Road Wheels and Tyres (04.04)
Suspension (04.00)
May 2007 Workshop Manual 4-4-3
Maintenance
Factory installed tyres and road wheels are designed to
operate satisfactory when inflated to the recommended
inflation pressures (Refer to ’Inspection and Verification’,
page 4-4-4). The recommended pressures apply to vehicle
loads up to and including the full-rated load capacity.
Correct tyre pressures and driving technique have an
important influence on tyre life. Heavy cornering,
excessively rapid acceleration and unnecessary sharp
braking increase tyre wear.
Replacement tyres should follow the recommended:
The use of any other size or type may seriously affect:
Wheels need to be renewed when:
Safety
Tyre Replacement and Wheel
Interchanging
When replacement of tyres is required it is preferable to
install a complete vehicle set. S hould either the front or rear
tyres only show excessive wear, new tyres must be installed
to replace worn ones. Under no circumstances interchange
tyres from side to side, front to re ar or vice versa as individual
tyre wear produces unique characteristics depending upon
their position. If the position is changed after wear has
occurred, the performance of the tyre will be adversely
affected.
New tyres must be balanced before installing to the vehicle.
•Size
•Speed rating
•Load range
• Radial construction type
•Safety
•Ride
•Handling
• Speedometer and Odometer calibration • Vehicle ground clearance
• Tyre clearance between
body and chassis
• Wheel bearing life
• Brake cooling
• Impact damaged
• Heavily corroded
• Porous • Wheel stud holes or seats
become damaged
• They have excessive radial or lateral runout.
ENSURE THAT TYRES ARE MOUNTED WITH THE
SIDEWALL MARKING ‘OUTSIDE’ SHOWING ON THE
OUTER SIDEWALL FACE.
CORRECT TYRE ROTATIONAL DIRECTION IS CRITICAL.
WA R N I N G
A TYRE AND WHEEL MUST ALWAYS BE CORRECTLY MATCHED. WIDER OR NARROWER TYRES THAN
RECOMMENDED COULD CAUSE DANGER THROUGH
SUDDEN DEFLATION.
WA R N I N G
WHEN CHANGING A WHEEL, MAKE SURE THAT THE VEHICLE CANNOT MOVE. ALWAYS APPLY THE
PARKING BRAKE AND SELE CT THE TRANSMISSION
PARK POSITION (AUTOMATIC TRANSMISSION ONLY).
WA R N I N G
NEVER RUN THE ENGINE WITH ONE WHEEL OFF THE GROUND, FOR EXAMPLE, WHEN CHANGING THE
WHEEL. THE WHEEL RESTING ON THE GROUND MAY CAUSE THE VEHICLE TO MOVE.
WA R N I N G
ALWAYS TIGHTEN THE WHEEL NUTS TO
SPECIFICATION. TOO TIGHT MAY CAUSE DAMAGE,
TOO LOOSE MAY ALLOW TH E WHEEL TO BECOME
DETACHED.
WAR NI NG
DO NOT MIX DIFFERENT TY PES OF TYRES ON THE
SAME VEHICLE. HANDLING MAY BE SERIOUSLY AFFECTED RESULTING IN LOSS OF CONTROL.
WAR NI NG
USE ONLY WHEELS AND WHEEL NUTS SUPPLIED BY
ASTON MARTIN. AFTER MARKET WHEELS OR WHEEL
NUTS MAY NOT INSTALL OR FUNCTION CORRECTLY
AND COULD CAUSE INJURY OR DAMAGE.
Caution
When a new tyre is installe d, always renew the tyre
valve.
Road Wheels and Tyres (04.04)
Suspension (04.00)4-4-6 Workshop Manual May 2007
Ty r e D a m a g e
Vehicle vibrations Tyres and wheels mismatched Install correct tyre and wheel combination.
Inflation pressure too high or too lo w Correct pressure to specification
Uneven tyre wear Refer to Diagnosis and Testing .
Out-of-balance wheel, tyre, wheel hub
or disc assembly Determine the out-of-balance component and
balance or install a new part.
Damaged or distorted wheel from road
impact hazard or incorrect handling Install a new wheel.
Excessive radial runout Install a new wheel or tyre. Check for incorrect wheel and tyre specifications.
Excessive lateral runout Install a new wheel or tyre.
Incorrectly seated tyre Remount the tyre.
Loose wheel mountings - damaged
wheel studs, wheel nuts, worn or
broken wheel hub face or foreign
material on mounting faces Tighten or install new parts. Clean mounting
surfaces.
Defective wheel bearings Install a new bearing set.
Brake disc imbalance
Water in tyres Remove water.
Loose engine or transmission mounts Install new mount nuts / install new mounts.
Incorrect front end alignment Align front end.
Loose or worn driveline or suspension
parts Repair or install new parts.
Excessive driveshaft runout or
imbalance Install a new driveshaft.
Worn or damaged flexible drive joint Install a new driveshaft.
Damaged wheel hub stud
threads Sliding wheel across the wheel studs
during installation. Loose wheel nuts
Install new wheel studs.
Broken wheel studs Loose or over tightened wheel nuts Install new wheel studs.
Corrosion and contamination
streaks from the wheel hub
wheel stud holes Loose wheel nuts Check complete assembly. Install new parts.
Damaged wheel nuts Loose wheel assembly Install new wheel nuts.
Over-tightened wheel nuts Install new wheel nuts.
Frozen wheel nuts Corrosion or galling If corrosion is light, wire brush away corrosion.
If corrosion is excessive install new wheel studs
and wheel nuts.
SymptomPossible Source(s):Action(s)
SymptomDescription
Age Deterioration Cracking and crazing of the tread and side wall rubber, sometimes accompanied by carcass
deformation. An indication that the tyres have been in service for a very long time.
Neglected Cut Damage through accidental cuts or penetrations will extend in use due to continued flexing and /
or ingress of moisture and road matter.
Impact Fracture Resultant damage from impact fractures is not always visible externally and, therefore, as a safety
precaution the tyre should be removed and examined.
Casing fracture caused by severe localized impact through driving over kerbs, hitting potholes
and / or objects in the road.
A double fracture caused by crushing the side wall of the tyre between an object and the rim
flange.
In both instances, such damage can lead to sudd en and dangerous tyre deflation some time after
the impact occurred.
Road Wheels and Tyres (04.04)
Suspension (04.00)4-4-10 Workshop Manual May 2007
Display Unit
The display unit provides additional features when correctly
connected to a previously installed ‘Smartire’ system. The
display unit connects directly to the front of the basic
‘Smartire’ receiver and is powered from the vehicle circuits.
The display will be fully illu minated during use but will go
into ‘Energy Saver’ mode when no activity is detected.
Display Panel
Connection and Normal Operation
1. Remove the front bezel of the Pressure Sensor Receiver. Install the extension lead to the display unit and to the
receiver module. Turn on the ignition.
All icons will illuminate briefly and then extinguish
leaving only the vehicle outline.
2. When tyre pressure data is received, (drive the vehicle
or spin the road wheels), all the road wheel icons will
appear. Press the Tyre icon to access the recorded data
for each of the four road wheels.
3. Press the Mode button to scroll through the pressure, temperature and pressure deviation readings for the
selected tyre. 4. If any tyre pressure sensor is defective, the display will
show three dashes to indicate the absence of data for
that tyre.
5. To return to normal mode, press the SET button.
System Programming
The system may be programmed by the user on three
different levels. Enter Progra mming Mode by pressing the
‘Set’ button:
• 2 seconds to enter level 1
• 5 seconds to enter level 2
• 10 seconds to enter level 3
The following parameters ma y be set in each level:
Level 1 Programming
Cold inflation pressure
1. Press ‘Set’ for 2 seconds to enter level 1 programming .
2. Press ‘Tyre’ to select the front or rear axle. Front or rear
tyres will be highlighted.
3. Press ‘Mode’ to show the current value. Press ‘Tyre’ to increase or ‘Mode’ to decrease the current value.
4. Press ‘Set’ to save the new values.
5. Repeat steps 2 - 4 to set the cold inflation pressure for other the axle.
Programmed wheel position No data
Data received
Alarm light Low pressure warning
Alert indicatorLearn mode MODE button
Set button
Tyre rotation program
Cold pressure program
Programming mode
Towing vehicle indicator
Numerical display
Units of pressure or temperature TYRE button
36-5-038
36-5-039
Level 1
• Cold Pressure
• Tyre Rotation
• Low Pressure Warning
• Pressure Deviation
• High Temperature Alert
•Units Selection
Level 2 •Slope
• Learn Transmitter ID
Level 3 • Low Pressure Alert
PSI
36-5-045