehicle.
Do not use tires or wheels other than the manufacturer's
recommended size.
It can cause dangerous handling characteristics, resulting in
loss of control. If you need to change from conventional tires
to radial tires or vice versa, replace them as a set.

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369
INSTALLING SNOW TIRES ANDCHAINS
When to use snow tires or chains
Snow tires or chains are recommended when driving on
snow or ice.
On wet or dry road, conventional or radial tires provide better
traction than snow or studded tires.
Snow tire selection
If you need snow tires, select the same size, construction
and load capacity as the original tires on your Lexus.
Do not use tires other than stated above. Since your vehicle
has radial tires as original equipment, make sure your snow
tires also have radial construction. Do not install studded tires
without first checking local regulations for possible
restrictions.
Snow tire installation
Snow tires should be installed on all wheels.
Installing snow tires on the rear wheels only can lead to an
excessive difference in road grip capability between the front
and rear tires which could cause loss of vehicle control.

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371
CAUTION
Do not exceed 50 km/h (30 mph) or the chain
manufacturer's recommended speed limit, whichever is
lower.
 Drive carefully avoiding bumps, holes, and sharp turns,
which may cause the vehicle to bounce.
 Avoid sharp turns or locked±wheel braking, as use of
chains may adversely affect vehicle handling.

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372
REPLACING WHEELS
When to replace your wheels
If you have wheel damage such as bending, cracks or
heavy corrosion, the wheel should be replaced.
If you fail to replace damaged wheels, a tire may slip off a
wheel or they may cause loss of handling control.
Replacement with used wheels is not recommended as they
may have been subjected to rough treatment or high mileage
and could fail without warning. Also, bent wheels which have
been straightened may have hidden structural damage and
therefore should not be used. Never use an inner tube in a
leaking wheel which is designed for a tubeless tire.
Wheel selection
When replacing wheels, care should be taken to ensure
that they are equivalent to those rem oved in load capacity,
diameter, rim width, and offset.
Correct replacement wheels are available at your Lexus
dealer.
A wheel of a different size or type may adversely affect
handling, wheel and bearing life, brake cooling,
speedometer/odometer calibration, stopping ability,
headlight aim, bumper height, vehicle ground clearance, and
tire or snow chain clearance to the body and chassis.
ALUMINUM WHEEL PRECAUTIONS
After driving your vehicle the first 1600 km (1000 miles),
check that the wheel nuts are tight.
 If you have rotated, repaired, or changed your tires, check
that the wheel nuts are still tight after driving 1600 km
(1000 miles).
 When using tire chains, be careful not to damage the
aluminum wheels.
 Use only the Lexus wheel nuts and wrench designed for
your aluminum wheels.
 When balancing your wheels, use only Lexus balance
weights or equivalent and a plastic or rubber hammer.
 As with any wheel, periodically check your aluminum
wheels for damage. If damaged, replace immediately.

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405
SPECIFICATIONS
± DIMENSIONS AND WEIGHTOverall length
Overall width
Overall height
Wheelbase
Tread ± Front ± Rear
Vehicle capacity weight (occupants + luggage)
4900 mm (192.9 in.) / 4890 mm (192.5 in.)*1
1800 mm (70.9 in.)
1350 mm (53.1 in.)*2
2690 mm (105.9 in.)
1520 mm (59.8 in.)
1525 mm (60.0 in.)
340 kg (750 lb.)
*1: without front license plate moulding *2: Unladen vehicle
± FUEL TANK
Capacity
78 L (20.6 gal., 17.2 lmp.gal.)

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406
PROTECTING YOUR VEHICLEFROM CORROSION
Proper care of your Lexus can help ensure long±term
corrosion prevention.
The most common causes of corrosion to your vehicle are:

The accumulation of road salt, dirt and moisture in
hard±to±reach areas under the vehicle.

Chipping of paint or undercoating caused by minor
accidents or by stones and gravel.
The following conditions will cause or accelerate
corrosion of your vehicle, so it is important to keep your
vehicle, particularly the underside, as clean as possible
and to repair any damage to paint or protective coatings
as soon as possible.

The presence of road salt or dust control chemicals, salt in
the air near the sea coast, industrial air pollution.

High humidity, especially at temperatures just above
freezing point.

Certain parts of your vehicle are wet or damp for an
extended period of time, even though other parts of the
vehicle are dry.

Components of the vehicle which are prevented from
quick±drying due to lack of proper ventilation are exposed
to high temperature. To help prevent corrosion on your Lexus, follow these
guidelines:
Keep your vehicle clean by regular washing.
In addition,
observe the following points.

If you drive on salted roads in the winter or if you live near
the ocean, you should hose off the undercarriage at least
once a month to minimize corrosion.

High pressure water or steam is effective for cleaning the
vehicle's underside and wheel housings. Pay particular
attention to these areas as it is difficult to see all the mud
and dirt. It will do more harm than good to simply wet the
mud and debris without removing them. The lower edge
of doors, rocker panels and frame members have drain
holes which should not be allowed to clog with dirt as
trapped water in these areas can cause corrosion.

Wash the underside of the vehicle thoroughly when winter
is over.
See ºWashing and waxingº for more tips.
Check the condition of your vehicle's paint and trim. If
you find any chips or scratches in the paint, touch them up
immediately to prevent corrosion from starting. If the chips
or scratches have gone through the bare metal, have a
qualified body shop make the repair.

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407
Check the interior of your vehicle.
Water and dirt can
accumulate under the floor mats and could cause corrosion.
Occasionally check under the mats to make sure the area is
dry. Be particularly careful when transporting chemicals,
cleansers, fertilizers, salt, etc. These should be transported in
proper containers. If a spill or leak should occur, immediately
clean and dry the area.
Use mud shields on your wheels. If you drive on salted or
gravel roads, mud shields help protect your vehicle. Full size
shields, which come near to the ground as possible, are the
best. We recommend that the fittings and the area where the
shields are installed be treated to resist corrosion. Your Lexus
dealer will be happy to assist in supplying and installing the
shields if they are recommended for your area.
Keep your vehicle in a well ventilated garage or a roofed
place. Do not park your vehicle in a damp, poorly
ventilated garage. If you wash your vehicle in the garage,
or if you drive it in covered with water or snow, your garage
may be so damp it will cause corrosion. Even if your garage
is heated, a wet vehicle can corrode if the ventilation is poor.
WASHING AND WAXING
Washing your Lexus
Keep your vehicle clean by regular washing.
The following cases may cause weakness to the paint or
corrosion to the body and parts. Wash your vehicle as soon
as possible.

When driving in a coastal area

When driving on a road sprinkled with antifreeze

When having stuck of coal tar, tree sap, bird droppings and
carcass of an insect

When driving in the areas where there is a lot of smoke,
soot, dust, iron dust and chemical substance

When the vehicle becomes remarkably dirty with dust and
mud
Hand±washing your Lexus
Work in the shade and wait until the vehicle body is not hot
to the touch.
1. Rinse off loose dirt with a hose. Remove any mud or road
salt from the underside of the vehicle or in the wheel wells.
2. Wash with a mild car±wash soap, mixed according to the
manufacturer 's instructions. Use a soft cotton mitt and keep
it wet by dipping it frequently into the wash water. Do not rub
hard ± let the soap and water remove the dirt.

BODY
408Aluminum wheels:
Use only a mild soap or neutral
detergent.
Urethane bumpers and side moldings: Wash carefully. Do
not scrub with abrasive cleaners. The bumper and side
molding faces are soft.
Road tar: Remove with turpentine or cleaners that are
marked safe for painted surfaces.
NOTICE
Do not use gasoline or strong solvents, which may be
toxic or cause damage.
3. Rinse thoroughly ± dried soap can cause streaking. In hot
weather you may need to rinse each section right after you
wash it.
4. To prevent water spots, dry the vehicle using a clean soft
cotton towel. Do not rub or press hard ± you might scratch the
paint.
Automatic car wash
NOTICE
To prevent damage to the antenna, make sure it is
retracted before driving your vehicle through an
automatic car wash.
Your vehicle may be washed in an automatic car wash, but
remember that the paint can be scratched by some type of
brushes, unfiltered washing water, or the washing process
itself. Scratching reduces paint durability and gloss,
especially on darker colors. The manager of the car wash
should be able to advise you whether the process is safe for
the paint on your vehicle.
Waxing your Lexus
Polishing and waxing is recommended to maintain the
original beauty of your Lexus' finish.
Once a month or if the vehicle does not repel water well, apply
wax.
1. Always wash and dry the vehicle before you begin waxing,
even if you are using a combined cleaner and wax.
2. Use a good quality polish and wax. If the finish has
become extremely weathered, use a car±cleaning polish,
followed by a separate wax. Carefully follow the
manufacturer's instructions and precautions. Be sure to
polish and wax the chrome trim as well as the paint.
3. Wax the vehicle again when water does not bead but
remains on the surface in large patches.