2012 Mercedes-Benz C-Class SUSPENSION,STRUCTURE
Owner-reported problems and safety issues filed with NHTSA. Review common failures, severity levels, and complaint trends over time.
Complaint Timeline
Chronological view of owner reports
Mercedes of Danbury replaced the rear sub frame CODE 3441 47, since my mechanic (Newtown Auto Repair) told me that the Front subframe is in real bad shape, rotten/rusted, that it is dangerous to drive the car in this condition since the wheel and steering components are part and attached to it, the car would be out of control and all over the road any of these components fail and pull / brake away from the rusted out Sub Frame. When I brought the car in was under the impression that Mercedes Benz would replace front and back Sub Frames. But now they informed me of only recall on rear subframe, rear subframe will let go wheels will collapse, front controls the car and failing could kill people and total the car. frames.
The contact owns a 2012 Mercedes-Benz C300. The contact stated while driving at an undisclosed speed, he heard an abnormal sound coming from the rear of the vehicle, prompting him to pull to the shoulder of the roadway. After a visual inspection, the contact observed that both trailing arms had become detached. No warning lights were illuminated. The vehicle was taken to an independent mechanic, who determined that extensive frame corrosion had caused both trailing arms to detach. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 143,000.
The subframe assembly on my car is defective, as I learned today from my mechanic. This issue is known for my model of car and widely reported online. The mechanic says they have seen this issue before. I heard a strange noise while driving so I took the car to the shop after 60 days of enduring the sound. The shop immediately deemed the car unfit for driving and unsafe. In their words, if I had hit one bad pothole, the wheels could have come off the back of my car, and my gas tank could have been punctured, leading to a potentially catastrophic accident. I am lucky to have gotten this defective part identified before being injured, and others need to be protected from this outcome before a serious injury occurs. As of now this has only been inspected by the shop doing the fix. People online have indicated that Mercedes will not fix the problem free of charge - and in fact they charge a premium to other places to replace this faulty subframe. There were zero warning indicators of this dangerous issue - the car drove completely normally aside from an infrequent knocking sound that would occur every 5-10 minutes under normal city driving conditions.
Sub Frame broke from rust. Mercedes Benz has acknowledged the issue in Europe and repaired/replaced the part at no charge. Numerous problems and complaints can be found on line indicating that we, the car owner must and can complain to Mercedes for partial or complete support on the repair. But they do not acknowledge the problem in the US.
Rear Subframe Cracking in Mercedes Benz 2012, C- Class, Sports. It can be life threatening for driver and passengers. Cost is $5700 for repairs. This replacement is free in Europe and Canada.
The contact owns a 2012 Mercedes-Benz C300. The contact stated that upon taking his vehicle to a dealer for maintenance repairs; he was provided an estimate for the repair of corrosion to the rear subframe of the vehicle. Upon investigation, the contact discovered that the failure could lead to a potential braking system failure. The manufacturer was notified of the failure and informed him that there were no recalls on the vehicle. The vehicle was not repaired. The failure mileage was approximately 97,000.
The contact owns a 2012 Mercedes-Benz C300. The contact stated while driving approximately 2 MPH over a speed bump, there was a loud cranking sound coming from the vehicle. There were no warning lights illuminated. The vehicle was taken to the local dealer and diagnosed with failure to the rear subframe due to severe rust. The vehicle was repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 121,218.
The contact owns a 2012 Mercedes-Benz C300. The contact stated that while having an oil change performed on the vehicle by an independent mechanic, he was informed that the cross member was severely corroded. The contact was informed by the mechanic that the vehicle was unsafe to drive. Neither the dealer nor the manufacturer had been notified of the failure. The vehicle was not repaired. The failure mileage was approximately 125,000.
The contact owns a 2012 Mercedes-Benz C300. The contact stated while driving 70 MPH, there was an abnormally loud sound from the rear of the vehicle. The contact lost control of the vehicle. There was no warning light illuminated. The contact was able to continue normal driving once he regained control of the vehicle. The contact scheduled an appointment with an independent mechanic for the vehicle to be inspected. The contact was informed that the rear subframe had detached from the passenger’s side of the vehicle due to severe corrosion. The dealer was notified of the failure and informed him that there were no recalls related to the failure on his vehicle. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 138,000.
The contact owns a 2012 Mercedes-Benz C300. The contact stated while driving approximately 65-70 MPH, he heard abnormal clicking sounds coming from the rear of the vehicle. Additionally, the contact stated that while driving and depressing the brake pedal to come to a complete stop, the vehicle swerved while stopping. The vehicle was taken to an independent mechanic where it was diagnosed that the rear driver's side subframe was severely corroded and fractured and needed to be replaced. The dealer was notified of the failure and informed the contact that the vehicle would be repaired at his own expense. The vehicle was not repaired. The manufacturer was notified of the failure but did not provide any assistance. The failure mileage was approximately 75,000.
I was driving my 2012 Mercedes C250 through an intersection on 08/09/2021 when I first heard clunking noises in the rear of my vehicle. Every time I placed my foot on the brakes after that it continued to clunk until I took it to the Mercedes dealership for repair on 08/17/2021. The car had about 57,000 miles on it and was only nine years old, but the dealership said that the entire rear subframe of the vehicle had rusted and was close to completely separating from other parts of the vehicle. This was the first time I heard of any rusting in my vehicle, despite having the 2 rear tires replaced and alignment by the same place on 10/02/2020 (less than one year before). The service rep acknowledged that the car was well-maintained and that this was not due to any accident. This rusting was due to a manufacturing defect and has caused accidents in other Mercedes vehicles (https://www.carproblemzoo.com/mercedesbenz/c300/suspension-problems.php). It has resulted in recalls of rusted parts in both Europe (https://europe.autonews.com/article/19981026/ANE/810260839/mercedes-offers-guarantee-against-rust-for-30-years) and Canada (https://www.wheels.ca/news/mercedes-benz-recalling-vehicles-for-rust-problems/). Had I been travelling at a higher rate of speed when this piece failed, I could have been at risk of serious injury. This event occurred without any warning lamps or messages. The service for replacement and realignment was quoted at $4,358.71. Only after much argument did I receive a final bill of $3448.71. This was an unbelievable cost for replacing a part with a manufacturer defect. Mercedes headquarters tried to claim that the issue was due to exposure to snow and salt on the roads. This region rarely gets any snow. This lack of care for customer safety along with the fact that the dealership did not retain the part they removed from my vehicle after I had requested them to do so, left me realizing that Mercedes doesn't care about safety standards for their products.
1. The (RH) rear suspension forward link attach point on the rear Suspension Cross-Member (Mercedes-Benz P/N: 204-350-01-41), separated from the sub frame due to internal corrosion of the Suspension Cross-Member. Part available for inspection. 2. When part failed, the RH rear wheel alignment was no-longer fixed; some loss of vehicle steering control was experienced, especially during braking and also turning. 3. Numerous reports of similar episodes of this failure are reported in owners' and maintainers' forums. The dealer service department was familiar with this Suspension Cross-Member part failure. 5. This vehicle passed a Maryland State safety inspection performed by the seller of the vehicle 6 months and 5000 mi prior to the part failure. 6. Part failed with no warning, during normal driving on secondary roads.
REAR SUBFRAME (AS RECALLED IN PREVIOUS YEARS) WAS COMPLETED CORRODED - FAILED VIRGINIA INSPECTION - IN SUCH POOR SHAPE THAT ENTIRE SUBFRAME HAD TO BE REPLACED - CORROSION RIDDLED THE PIECE SO THAT HUGE HOLES RESULTED IN NO POSSIBILITY OF WELDING TO FIX/SUPPLEMENT WEAKNESS - AUTO REPAIR PLACE HAD NOT SEEN SUCH A WEAK FRAME IN SUCH A RELATIVELY NEW CAR. LUCKILY - NO ACCIDENT OCCURED BUT COULD EASILY HAVE OCCURRED DUE TO CORROSION. NO OTHER PART OF VEHICLE WAS CORRODED - SO PART WAS MANUFACTURED INCORRECTLY (NO CORROSION CONTROL?/SHIPMENT FROM GERMANY ISSUE?) - MERCEDES BENZ HAS RECALL FOR THIS PART IN PREVIOUS MODEL YEARS - PICTURES OF SUBFRAME AVAILABLE UPON DEMAND
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Quick Summary
The 2012 Mercedes-Benz C-Class has 13 SUSPENSION,STRUCTURE complaints on file. Review the timeline above for detailed owner experiences.