Wheels/Tires - Steering Wheel Vibration/Oscillation
44 Steering wheel shimmy, vibration and/or oscillation
44 10 02
2022563/2
May 18, 2010
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Supersedes Technical DIAGNOSIS AND REPAIR Group 44 number 10-01 dated January 27, 2010 for reasons listed below.
Affected Vehicles
Condition
Complaints of steering wheel vibration and/or steering wheel oscillation while driving at highway speeds.
This condition does not result in any handling concerns or loss of vehicle control.
Technical Background
The above stated conditions may be caused by the following:
^ Imbalanced wheel and tire assembly.
^ Tires with high road force values.
EXPLANATIONS AND DEFINITIONS
Radial force variation
The radial force is the force with which a tire is compressed.
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Tires have softer and stiffer areas along their circumference. In Figure 2, the softer and stiffer areas are illustrated by different size springs.
If this wheel rolls on level road with constant wheel load (Figure 2, arrow 1), the center of the wheel rises and falls by the amount (x) because of the
varying spring hardness. The change by the amount (x) can be felt in the vehicle as vibration or shaking of the steering wheel.
The change of the compression force of the tire is the radial force variation.
To measure the radial force variation, a constant force is applied to the tire on a vibration control unit (such as Hunter's VAS 6230 Road Force
Measurement(R) System vibration control unit [GSP9700] or similar), and the tire is operated. This simulates the pull out of the tire on the road
surface. The variation of the radial force is independent of the turning direction and is measured as the difference of maximum and minimal radial
force (peak-to-peak value, or Total Indicated Reading [T.I.R.]).
On Audi vehicles the peak-to-peak value (T.I.R.) must be 27 lbs. or less.
Harmonic vibrations
The wheel force variations during the turn of the wheel can be mathematically divided into individual harmonic vibrations.
For an objective assessment of the tire stiffness, the first harmonic (the basic vibration) is used.
The basic vibration or first harmonic is the share of the radial force variation that causes the strongest vibrations.
On Audi vehicles the first harmonic (road force) must be 18 lbs. or less.
Production Solution
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Warranty
Tire warranty facts when submitting tire claims through the Audi Tire Warranty Assistance Program (ATAP)
The Audi Tire Assistance Program is not an Audi of America, Inc. factory warranty. Audi of America, Inc. does not warranty tires originally
installed or sold as replacement for use on Audi vehicles. Individual tire manufacturers provide all the underlying tire warranties.
Dealer Tire
^ Tires are warranted through the specific tire manufacturer
^ Tire Coverage applicable per tire manufacturer guidelines
^ 0 to 6,000 miles 100% coverage at dealer net
^ 6,001 to 12,000 miles 50% coverage at current dealer net
What is eligible?
1. Tire tread depth must be no more than 2/32 of an inch (1.6). At 2/32 of an inch tread depth, the tire is considered worn to the limit.
2. A defect in material and workmanship is present.
3. Originally installed tires (original equipment tires) are on the vehicle for which they are designated.
4. Replacement tire(s) must be purchased through the Audi Tire Center.
5. The replacement tire(s) must have the same tire size, load rating, speed rating, and be the same tire model from the same tire manufacturer.
Ride disturbance
^ Ride disturbance cases include out-of-round, excessive vibration, and lateral/radial pull conditions
^ For most tire manufacturers, this condition is only covered if the tire has no more than 2/32-inch of wear from its maximum tread depth (1/32-inch
for Bridgestone and Toyo brand tires)
^ Ride disturbance claims are eligible only if they are not a result of:
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^ Poor tire maintenance
^ Temporary flat spotting (goes away after vehicle is driven for approximately 20 miles)
^ Out of balance conditions caused by outside influence
For all ride disturbance claims, it is required that proper diagnosis is followed and documentation is retained (e.g., balance data, road force
measurement data)
What is not eligible?
Tire conditions, which are not eligible for the ATAP, include, but are not limited to:
1. Tires that have exceeded the time or mileage limits of the ATAP
2. Tire damage due to outside influence or road hazard (e.g., curb or pot hole damage), use of non-approved cleaning agents, or as a result of being
used in a racing/competitive event
3. Tire damage/wear due to improper or lack of tire rotation, and/or incorrect vehicle alignment
4. Tires worn due to misuse or failure of another component
5. Tires worn down to or below 2/32 of an inch (to wear bars)
6. Over-inflated or under-inflated tires
7. Flat spotted tires due to brake lock-up
8. Replacement tires not purchased through the Audi Tire Store
9. Tires not approved for specific Audi models (e.g., Audi-approved A4 tire on an Audi A5)
10. Tires that have been modified (shaved, for example)
11. Tires injected with sealants, dry or liquid balancers
12. Tires with the U.S. Department of Transportation (DOT) identification number removed or rendered illegible
Other reimbursement questions or concerns
For any additional reimbursement questions or concerns outside of the above instructions, please contact your Audi claims specialist team.
Required Parts and Tools
Tools
^ Use VAS 6230 Vibration Control Tire Balancer or similar Road Force Measurements(R) System to check balance, Road Force values, and to
make necessary adjustments.
^ Use centering hub in conjuction with VAS 6243 model-specific clamping plate (5 finger clamping device) or similar device to ensure proper
mounting of wheel and to prevent damage to wheels.
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^ Vetronix MTS 4100 NVH Analyzer is helpful when diagnosing vibration concerns and can help[ narrow down the list of possible sources of the
vibration.
Additional Information
More information can be found in the following resources:
^ ELSAWeb: Wheel and Tire Guide >> Diagnosing and Testing
^ SSP: Noise, Vibration. and harshness 961403
The following repair procedure(s) will be necessary to complete this procedure:
^ Chassis >> Wheel and Tire guide >> Diagnosis and testing
All parts and service references provided in the TSB are subject to change and/or removal. Always check with your Parts department and service
manuals for the latest information.
Tire Data Sheet
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Vibrations and steering wheel oscillation
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7.4 service mode Setup and Features
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Programmed Road Force(TM) Limits
Service
Service
For Service Advisor
It is critical to address all of the points listed in order to ensure that the conditions observed during the test drive are valid concerns.
1. Ask customer appropriate questions based on attached questionnaires. Enter all information and attach copies to Repair Order.
2. Check tire pressures, which must be set according to what is recommended in the Owner's Manual. (Use Bartec TPMS tool (BRT-DBL4) to check
current tire pressures. Record on Repair Order and questionnaire.)
3. Check wheels and tires for any damage.
4. Make sure that Audi-approved wheels and tires are installed. (See Owner's Manual.)
5. Always address any concerns with the customer prior to further diagnosis.
6. Test drive vehicle with customer to verify vibration complaint.
7. Continue with Technician test drive.
Technician test drive
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1. Check tire pressures, which must be set according to what is recommended in the Owner's Manual. (Record on Repair Order and questionnaire.)
2. Check wheels and tires for any damage.
3. Check suspension and steering components for damage.
4. Make sure that Audi-approved wheels and tires are installed. (See Owner's Manual.)
5. Always address any concerns with the customer prior to further diagnosis.
6. Warm tires by driving the vehicle for at least 20 miles (32 km) over various speed ranges (including highway driving at speeds greater than 55
mph / 88 kph). Tires must be warm in order for the test drive to be effective since cold tires may produce a vibration due to temporary flat spotting.
(See Flat spots section below.)
7. If vibration no longer exists, advise customer of flat spotting.
Flat spots
After a stationary period of only a few hours, flat spots are created as the warm tire cools down. Depending on the type, size and make of the tire, flat
spots may appear more often. See information on flat spots in the Repair Manual under Suspension, Wheels, Steering >> Wheel and Tire Guide >>
44 Wheels, Tires, Wheel Alignment >> Diagnosis and Testing >> Wheel and Tire Vibration >> Tire Flat Spots from Standing.
Tip: Flat spots are normal and no replacement of tires is necessary.
1. Flat spots falsify the radial force variation and must be driven out before balancing the wheel. Complete a test drive of at least 20 miles (32km)
over various speed ranges (including highway driving at speeds greater than 55 mph / 88 kph).
2. Immediately after the test drive, raise vehicle to prevent temporary flat spotting and check road force and balance of each tire using VAS 6230(A)
Hunter vibration control unit (GSP9700) or similar. Remove and balance the wheels immediately following the test drive. On cooled-down tires, flat
spots may reappear.
3. If vibration exists, reduce the radial force variation.
Effects of increased radial forces on the vehicle
Measure and reduce the radial force variation
1. Optimize the radial forces on a VAS 6230(A) Hunter vibration control unit (GSP9700 Road Force Measurement(R)) or similar tool.
When tightening the wheel on the balancing machine, make sure the contact surfaces of flange and wheel are clean, the wheel is correctly centered,
and a suitable cone and clamping plate are used.
Note:
It is mandatory to use the five-finger clamping plate (VAS 6243 or similar) when mounting wheels to avoid damage of wheels and for proper
balancing.
2. Set the tire pressure of every wheel to 2.5 bar (36 PSI).
3. Ensure the VAS 6230(A) or Hunter GSP9700 is set to proper road force limits as shown in the attached document GSP 9700 Operation
Manual_P104_105.
4. Ensure that the machine is properly anchored to the floor to prevent improper readings.
5. Measure, balance and if necessary match the wheel according to the instructions of the machine. Use the value for the first harmonic vibration (18
lbs. maximum).
Tip: Do not use "Quick Match" mode; this mode does not measure road force. Also turn off "Smart Weight" balance feature, which can cause
inaccurate readings.
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6. Ensure that the wheel is centered and properly secured on the shaft of the balancer.
7. Follow all on-screen instructions to improve balance and reduce road force values (e.g. "Force Matching"). It is required to reduce road force to
the lowest possible value on all tires with a maximum value of 18 lbs.
8. Visually check the rim runout. If any runout is suspected, remove the tire and check radial and lateral runout values using VAS 6230 or Hunter
GSP9700 Tire Balancer.
Tip: Use adequate lubrication to ensure that tires are properly seated when they are installed on the wheel or are moved on a wheel to change
mounting position. Be aware that excessive lubricant can cause a tire to slip on the wheel, which will have an impact on the balance and road force
values. Please ensure that the road force values are printed out with the before and after values for each wheel and attach this documentation to the
Repair Order.
9. If the original tires are installed on the vehicle and it is not possible to reduce the road force below 18 lbs., replace the affected tire with another
tire of the same brand, size and load rating as the original.
Tip: A replacement is permitted only if the original tires are installed on the vehicle.
Tip: In case of high road force values in the replacement tire, it may be necessary to repeat steps 1 through 8.
10. Install the wheels according to instructions of the VAS 6230 according to the lowest vibration. The wheels/tire assembly with the lowest road
force values should be installed closest to the driver. Keep in mind that directional tires may not allow every tire to be installed in its ideal position
on the vehicle. See Repair Manual >> Running gear >> 44 wheels, tires, wheel alignment >> Installation of wheels/ tires/ tire pressure warning >>
Instructions on wheel change/installation.
^ Lowest road force value left front
^ Second lowest road force value right front
^ Third lowest road force value left rear
^ Highest road force value right rear
11. Test drive vehicle and verify repair.
12. If the vibrations or steering wheel vibrations persist, open an Audi Technical Assistance Center ticket. The ticket must include the following
information:
^ The completed tire questionnaires.
Tip: If the questionnaires are not attached to the ticket prior to contacting an Audi TAC consultant, you will have to call back.
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^ Exact speed range at which the vibration or steering wheel oscillation occurs.
^ List of all repairs performed prior to contacting the TAC.
^ List of all road force values and their position on the vehicle.
^ List of all lateral and radial rim runout values from VAS 6230 or Hunter GSP9700 Tire Balancer.
^ Tire brand, model and size (including speed and load ratings).
