Steering - Highway Speed Steering Wheel Oscillation
40 Steering wheel vibrations
40 12 25
2024687/3
August 7, 2012
Supersedes Technical DIAGNOSIS AND REPAIR Group 40 number 11 - 19 dated December 9, 2011 for reasons listed below.
Affected Vehicles
Audi A4 Quattro Sedan (8K2) L4-2.0L Turbo (CAEB) Page 91
Condition
Customer complaint:
Steering wheel oscillation at highway speeds.
Workshop findings:
^ Steering wheel oscillation, typically at a speed between 70 and 85 mph.
^ TSB 2022179 has been completed and the 1st harmonic of radial force of every tire and wheel assembly is below 18 lbs. at a tire pressure of
2.5bar.
^ Audi original equipment tires are installed on the vehicle.
^ The complaint does not involve vibration in the seat surface or other vehicle components.
Technical Background
Steering wheel vibrations and oscillations are caused by uneven roads, wheel imbalance, impermissibly high radial forces of the tires or other
rotating components on the front of the vehicle.
These ride disturbances are transmitted from the front axle and the steering system to the steering wheel.
Steering wheel oscillations are visible side-to-side movements of the steering wheel spokes and no other vibrations such as in the driver seat or the
vehicle floor are involved. If there are vibrations in the complete vehicle, i.e. in the driver seat and vehicle floor, installing the guide links with
updated bushings will not resolve the concern.
Production Solution
Updated front guide links (aka wishbone links) are equipped with larger fluid-filled bushings that help dampen steering wheel oscillation.
Service
1. Clearly verify steering wheel oscillation. Ensure TSB 2022179 has been completed and Audi original equipment tires are installed on the
vehicle. Each wheel and tire assembly must have less than 18 lbs. of road force variation.
Audi A4 Quattro Sedan (8K2) L4-2.0L Turbo (CAEB) Page 92
2. Inspect the front guide links to determine which guide links are installed. The guide link is pictured in Figure 3, point 7.
The updated guide link has a larger fluid-filled bushing that is 75 mm in diameter.
3. If the vehicle is equipped with the original guide links that have the smaller 65 mm bushing, search ETKA by VIN and check the size of the
shouldered hex. nut (6). Example of the ETKA screen shot is pictured in Figure 5, point 6. Determine which guide links are required based on
Audi A4 Quattro Sedan (8K2) L4-2.0L Turbo (CAEB) Page 93
the following:
^ For size M12 shouldered hex. nut use 8K0 498 998 guide link conversion kit - M12
^ For size M14 shouldered hex. nut use 8K0 498 998 A guide link conversion kit - M14
Tip: Guide links are available with two different size ball joints which are not interchangeable. Use the shouldered hex. nut (6) size to
determine the correct guide link for the VIN.
4. Install updated guide link conversion kit per the Required Parts and Tools chart below. If the kit part number is not available, guide links can
be ordered by their individual part numbers.
Tip: The bolts and nuts used to install the guide links are one-time-use and must be replaced after each removal.
Warranty
Required Parts and Tools
Additional Information
More information on this system can be found in the following resources:
^ ElsaWeb: Chassis >> Suspension, Wheels, Steering >> Front Suspension >> Specifications >> Fastener Tightening Specification.
The following Technical DIAGNOSIS AND REPAIR(s) will be necessary to complete this procedure:
Audi A4 Quattro Sedan (8K2) L4-2.0L Turbo (CAEB) Page 94
^ TSB 2022179, 44 Steering wheel shimmy, vibration and/or oscillation at 55 mph or greater
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service
manuals for the latest information.
