2021 Audi A4, A5, Q7 Front End Noise TSB

Audi has released Technical Service Bulletin (TSB) 40 20 12 2047920/5 to address various noises originating from the front end and dash panel of certain vehicles. This bulletin, dated July 15, 2020, supersedes TSB 20-07 from May 18, 2020, and provides diagnostic and repair information for conditions where noise is heard while the vehicle is moving. Owners of a 2021 Audi A4, A5, or Q7 experiencing these symptoms should be aware of this service action.

Symptoms of Front End Noise

Owners may notice a distinct Audi A5 front end noise characterized by a "buzzing, booming, humming, whistling or a similar noise from the front end." This noise can also be heard from the steering area or behind the dash panel. It's important to note that these sounds may sometimes be mistaken for tire rolling noises due to their similar characteristics.

Workshop findings confirm that these noises are reproducible during a test drive, helping technicians accurately diagnose the issue. The underlying cause for this Audi A5 front end noise is mechanical damage to the wheel bearing of the front axle.

Diagnosis and Trigger Conditions

Diagnosing the exact source of a front-end noise can be challenging, as noises from the wheel bearing can transmit through the steering system into the vehicle's interior. To help distinguish wheel bearing noise from other sounds, such as tire rolling noises, technicians follow a series of diagnostic questions:

• Does the noise frequency increase as the vehicle speed increases, or does the sound get higher?
• Does the noise get louder when steering?
• Is the noise still present when slowing down?
• Is the noise amplified on the steering wheel or airbag well?
• Can vibrations be felt on the unpressed coil spring when the wheel is turning?
• When swapping around the wheel bearings, does the noise move with a particular bearing?

It is crucial to precisely locate the source of the noise using acoustic testers. Audi advises that a noise perceived on the left side of the vehicle could potentially be caused by the right wheel bearing. An important warning from the TSB states: "Front wheel bearings should not be replaced in pairs." If the noise cannot be traced to a wheel bearing, technicians are instructed to continue their analysis on other vehicle components.

Repair Procedure Summary

The repair for the Audi A5 front end noise involves replacing the damaged front wheel bearing or the entire front hub with the bearing, depending on the specific model and whether one or both bearings are affected. The TSB outlines various labor operations for different models:

• For A4 and A5 (one front wheel bearing): Remove and install the front hub with bearing (Labor Operation 4067 1900) or replace the front wheel bearing (Labor Operation 4057 5550).
• For A4 and A5 (both front wheel bearings): Remove and install two front hubs with bearings (Labor Operation 4067 2000) or replace two front wheel bearings (Labor Operation 4057 5650).
• For A6 and A7 (one front wheel bearing): Remove and install the front hub with bearing (Labor Operation 4067 1950) or replace the front wheel bearing (Labor Operation 4057 5550).
• For A6 and A7 (both front wheel bearings): Remove and install two front hubs with bearings (Labor Operation 4067 2050) or replace two front wheel bearings (Labor Operation 4057 5650).
• For Q7 (one front wheel bearing): Remove and install the front hub with bearing (Labor Operation 4067 1900) or replace the front wheel bearing (Labor Operation 4057 5500).
• For Q7 (both front wheel bearings): Remove and install both front wheel bearings (Labor Operation 4067 2000) or replace two front wheel bearings (Labor Operation 4057 5600).

Diagnostic time includes a road test prior to and after the service procedure, each allotted 10 labor units (TU).

Required Parts and Tools

Technicians will need specific parts and tools for this repair. These include:

• Wheel bearings: Up to two, to be sourced via ETKA.
• Fasteners, Bolts, Nuts, and Screws: As needed per the repair manual, also sourced via ETKA.

Always consult ETKA and/or ELSA for the latest information and parts bulletins to ensure the correct components are used.

Warranty Information

This repair is generally covered under warranty for qualifying vehicles. The claim types are:

• Type 110: For vehicles up to 48 months or 50,000 miles.
• Type G10: For Audi Certified Pre-Owned (CPO) vehicles, requiring owner verification.

The Service Number for this issue is 4057, and the Damage Code is 0020. All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual and are subject to review or audit by Audi Warranty. It's important to note: "If vehicle is outside any warranty, this Technical Service Bulletin is informational only."

Important Warnings

Owners should be aware of a critical instruction for technicians: "Front wheel bearings should not be replaced in pairs." This guidance helps ensure proper diagnosis and prevents unnecessary repairs.

NHTSA ID: 10177409