Mercedes-Benz lunking Noises: Acceleration and Throttle Lift Off

Mercedes-Benz Tech Tip: Clunking Noises Heard During Acceleration And Throttle Lift Off

Owners of Mercedes-Benz cars with front-wheel drive and 4x4 vehicles, may complain of a single throttle lift-off clunking noise from the side shaft when first taking off (audible at the outboard end). Also, the clunk is heard once when changing from forward to reverse.

Photo 1

Models: All Mercedes-Benz cars with front-wheel drive and 4×4 vehicles.

Complaint: Single throttle lift-off clunking noise from the side shaft when first taking off (audible at the outboard end). Also, the clunk is heard once when changing from forward to reverse.

Cause: If the complaint is eliminated by experimentally loosening the outboard collar nut by one turn, the complaint is likely due to micro-movement in the connection between the wheel bearing inner race and the joint housing of the side shaft.

Note:
The collar nut must always be replaced after being loosened and must be tightened to the specified torque.

Photo 2

Remedy: Coat the contact surface of the shaft with wheel bearing using Molykote paint. To do this, proceed as follows:
1. Remove the outboard side shafts.
2. Clean the contact surface A (see Photo 1), making sure it is free of debris and oil.
3. Coat the contact surface A (see Photo 2) with Molykote and allow it to dry for one hour.
4. Reinstall the side shafts.

You May Also Like

Audi TFSI/FSI: Oil Consumption And Carbon Buildup

Technical Service Bulletins can be valuable in helping solve vehicle problems. But sometimes, it takes multiple TSBs to find a pattern failure or the “root cause” of a problem. In the case of the Audi/VW 2.0L Fuel Stratified Injection (FSI) engine introduced in 2006, three problems related to engine carbon and fuel issues are connected

Technical Service Bulletins can be valuable in helping solve vehicle problems. But sometimes, it takes multiple TSBs to find a pattern failure or the “root cause” of a problem. In the case of the Audi/VW 2.0L Fuel Stratified Injection (FSI) engine introduced in 2006, three problems related to engine carbon and fuel issues are connected through multiple TSBs.

BMW Diagnostics: Low Airflow After Cabin Filter Replacement

Models:  F97 X3 M  F98 X4 M G01 X3 G02 X4 G20 3-Series SITUATION After replacing the microfilter during a previous service, the customer notices that the ventilation system airflow rate is noticeably less. This leads to perceived lower cooling power. The customer may also notice that external odors enter the vehicle. Related Articles –

Volvo Modular Engine Service

The Volvo Modular Series engine outlasted Ford and was retired by Geely. The Volvo modular design that can have four, five or six cylinders made its debut in 1990 in the 960 sedan as a six-cylinder and never stopped improving. Related Articles – Audi Active Suspension Service – How To Service BMW Tire Monitor Systems

BMW Dual Clutch Transmissions

BMW uses a wet clutch with separate inboard and outboard sections for the two sub-transmission.

BMW Cooling System Problems

Let’s take a closer look at this unique water pump, how to replace it efficiently and what other components should be replaced along with it.

Other Posts

Now Available – March’s Digital Edition of ShopOwner

The March issue includes technical and management content and is free to download.

Now Available – February’s Digital Edition of ShopOwner

February’s issue includes technical and management content and is free to download.

Tech Tip: Checking Transmission Fluid Levels When Cold or Hot

Checking the fluid level before the transmission has reached the specified temperature might cause a false reading

Why Do Turbos Fail?

In the 1980s, it was not uncommon for a turbocharger on some European vehicles to last only 30,000 to 40,000 miles. The failures were almost always in the center section and caused by the lack of oil to cool and lubricate the bearings and shaft.  Related Articles – Air Ride Diagnostics: Reservoirs and Compressors –