2021 Mercedes-Benz AMG GT Fixed Rear Spoiler Wind Noise TSB

Symptoms

Owners of affected 2021 Mercedes-Benz AMG GT models may notice a "Whistling noise/wind noise" emanating from the area of the fixed rear spoiler. This noise is typically perceived at speeds starting from approximately 50 mph (80 kph). The symptom is categorized by Mercedes-Benz as "Body > Body/Cab > Spoiler > Operation, noises."

Diagnosis / Trigger Conditions

The primary trigger for the "AMG GT spoiler wind noise" is vehicle speed. The whistling or wind noise becomes noticeable when the vehicle reaches speeds of 50 mph (80 kph) or higher. The root cause is attributed to the interaction of wind with the fixed rear spoiler, creating an aerodynamic disturbance that results in the audible noise.

Repair Procedure Summary

Mercedes-Benz TSB LI77.25-P-074448 outlines a specific repair procedure to address the AMG GT spoiler wind noise. The process involves modifying the fixed rear spoiler to improve its aerodynamic properties and eliminate the unwanted noise.

1. Disassembly: Technicians will begin by disassembling the upper spoiler, identified as Position 825, part number A1907932600. This step allows access to the bonding area underneath (as shown in Picture 1 of the TSB).
2. Surface Preparation: The bonding area is then thoroughly cleaned using an alcohol-based cleaner. This ensures the removal of all dust and grease, preparing the surface for optimal adhesion of the new seal (as depicted in Picture 2).
3. Seal Installation: Two strips of elastomer seal, part number A1977520098, approximately 335 mm long, are applied. These strips are installed on both the left and right sides, starting at point Z in the Y-direction. A crucial detail is to leave a gap of approximately 10-20 mm around the Y0 point, which serves as a water drain (illustrated in Picture 3).
4. Adhesion: A roller is used to uniformly and carefully press the elastomer seal with approximately 40-50 N of force. This ensures proper adhesion and eliminates air pockets.
5. Reassembly: Finally, the upper spoiler is reassembled. The screws (left and right) are tightened using Loctite 222 and a specific torque of 10 +/-1 Nm (as shown in Picture 4).

Required Tools or Parts

To perform this repair, the following specific parts and materials are required:

• Elastomer strip / seal: Part number A1977520098 (Quantity: 1). This is the key component to resolve the wind noise.
• Alcohol-based cleaner: Used for preparing the bonding surface.
• Roller: Essential for uniformly pressing the elastomer seal to ensure proper adhesion.
• Loctite 222: A threadlocker applied to the screws during reassembly to prevent loosening.

Important Warnings

This rework is ONLY VALID for specific vehicles within the Mercedes-Benz model series 190. It applies exclusively to vehicles equipped with option codes U11 and M032 (designating the Black Series) from their production startup up to and including the production date of November 11, 2021. Owners of vehicles outside this specific production range or without these option codes should consult their dealer for diagnosis if they experience similar symptoms.

Owner Action

If your 2021 Mercedes-Benz AMG GT (Black Series, produced before November 11, 2021) is experiencing the "AMG GT spoiler wind noise" at speeds above 50 mph, you should schedule an appointment with an authorized Mercedes-Benz service center. Inform them about the whistling noise and mention Mercedes-Benz TSB LI77.25-P-074448. The dealership will diagnose the issue and perform the necessary repair as outlined in the technical service bulletin.

Source: NHTSA ID 10208743