2021 Mercedes-Benz AMG GT Steering Wheel Grinding Noise TSB

Mercedes-Benz has issued Technical Service Bulletin (TSB) LI46.10-P-077313 to address concerns regarding Mercedes-Benz AMG GT steering noise. This bulletin, dated January 22, 2024, applies to vehicles produced as of model year 2019 and specifically details a repair for grinding noises originating from the steering wheel area.

Symptoms

Owners of affected vehicles may notice various types of Mercedes-Benz AMG GT steering noise during steering maneuvers. The reported symptoms include:

• Grinding noises from the steering wheel.
• Creaking or cracking noises.
• Dragging or squealing sounds from the steering system.
• The steering wheel vibrating.
• The steering wheel exhibiting pulses.

These noises are typically heard when turning the steering wheel and can be indicative of the underlying issue described in the TSB.

Cause

The primary cause of the Mercedes-Benz AMG GT steering noise is identified as a plastic cover on the back of the steering wheel being incorrectly positioned. This improper positioning leads to the plastic cover rubbing against the steering column switch module during normal operation, generating the audible grinding and other noises.

Diagnosis

To accurately diagnose the source of the noise, technicians are advised to perform a specific check for grinding areas on the steering wheel. This involves:

1. Inspecting the covers on the rear of the steering wheel for any protrusion and remounting them if necessary.
2. Masking off any openings on the back of the steering wheel using adhesive tape.
3. Marking the back of the steering wheel with colored chalk, as shown in Picture 1 of the bulletin.
4. Mounting the steering wheel onto the steering column switch module and turning it from left lock to right lock ten times.
5. Observing the chalk marks, which will have disappeared in the areas where rubbing has occurred, as depicted in Picture 2.

Audio files, such as "Lenkrad-Schleifgeräusch_SteeringWheel-GrindingNoises.mp4" for steering wheel noise and "MRSM-Schleifgeräusch_SCCM-GrindingNoises.MOV" for steering column switch module noise, are provided to help technicians identify the specific type of noise. If the noise is determined to be from the steering column switch module, reference TSB LI46.10-P-077314 for further guidance.

Repair Procedure Summary

The repair procedure outlined in TSB LI46.10-P-077313 focuses on carefully removing the excess material causing the rubbing. After identifying the grinding areas using the chalk test, technicians will:

1. Use a Dremel tool to carefully remove approximately 0.1 mm to 0.3 mm of the abrasive excess material from the back of the steering wheel (refer to Picture 3).
2. Ensure that no cables or visible areas of the steering wheel are damaged during this process.
3. Take precautions to prevent any ground-off material from entering the steering wheel.
4. After material removal, clean the entire back of the steering wheel with a 1% soap solution.

Required Tools or Parts

Technicians will need the following items to perform the diagnosis and repair:

• Adhesive tape
• Colored chalk
• Dremel tool
• 1% soap solution

Important Warnings

Mercedes-Benz includes several critical warnings within the TSB to ensure proper repair and prevent further damage or safety issues:

• "Ensure that no cables and visible areas of the steering wheel are damaged."
• "Make sure that none of the ground-off material gets into the steering wheel."
• "Do not blow off the steering wheel with compressed air."

What Owners Should Do

If you own a 2021 Mercedes-Benz AMG GT and are experiencing grinding, creaking, or other unusual Mercedes-Benz AMG GT steering noise, it is recommended to contact your authorized Mercedes-Benz dealership. They can perform the diagnostic procedures outlined in TSB LI46.10-P-077313 to identify the source of the noise and carry out the necessary repair. The damage code associated with this issue is 4624836.

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Source: NHTSA ID: 10249482