2021-2024 Audi Cracking Noise from Front End TSB 2061464/7

Symptoms

Owners of certain 2021-2024 Audi models may experience an Audi cracking noise front end or rear end. This noise is typically heard when changing direction or when accelerating from a standstill. Specifically, the TSB describes the symptom as a "cracking noise can be heard from the vehicle's front end, or the rear end on quattro vehicles." It can also be heard "from the left/right side of the vehicle's front or rear end after changing direction" when driving away from a standstill.

Diagnosis and Trigger Conditions

Workshop findings indicate that the Audi cracking noise front end or rear end occurs when the vehicle changes direction or moves away from a standstill. For quattro vehicles, the noise may also be attributed to the prop shaft in isolated cases. The underlying technical issue is identified as relative movement between the stub axle of the drive shaft and the wheel bearing.

Technical Background

Audi has determined that the cracking noise originates from the relative movement of the stub axle of the drive shaft within the wheel bearing. To address this, a production solution involving the gradual introduction of optimized stub axle splines in the outer joint has been implemented. For vehicles already on the road, a service procedure is available.

Repair Procedure Summary

To resolve the cracking noise, technicians will follow specific instructions outlined in the ELSA Repair Manual, focusing on the chassis, suspension, wheels, and steering components related to the front axle and drive axle. The main step involves bonding the stub axle of the drive shaft into the wheel bearing using a specialized locking fluid, part number D 154100A1. Approximately 5 ml of this fluid is required for each drive shaft, applied in two continuous beads: one where the splines begin and another at the center of the splines. After applying the fluid, the drive axle is reinstalled according to ELSA instructions.

Required Parts and Tools

The primary part required for this repair is locking fluid, specifically part number D 154100A1. Technicians will also need various fasteners, bolts, nuts, and screws as specified in the Repair Manual or ETKA/ELSA for proper reassembly.

Important Warnings

After the drive axle(s) have been assembled and the locking fluid applied, it is crucial that the vehicle must not be operated for 8 hours. This allows the locking fluid to properly cure and ensure the repair is effective and durable.

Warranty Information

This Technical Service Bulletin 40 24 79 2061464/7 outlines specific warranty claim details. The service number for this repair is 4041/4221, with a damage code of 0010. Labor operations include:

• Bond in 1 front outer driveshaft: Labor operation 4041 4999 (90 Time Units), including removing and installing one wheel, noise insulation, and detaching/reattaching a suspension link.
• Bond in 2 front outer driveshafts: Labor operation 4041 5099 (120 Time Units), including removing and installing two wheels, noise insulation, and detaching/reattaching two suspension links.
• Rear Axle operations: Specific labor codes for removing/installing wheel hubs with bearings (4267 19XX, 4267 20XX) and bonding rear outer drive shafts (4221 4999 for one, 4221 5099 for two) are also provided.

Diagnostic time includes a road test prior to the service procedure (0121 0002, 10 Time Units) and a road test after the service procedure (0121 0004, 10 Time Units). Warranty claims must adhere to the Audi Warranty Policies and Procedures Manual.

This TSB supersedes Technical Service Bulletin Group 40 number 24-73 dated February 9, 2024.

What Owners Should Know

If your 2021-2024 Audi is exhibiting an Audi cracking noise front end or rear end, especially when changing direction or starting from a stop, it is recommended to contact your authorized Audi service center. Reference Technical Service Bulletin 40 24 79 2061464/7 when discussing the issue with your technician. The repair involves a specific procedure and a curing period, so plan for your vehicle to be out of service for at least 8 hours after the repair is completed.

Source: NHTSA ID: 11009333