SECTION 10 - WHEELS AND TYRES
CAUTION:
This vehicle will be equipped with a Supplemental Restraint System (SRS). A SRS will consist of either
seat belt pre-tensioners and a driver’s air bag, seat belt pre-tensioners and driver’s and front
passenger’s air bags or seat belt pre-tensioners, driver’s and front passenger’s air bags and left and
right-hand side air bags. Refer to SAFETY PRECAUTIONS, Section 12M Supplemental Restraint System
in the VT Series I Service Information before performing any service operation on, or around any SRS
components, the steering mechanism or wiring. Failure to follow the SAFETY PRECAUTIONS could
result in SRS deployment, resulting in possible personal injury or unnecessary SRS system repairs.
CAUTION:
This vehicle may be equipped with LPG (Liquefied Petroleum Gas). In the interests of safety, the LPG
fuel system should be isolated by turning 'OFF' the manual service valve and then draining the LPG
service lines, before any service work is carried out on the vehicle. Refer to the LPG leaflet included with
the Owner's Handbook for details or the appropriate Section of this Service Information CD for more
specific servicing information.
1. GENERAL INFORMATION
New wheels and wheel covers have been introduced for VT Series II vehicles.
The Executive and Acclaim models feature 6.0J × 15 steel wheels and revised wheel covers fitted with either
P205/65 R15 95H tubeless tyres for V6 engines, or 225/60 R15 96V tubeless tyres for GEN III V8 engines.
The Berlina models f eatur e 6.0J × 15 alloy wheels fitted with either P205/65 R15 95H tubeless tyres for V6 engines,
or 225/60 R15 96V tubeless tyres for GEN III V8 engines.
The Calais models feature 7.0J × 16 alloy wheels with 225/55 R16 95V tubeless tyres f or vehicles f itted with either a
V6 engine or a GEN III V8 engine.
The S models use 7.0J × 16 alloy wheels w ith 225/50 R16 92V tubeless tyres.
The SS models use 8.0J × 17 alloy wheels w ith 235/45 R17 93V tubeless tyres.
Techline
Fig. 10-1 illustrates the wheel (1) and wheel
cover (2) cap (3) for Executive and Fleet pack
models.
T210001
21
3
Figure 10-1
Fig. 10-2 illustrates the wheel (1) and wheel
cover (2) fitted on Acclaim models.
T210002
21
Figure 10-2
Fig. 10-3 illustrates the road wheel (1) and wheel
cap (2) fitted on Berlina models.
T210003
2
1
Figure 10-3
Wheel and tyre sizes, inflation pressures and load
capacity are specified on a tyre placard (1) located
on the end surface of the right-hand front door (2),
as shown.
Correct sizes and pressures are the subject of an
Australian Design Rule (ADR) and must be
observed at all times.
T210007
1
2
Figure 10-7
Fig. 10-8 illustrates tyre placard for Executive,
Acclaim and Berlina sedans and (non-LPG)
wagons.
T210023
Figure 10-8
Fig. 10-9 illustrates tyre placard for Executive,
Acclaim and Berlina wagons equipped with LPG.
T210024
Figure 10-9
Fig. 10-10 illustrates tyre placard for Executive,
Acclaim and Berlina sedans and (non-LPG)
wagons fitted with GEN III V8 engine.
T210025
Figure 10-10
Fig. 10-11 illustrates tyre placard for Calais models.
T210027
Figure 10-11
Fig. 10-12 illustrates tyre placard for S pack
models.
T210028
Figure 10-12
Fig. 10-13 illustrates tyre placard for SS pack
models.
T210026
Figure 10-13
All models are equipped with a spare wheel/tyre
assembly and tools necessary for a wheel change,
refer to Fig. 10-14 and Fig. 10-15 for sedan and
station wagon respectively.
T210009
1
2
3
4
Figure 10-14
1. Jack 3. Stowage Compartment
2. Jack/Wheel Nut Wrench 4. Spare Wheel Retaining Bolt and Plate
T210008
3
4
2
1
Figure 10-15
1. Jack 3. Stowage Compartment
2. Jack/Wheel Nut Wrench 4. Spare Wheel Retaining Bolt and Plate
2. SERVICE OPERATIONS
2.1 REPLACEMENT OF WHEELS AND TYRES
W heels mus t be replaced if they are bent, dented or have exc essive lateral or radial run-out. Wheels with greater
than specified run-out may cause objectionable vibration through the vehicle.
Replacement wheels must be equivalent to the original equipment wheels in load capacity, diameter, rim width,
profile, offset and mounting configuration. A wheel of incorrect size or type may affect wheel and bearing life,
brake cooling, speedometer/odometer calibration, vehicle to ground clearance or tyre to body or chassis
clearance.
The selection of replacement tyres requires careful consideration if vehicle handling, braking, steering response
and ride comfort are to be preserved.
In the course of vehicle development, all of the factors influencing handling and ride comfort are considered and
particular emphasis is placed on the role of tyres in order to achieve optimum standards in vehicle performance.
W hen selecting replacem ent tyres , cons ult the tyr e placard to determ ine appropriate tyre sizes. It is ess ential that
replacements be of the same size, type and speed/load rating in order to maintain intended ride, handling and
braking. This also ensures compatibility of new tyres with existing tyres and the spare tyre.
NOTE: Do not mix diff erent types of tyres on the same vehicle except in emergencies, because vehicle handling
may be seriously affected and may result in loss of control.
It is recom mended that new tyres be installed in pairs on the same axle. If necessary to replace only one tyre, it
should be paired with the tyre having the most tread, to equalise braking traction.
TYRE MARKINGS
The tyre sidewall has a coded marking system
which gives various information about the tyre.
NOTE: The effective load capacity for the rear tyres
fitted to VT Series II models, is 95% of specified
load capacity due to the effect of the rear
suspension negative camber.
Tyre Marking Example:
P 205 65 R 15 92 H
P= Pass enger Tyre Type
205 = Secti on Width (1) - mm (205 mm)
65 = Aspec t Ratio % (Secti on Hei ght (2) to Sec tion
Width (1) (65 = 65%)
R= Tyre Construction (R = Radial)
15 = Rim Di ameter - inches (15 = 15”)
92 = Load Index - kg (92 = 630 kg m ax. load)
(93 = 650 kg m ax. load)
(94 = 670 kg m ax. load)
(95 = 690 kg m ax. load)
(96 = 710 kg m ax. load)
H= Speed Rating (H = 210 km /h)
(V = 240 km/h)
1
2
T210010
Figure 10-16
2.2 TYRE INFLATION AND INSPECTION
The pressure recommended for any model is carefully calculated to give satisfactory ride, stability, steering, tread
wear, tyre life and resistance to wheel/tyre damage.
Tyre pressures, with COLD tyres (after vehicle has s tood for three hours or more, or dr iven less than 2 kilom etres)
should be checked weekly or before any extended trip, and set to the specifications on the tyre placard located on
the end surface of the right-hand front door, as shown in Fig. 10-7.
When checking tyre pressure, visually inspect tyres for excessive wear, sharp objects embedded in the tyre or
damage to sidewalls.
NOTE 1: Clean valve exterior, prior to applying air pressure nozzle when inflating ty re.
NOTE 2: Always reinstall valve caps to keep out dust and water.
PRESSURE ADJUSTMENTS TO SUIT OPERATING CONDITIONS
For continuous high speed operation, increase pressures as recommended on the tyre placard.
Tyre pressure can increase as much as 40 kPa when hot. DO NOT REDUCE PRESSURES TO OFFSET THIS
BUILD UP.
For operation on unsealed rough roads, increase COLD tyre pressures 28 kPa above that shown on the tyre
placard.
NOTE: Tyre pressures are not to be increased for unsealed rough road condition if tyre pressures have already
been increased for high speed operation.
2.3 WHEEL REMOVAL AND INSTALLATION
IMPORTANT: Before removing any wheel, mark
the relationship of the wheel to the mounting flange
or brake disc/hub.
Difficulty in wheel removal can be caused by either
corrosion or a tight fit between the wheel centre
and the mounting or brake disc/hub flange.
NOTE: If tightness is caused by corrosion, do not
use heat or heavy impact.
If a wheel is tight, proceed as follows;
1. Tighten and loosen each road wheel attaching
nut a maximum of two turns.
2. Lower vehicle to ground and allow weight of
the vehicle to rest on the wheel.
3. Drive the vehicle approximately 2 metres in a
forward and reverse direction. Apply quick,
hard jabs on the brake pedal to loosen the
wheel.
4. Raise the vehicle and remove road wheel
attaching nuts and remove wheel.
Should a removed road wheel show signs of
corrosion, then all deposits should be removed
from the hub spigot and mating bore of the alloy
wheel, using fine emery paper.
Wash down with mineral spirit, dry and apply a light
coating of a lubricant such as Omega 929 or
equivalent to the hub spigot, using a small brush.
Remove any excess with mineral spirit and allow
the product to dry before installing the road wheel.
NOTE: Installing wheels without good metal to
metal contact at the mounting surfaces can result
in wheel nuts coming loose.
Tighten road wheel attaching nuts to the specified
torque and in the order shown.
NOTE: Do not use an impact gun to tighten wheel
nuts unless it is fitted with a torque limiter bar
(commercially available). Failure to correctly tighten
wheel nuts to the correct torque specification may
result in a warped brake disc, which may lead to
development of brake shudder.
T210011
5
3
4
1
2
Figure 10-17
ROAD WHEEL
ATTACHING NUT
TORQUE SPECIFICATION 110 – 140 Nm
2.4 TYRE ROTATION
For VT Series II models, it is recommended that
tyre rotation be carried out when brake inspections
are performed, as per the s ervic e sc hedule outlined
in the Owner's Handbook, or when:
1. Difference in tread depth between front and
rear tyres is 1.5 mm.
2. When any unusual tyre wear pattern develops.
If uneven tyre wear is evident, the reason for it
should be corrected if at all possible.
If the tyres are rotated, it is recommended that the
tyre and wheel assembly balance be checked at
the same time, refer to
2.8 WHEEL AND TYRE BALANCING in this
Section.
Tyre rotation in accordance with Fig. 10-18 will
assist in obtaining maximum tyre life.
T210012
Figure 10-18
2.5 CHECKING TYRE/WHEEL ASSEMBLY RUN-OUT
Because the run-out of a tyre/wheel assembly will
directly affect the amount of imbalance and radial
force variation, it should be corrected first. The
smaller the amount of run-out, the less imbalance
and force variation. Radial and lateral run-out can
be corrected at the same time. There are two
methods to measure run-out of the tyre/wheel
assemblies:
♦ On the vehicle (mounted to the hub - wheel
bearing must be in good condition)
♦ Off the vehicle (mounted on a spin-type wheel
balancer).
NOTE: Initial on-car inspection should be made
prior to off-car run-out checks.
Measuring the tyre/wheel run-out off the vehicle is
easiest. It is usually easier to m ount a dial indicator
in the correct location, and the chances of water,
dirt, or slush getting on the dial indicator are
decreased. Once the run-out has been measured
and corrected off the vehicle, a quick visual check
of run-out on the vehicle will indicate if any further
problems exist.
If there is a large difference in the run-out
measurements from on-vehicle to off-vehicle, then
the run-out problem is due to either stud pattern
run-out, hub f lange run-out, or a m ounting problem
between the wheel and the vehicle.
Before measuring or attempting to correct
excessive run-out, carefully check the tyre for an
uneven bead seat. The distance from the edge of
the ring to the concentric rim locating ring should
be equal around the entire circumference. If the
beads are not seated properly, the tyre should be
remounted. Otherwise, excessive run-out and
imbalance will result.
IMPORTANT: If the vehicle has been sitting in one
place for a long time, flat spots may exist at the
point where the tyres were resting on the ground.
Thes e flat spots will affect the r un-out readings and
should be eliminated by driving the vehicle long
enough to warm up the tyres prior to conducting
any run-out measurements.
PROCEDURE
1. Lift the vehicle on a hoist or s upport with jack-
stands.
2. In order to get an initial indication of how much
run-out exists, spin each tyre and wheel on the
vehicle by hand (or at a slow speed using the
engine to run the drive wheels). Visually check
the amount of run-out from the front or rear.
3. Mark the location of each tyre/wheel assem bly
in relation to the wheel studs and to their
position on the vehicle (eg. r ight fr ont, lef t r ear)
for future reference.
4. Remove tyre/wheel assemblies one at a time
and mount on a spin-type wheel balancer.
5. Measure the tyre/wheel assembly radial (3)
and lateral run-outs (1), using a dial indicator
fitted with a roller.
NOTE 1: With tyres that use an aggressive tread
pattern, it will be necessary to wrap the outer
circumference with tape (2) when measuring radial
run-out, to provide a smooth surface for a more
accurate measurement.
NOTE 2: Lateral run-out should be measured on a
smooth area of the sidewall, as close to the tread
as possible. Any jumps or dips due to sidewall
splices should be ignored and an average amount
of run-out attained.
1. Slowly rotate the assembly one complete
revolution and zero the dial indicator on the
low spot.
2. Rotate the assembly one more complete
revolution and note the total amount of r un-out
indicated.
As a guide, the tyre/wheel assembly, radial and
lateral run-out should be no more than 1.5 mm
when measured off the vehicle.
T210013
121
3
Figure 10-19
MATCH MOUNTING
NOTE: While this operation is not normally
necessary with original equipment tyres, when
replaced, match mounting is recommended to
obtain optimum vehicle handling and performance.
If tyre/wheel assembly run-out is excessive, mark
the location of the high and low spot on the tyre
and the wheel. The next s tep will be to deter m ine if
the run-out problem exists in the tyre, wheel, or a
combination of both, then to correct it. The
procedure us ed to accom plish this is called m atch-
mounting or system matching.
1. Place a mark on the tyre sidewall (1) at the
location of the valve stem (3). This will be
referred to as the 12:00 o’clock position. The
location of the high spot A will always be
referred to in relation to its clock position on
the wheel.
2. Mount the tyre wheel assembly on a tyre
machine and break down the bead. Do not
dismount the tyre from the wheel at this time.
3. Rotate the tyre 180° on the rim so the valve
stem referenc e m ark (2) is now at 6:00 o’clock
in relation to the valve stem itself. Inflate the
tyre and make sure the bead is seated
properly. You may have to lube the bead to
easily rotate the tyre on the wheel.
4. Install the assembly on the tyre balancer and
again measure the run-out. Mark the new
location of the run-out high spot B on the tyre.
If the run-out is now within tolerance, no further
steps are necessary. The tyre may be balanced
and installed on the vehicle.
Alternatively, if the clock location of the high spot B
remained at or near the clock location of the
original high spot A (as in Fig. 10-20), the wheel is
the major contributor to the run-out problem. It
should be measured for excessive run-out, as
detailed in 2.6 CHECKING WHEEL RUN-OUT and
replaced if found to exceed specification.
If the high spot is now at or near a position 180°
(6.00 o’clock ) from the original high spot, the tyre is
the major contributor (as in Fig. 10-21) and should
be replaced.
Always remeasur e the tyre/wheel assembly run-out
after replacing the tyre and make sure the run-out
is within tolerance befor e continuing. In the m ajority
of cases, the first 180° rotation of the tyre will either
correct the run-out problem or indicate which
component to replace.
If the high spot is between the two extremes, then
both the tyre and wheel are contributing to the run-
out. Try rotating the tyre an additional 90° in both
the clockwise (9.00 o’clock) and anti-clockwise (3
o’clock) directions, measuring the run-out after
each rotation.
If run-out cannot be corrected by match-mounting,
then the tyre must be removed and the wheel run-
out measured, as detailed in the next Operation.
Once run-out has been brought within the
tolerance, the tyre/wheel assembly should be
balanced.
T210014
2
3
B
A
1
Figure 10-20
T210015
2
B
3
A
1
Figure 10-21
2.6 CHECKING WHEEL RUN-OUT
Wheel run-out should be measured on the inside
bead area of the wheel. Measure the run-out in the
same fashion as tyre run-out. Ignore any jumps or
dips due to paint drips, chips, or welds, measure
both inboard and outboard
If the run-out of the wheel is within tolerance, and
the tyre/wheel assembly run-out cannot be reduced
to an acceptable level by using the match-mounting
technique, the tyre must be replaced. Always
measure assembly run-out after replacing the
tyre.
If there is a large difference in the run-out
measurements from on-vehicle to off-vehicle, then
the run-out problem is due to either stud pattern
run-out, hub flange run-out, or a mounting problem
between the wheel and the vehicle.
The tolerances listed are to serve as guidelines.
If run-out measurements are within tolerance but
are marginal, some sensitive vehicles may still be
affected. It is always advisable to reduce run-out to
as little as possible in order to attain optimum
results under all conditions.
PROCEDURE
NOTE: This measuring procedure can be used
equally well on either steel or alloy road wheels.
1. Raise vehicle and support on safety stands.
2. Remove wheel cover (steel wheels) or centre
cap (alloy wheels).
3. Mark relationship of wheel to mounting flange
or brake disc/hub. Remove wheel attaching
nuts and remove wheel.
4. Mark relationship of tyre to wheel rim and then
remove tyre from rim.
5. Check that the wheel and mounting flange or
brake disc/hub mating surfaces are clean and
free from burrs.
6. Install the wheel onto the mounting flange or
brake disc/hub and install wheel attaching
nuts. Tighten nuts to the correct torque
specification.
ROAD WHEEL
ATTACHING NUT
TORQUE SPECIFICATION 110 – 140 Nm
7. Using a dial indicator with a roller fitted to the
probe, secure the base to a fixed point. Then,
slowly rotate the road wheel and measure
wheel run-out at the points shown.
1 = Lateral Run-out.
2 = Radial Run-out.
Wheel run-out should be within the specified
values listed in 4. SPECIFICATIONS in this
Section.
If not within specification, replace wheel.
NOTE: Always m easure the run-out of new wheels
when replacing old ones. Do not assume that a
new wheel is automatically a known good
component.
T210016
1
2
Figure 10-22
2.7 TYRE REMOVAL AND INSTALLATION
Whenever possible, tyre removal and installation
should be carried out on a tyre changing machine.
The use of tyre levers and mallets is likely to
damage tyre carcasses and wheel rims.
Minor dents and burrs on steel rims can be
repaired by filing, but alloy rims must always be
replaced if significantly damaged.
CAUTION: Wheels must not be welded, brazed,
peened or treated in any manner which could
weaken them.
The bead seat of the rim must be clean and
smooth; rust, rubber etc. may be removed with a
wire brush or steel wool.
Before removing or installing a tyre, or installing a
valve stem, apply tyre lubricant (Holden's
Specification HN1162) to the tyre bead and rim
flanges.
Install valve stem and tyre before lubricant dries.
Initially, inflate tyre to 280 kPa to ensure that the
tyre beads seat correctly in the rim flanges.
If the tyre beads fail to seal at this press ure, def late
the tyre, lubricate the tyre beads and wheel rim
again and then inflate.
CAUTION: Exercise care to avoid personal
injury when the tyre bead snaps ov er the wheel
rim safety humps.
NOTE: When fitting a tyre to a rim, it is important to
ensure that the tyre is correctly indexed to the rim,
i.e. the first harmonic high point of the tyre should
be fitted so that it is matching the f ir st har monic low
point of the rim. This matching minimises force
variations inherent with tyre and rim manufacture.
(Refer to 3. DIAGNOSIS in this Section for more
information on harmonics.)
As different origins of tyres have different standards
regarding the first harmonic point, refer to the
following as a guide to the correct tyre fitting
position.
♦ Australian manufactured tyres have a red dot
indicating the first harmonic high point.
♦ European manufactured ty res have a white dot
indicating the first harmonic low point.
♦ Some Japanese manufactured tyres have a
red dot indicating the first harmonic high point
and a yellow dot (which should be ignored)
which indicates a static balance point.
As independent rear suspension vehicles are m ore
sensitive to a wheel/tyre imbalance condition than
other suspension designs, particular care should be
given to correct fitment of tyres to all VT vehicles.
TYRE REPAIRS
There are many different materials and techniques
available to repair tyres. It is suggested that details of
mater ials and proc edures f or the repair of tyres should
be obtained from the tyre manufacturer.
JAPANESE MFD. TYRES
If there is a YELLOW dot but not a red dot use the
rule for Australian tyres. If there is a YELLOW and
a RED dot, ignore the yellow dot and use the red
dot as per rule for Australian ty res.
EUROPEAN MFD. TYRES
(White dot on s/wall)
Align WHITE dot on tyre 180° from the mark on
outer flange of wheel, or if there is no mark on the
wheel, align WHITE dot 180° from the low spot of
wheel as measured with dial indicator.
AUSTRALIAN MFD. TYRES
(Red dot on s/wall)
Align RED dot on tyre to mark on outer flange of
wheel, or if there is no mark on the wheel, align
RED dot to low spot of wheel as measured with dial
indicator.
2.8 W HEEL AND TYRE BALANCING
There are two types of wheel and tyre balance;
Static and Dynamic.
STATIC balance is the equal distribution of weight
around the wheel.
Vibrations caused by static imbalance will cause a
vertical or bouncing motion of the tyre.
1 = Direction of Motion of Wheel
2 = Position for Balance Weight
3 = Heavy Point
T210017
22
11
1
33
1
14
R
70
195
-
P
Figure 10-23
DYNAMIC balance aff ects the distribution of weight
on each side of the tyre/wheel centreline.
Dynam ic imbalanc e results in a side-to-s ide motion
of the tyre, sometimes referred to as shimmy.
1 = Direction of Motion of Wheel
2 = Position for Balance Weight
3 = Heavy Point
T210018
2
2
2
2
11
1
33
1
14
R
70
195
-
P
Figure 10-24
OFF-VEHICLE BALANCING
When wheel and tyre assemblies require balancing, they should be removed from the vehicle and balanced on a
machine capable of ensuring correct static and dynamic balance. Balancing should be carried out in accordance
with the machine manufacturer's instructions to obtain the results as outlined under BALANCE LIMITS.
Although hub/brake discs do not contribute significantly to an out of balance condition, it is desirable to fit wheels to
the same position on the vehicle after balancing. Accordingly, it is good practice to mark the relationship of the
wheel to the axle flange or brake hub/disc, prior to wheel removal.
Before balancing, remove all accumulated mud from the wheel and any embedded stones from the tyre treads. If
using on-vehicle balancing equipment, observe the LIMITED SLIP DIFFERENTIAL PRECAUTIONS as outlined in
Section 4B FINAL DRIVE AND DRIVE SHAFTS in the VT Series I Service Information.
ON-VEHICLE BALANCING
If checking and/or correcting a tyre/wheel imbalance condition off the vehicle and it is not possible or does not
correct the vibration, it may be necessary to balance the assembly/ies while mounted on the vehicle, using an on-
vehicle, high-speed spin balancer. This will balance the hubs, rotors, and wheel trims simultaneously. Also, it can
com pens ate f or any amount of r es idual run-out enc ounter ed as a r es ult of mounting the tyre/wheel assem bly on the
vehicle, as opposed to the balance that was achieved on the off-vehicle balance.
Always follow the on-vehicle balancer manufacturer Operator's Manual for specific instructions.
NOTE 1: Do not remove the off-vehicle balance weights. The purpose of on-vehicle balance is to fine tune the
assembly balance already achieved, not to begin again.
NOTE 2: Leave all wheel trim s installed where poss ible. Som e wire wheel covers have been k nown to induc e s tatic
imbalanc e. If you suspect a wheel trim of caus ing the vibration, it can be elim inated by road testing the vehicle with
the wheel trim removed.
NOTE 3: If the on-vehicle balance calls f or mor e than 10 grams of additional weight, split the weight between the
inboard and outboard flanges of the wheel, to avoid disturbing the dynamic balance of the assembly, achieved in the
off-vehicle balance procedure.
NOTE 4: Evaluate the condition following the on-vehicle balance to determine if the vibration has been eliminated.
BALANCE LIMITS
Maximum allowable out of balance is 8 grams per
side of rim.
Total balanc e weights are not to exceed 120 grams
per wheel with a maximum of 80 grams per wheel
flange. If a wheel assembly requires more than
these limits, fit another tyre to the wheel and re-
balance.
NOTE:Specific wheel weights for each design of
wheel are used. This is due to the differences in
wheel rim profile.
The shape of wheel weights are shown in Fig 10-19
sections A and B. Section A shows wheel weight
and profile for steel wheels. W eights of this design
are available in 10 grams and 15 grams.
Section B shows wheel weights and profiles for
alloy wheels. Weights of this des ign are available in
20, 30, 40 and 50 grams.
A third style of wheel weight is ribbon weight (not
illustrated), which has a self-adhesive backing
enabling weights to be adhered to clean flat
surf aces on inside diameter of wheel. T hese ribbon
weights are used primarily on alloy wheels and are
available marked in increments of 5 grams or
10 grams.
T210019
1
1
A
B
Figure 10-25
2.9 WHE EL ATTACHING NUTS/STUDS
Important: When alloy wheels are fitted to VT
Series II vehicles, special attaching wheel nuts (2)
are also used. If VT Series II alloy wheels are to be
fitted to a vehicle normally equipped with steel
wheels, then the original nuts (1) MUST be
discarded and revised design attaching nuts used
on the replacement wheels.
For removal and installation instructions for the
wheel attaching studs (3), either refer to
Section 3 FRONT SUSPENSION or
Section 4B FINAL DRIVE AND DRIVE SHAFTS in
the VT Series I Service Information.
All models use metric (M12 x 1.5) wheel attaching
studs and nuts (refer to A, in Fig. 10-26).
T210020
M
A
A
3
2
18.0
1
60 60
24.0
40.0
Figure 10-26
Techline
3. DIAGNOSIS
3.1 WEAR
Analysis of tyre wear conditions is adequately covered in tyre company literature.
3.2 ROAD TESTING
Because there are many reasons for a vibration condition to be present in a vehicle, it is vital that a thorough road
test be conducted, to eliminate other possible causes for a vibration condition being present.
TYRE AND WHEEL INSPECTION
This visual inspection should be conducted for all vibration com plaints unless the disturbance only occurs with the
vehicle at a standstill.
• The tyres should be inspected for unusual wear, including cupping, flat spots and heel-and-toe wear. These
conditions can cause tyre growl, howl, slapping noises, and vibrations throughout the vehicle.
• Establish that all tyres are inflated to the correct pressures prior to any road test.
• Check for bulge’s in the sidewalls.
• Check all wheels for bent rim flanges. Many times, hub caps or trim rings that appear dented, can indicate a
bent wheel underneath.
SLOW ACCELERATION TEST
This test is to identify engine or vehicle speed related conditions. It will be necessary to perform additional tests in
order to determine in which category the vibration belongs.
1. On a smooth, level road, slowly accelerate up to highway speed.
2. Look for disturbances that match the customer's description.
3. Note the vehicle speed (km/h) and engine speed (rpm) where the disturbance occurs.
Follow this test with the neutral coast-down test, and the downshift test.
NEUTRAL COAST-DOWN TEST
1. On a smooth, level road, accelerate to a speed slightly higher than the speed at which the vibration occurs.
2. Shift the vehicle into NEUT RAL and coast down through the vibration r ange. Note if the vibration is present in
NEUTRAL.
If the vibration still occurs in NEUTRAL, it is definitely vehicle-speed sensitive. At this point, the engine and
torque converter have been eliminated as a cause. Depending on the symptoms or frequency, the repair will
concentrate on either the tyres and wheels or the propshaft and rear axle.
DOWNSHIFT TEST
1. On a smooth, level road, accelerate to the speed at which the complaint vibration occurs. Note the engine rpm.
2. Next, decelerate and safely downshift to the next lower gear (from overdrive to drive, or from drive to second
gear).
3. Operate the vehicle at the previous engine rpm.
If the vibration returns at the same rpm, the engine or torque converter are the most probable causes. To
confirm these results, repeat this test in still lower gears, and in NEUTRAL.
STEERING INPUT TEST
This test is intended to determine how much wheel bearings and other suspension components contribute to a
vibration, especially those relating to noises, howl or growl, grinding and roaring.
• W ith the vehicle at the vibration speed (k m/h), drive through slow, sweeping turns - first in one direction, then
the other.
• If the vibration either gets worse or goes away, the wheel bearings, hubs and tyre tread wear are all possible
causes.
STANDING START ACCELERATION
The purpose of this test is to duplicate a vibration called Take-off-Shudder. In some cases, a powertrain mount or
the exhaust contacting the body may also be suspect, depending on the symptoms.
1. With the vehicle at a complete stop and in gear, remove your foot from the brake.
2. Accelerate to 60 or 70 km/h while checking for vibrations that match the customer's description.
Shudder in the seat or s teering wheel under these conditions usually results f rom im proper dr iveline angles. W o rn,
tight or failed universal joints may also be a cause, and should be inspected first.
Grunting or groaning noises along with a buzzing or roughness in the floor usually points to the vibration being
conducted through the engine or transmission mounts, or through exhaust mounts and hangers that have
GROUNDED OUT. Refer to the respective Sections in this Service Information CD for rectification procedures.
3.3 VIBRATION
To determine the cause of a vibration condition that is suspected of being tyre/wheel related, a key aspect is to
understand the nature of first and second order vibrations (or harmonics).
As shown in Fig. 10-27 Section A, a tyre with one high spot would create a disturbance once every complete
revolution. This is called first-order vibrations.
An oval shaped tyre with two high spots (as shown in Section B) would create a disturbance twice per revolution.
This is called second-order vibrations.
Three high spots would be third order, and so on.
Two first-order vibrations may add to or subtract from the overall amplitude of the disturbance, but that is all. Two
first- order vibrations do not equal a second-order. Due to centrif ugal force, an out- of-balance c omponent (eg. tyres,
drive shafts or engine) will always create a first-order vibration.
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Figure 10-27
If wheel and tyre assem blies are balanced to the degree required and vibration is still evident, then tyre run-out or
Force Variation could be responsible.
RADIAL FORCE VARIATION
Radial force variation refers to a difference in the
stiff nes s of a tyre sidewall as it rotates and contacts
the road. The sidewall when likened to springs (as
in Fig. 10-28) the lighter springs (1) represent a
normal sidewall while the heavier spring (2)
represents a stiffer section of the sidewall
Tyre/wheel assemblies have some of this due to
splices in the different plies of the tyre, but they do
not cause a problem unless the force variation is
excessive. These stiff spots in the sidewall can
deflect the tyre/wheel assembly upward as they
contact the road.
If there is only one stiff spot in the sidewall, it will
deflect the spindle once per each revolution of the
tyre/wheel assembly, causing a first order
tyre/wheel vibration.
If there are two stif f spots , they can cause a sec ond
order vibration.
First and second order tyre/wheel vibrations are the
most common to occur as a result of radial force
variation. Higher orders (eg. third, fourth) are
possible, but quite rare. The most effective way to
minimise the possibility of force variation as a factor
in tyre/wheel vibration is to ensure that the
tyre/wheel assembly run-out is at an absolute
minimum.
Some tyre/wheel assemblies may exhibit vibration
causing amounts of force variation even though
they are within run-out and balance tolerances. Due
to tighter tolerances and higher standards in
manuf acturing, these instances are becoming rare.
If force variation is suspected as being a factor,
substitute one or more known good tyre/wheel
assemblies for the suspect assemblies. If this
rectifies the problem replace the offending tyre.
T210022
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Figure 10-28
LATERAL FORCE VARIATION
This is based on the sam e concept as radial force variation, except that lateral force variation tends to deflect the
vehicle sideways or laterally, as the name implies. It can be caused by a snaky belt inside the tyre. Tyre
replacement using the substitution method may be necessary.
This condition is very rare and again, the best way to eliminate it as a factor is to ensure that the lateral run-out of
the tyre/wheel assemblies is at an absolute minimum.
In most cases where excessive lateral force variation exists, the vehicle will display a wobble or waddle at low
speeds (8 to 40 km/h) on a smooth road surface. The condition will usually be related to a first order vibration of
tyre/wheel rotation.
Tyre run-out will always be present to some degree due to dimensional tolerances in both the tyre and wheel and
can often be reduced by rotating the tyre on the wheel to cancel out the overall effect. The same problem can be
caused by Force Variation which is, in effect, a variation in stiffness around the tyre which results in a varying
loaded radius as the tyre rotates.
All of these factors have so far been considered to act radially. However lateral run-out and lateral force variation
can also be translated into vehicle vibration ranging from low speed waddle to relatively high speed shake or
vibrations sim ilar to thos e obtained with tyre im balance. T he following diagnosis pr ocedure indicates the process of
test and logic required to determine the cause of wheel and tyre induced vibration.
3.4 LEAD
Lead is the deviation of the vehicle from a straight path on a level road (no camber) with no load on the steering
wheel and is usually caused by alignment and brake drag , but can sometimes be caused by tyres.
The way in which a tyre is built can produc e lead in a vehicle. An exam ple of this is placem ent of the belt in a radial
tyre. Off centre belts can cause the tyre to develop a side force while rolling straight down the road.
If one side of the tyre is a little larger in diameter than the other, the tyre will tend to roll up to one side. This will
develop a side for ce which can produce vehicle lead. Bef ore attem pting to f ind a faulty tyre , thoroughly check wheel
alignment, brakes and steering components.
The following diagnostic chart can be used to confirm vehicle lead.
DIAGNOSING VEHICLE LEAD
STEP ACTION YES NO
1• Inflate tyres to the correct pressures.
• Road test vehi cle in opposi te direct i ons, on a level,
uncrowned road with no wind.
• Does vehicle l ead to the same si de i n both direct i ons?
Go to Step 2. Go to Step 8.
2• Swap front tyres f rom one si de to the other and road t est,
again in opposite directi ons.
• Does vehicle l ead to the same si de as in St ep 1?
Put tyres back in ori gi nal positions .
Go to Step 8. Go to Step 3.
3• Does the vehic l e now lead to the opposit e side to that in
Step 1? Go to Step 5. Go to Step 4.
4• Has the lead c ondi tion been correc ted? Leave tyres as i s. If roughness
develops, repl ace front t yres. Go to Step 5.
5• Instal l a known good tyre to replace one f ront tyre and
road test agai n.
• Is the l ead condition corrected?
Lead conditi on has been isolat ed.
Replace tyre. Go to Step 6.
6• Check test tyre on a k nown good vehicl e.
• Has the lead c ondi tion been correc ted? Test tyre i s faulty - replace.
Go to Step 5. Go to Step 7.
7• Instal l a known good tyre to replace remaining front tyre.
• Has the lead c ondi tion been correc ted? Lead conditi on has been isolat ed.
Replace tyre. Go to Step 8.
8• Check/correct vehi cle wheel alignm ent and mal adj usted
or binding st eeri ng.
• Road test agai n. Has the lead condition been corrected?
Vehicl e is now operating to
specification. Swap tyres, f ront to
rear.
Go to Step 4.
4. SPECIFICATIONS
STEEL WHEEL
Rim Width Code...................................................... 6.0J
Diameter Code........................................................ 15
Maximum Permissible Radial Run-out............... 0.6 mm
Maximum Permissible Lateral Run-out.............. 0.8 mm
Offset.................................................................. 43 mm (positive)
ALLOY WHEELS
Rim Width Code...................................................... 6.0J 7.0J 8.0J
Diameter Code........................................................ 15 16 17
Maximum Permissible Radial Run-out
Berlina ............................................................... 0.25 mm
S........................................................................ 0.25 mm
SS ...................................................................... 0.25 mm
Calais ................................................................. 0.25 mm
Maximum Permissible Lateral Run-out
All models........................................................... 0.3 mm
Offset
Berlina ............................................................... 43 mm (pos)
S........................................................................ 43 mm (pos)
SS ...................................................................... 48 mm (pos)
Calais ................................................................. 48 mm (pos)
TYRES
Dynamic Balancing - All
Maximum Permissible Wheel/Tyre Out of Balance 150 g
Maximum Permissible Tyre Radial
1st Harmonic Force Variation (tyre only)............ 65 N
Maximum Load Rating (per tyre) ✸
✸ Refer to 2. SERVICE OPERATIONS — TYRE MARKINGS in this Section.
5. TORQUE WRENCH SPECIFICATIONS
Nm
ROAD WHEEL ATTACHING NUTS
Steel Wheel........................................................................... 110 – 140
Alloy Wheel........................................................................... 110 – 140