So here I am - another "happy" driver with a rotten subframe. Started noticing instability on the highway speeds a few months ago. Cracking noises lately. Since I use this car my very honest mechanic immediately told me that my rear subframe is completely done and I should not be driving the car until it is replaced. He quoted me $4500 (OEM parts + labor), but suggested that I take my car to MB and insist on covering the repair costs as this issue did not seem typical to him at all. I started googling and ended up here. Seems like this is a common issue and sounds like MB will replace the subframe for free in some other countries (cananda and Germany, .The dealer said the repair will cost Over $5000 This is a safety issue, A real big one. And the fact it's covered in other countries is so not fair. I own another mercedes and now I feel the cars are not as safe as they used to be. Please let me know what I need to do next

- Nanuet , NY, USA

The rear sub frame has rusted out and broken causing the car to veer suddenly to the left during braking. A quick search of the internet reveals that this is a common problem with this car. The dealership has quoted me $4,000 for the repairs.

- Saint Louis, MO, USA

I was traveling at roughly 55mph when I had to make a sudden deceleration due to another vehicle pulling out in front of me. When I applied the brakes, the car unexpectedly pulled violently to the left nearly causing a head-on collision with an on coming vehicle. After Googling the symptoms/scenario, I found that this can be caused by a rusted and failed rear suspension subframe. The control arms for the rear wheels become detached from the subframe as a result. Based on my research, this seems to be an extremely common occurrence. So much so that Mercedes Canada and Mercedes Germany are replacing the defective subframes free of charge as they-??ve concluded the cause to be -??inadequate corrosion protection-?? applied to the inside of the subframe. It seems as though they-??re rotting from the inside out. After learning everything about the issue, I pulled my car on to ramps in my garage and was able to confirm that my subframe had indeed failed. This is a serious safety issue which is being addressed elsewhere. During my research I was unable to find a recall or TSB related to this issue, only hundreds of people stating that Mercedes forcing customers to cover the cost to repair this extremely dangerous manufacturing defect.

- Dublin, OH, USA

Part number: 207-350-97-02 This is the sub frame part number, during routine maintenance i found a cracked rear sub frame mount. Upon googling, there are hundreds of owners with that same problem. Cars with milage ranging from 40,000-150,0000 with the same issue. Under hard braking the car is unstable. When I called the MB dealer to inquire about the problem they did confirm that the problem is known but is not a safety recall and the repair bill is near $5,000. So Mercedes, confirmed it-??s a known issue with a faulty part, confirmed it was a safety issue with the 2008-2012 Mercedes c300 and is not covering it.

- Bolton, CT, USA

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.

- Bloomington, IL, USA

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.

- Beavercreek, OH, USA

The rear K frame on Mercedes Benz C300 totaly rusted through and broke apart causing the entire rear of vehicle to rest upon the fuel tank. The failure also caused stress on rear brake lines. The vehicle is 10 years old with 90,000 miles purchased brand new and garaged. Mercedes has performed a recall on Canada vehicles but no USA vehicles. This is total negligence. This is going to cause a fatality. Either a vehicle will catch fire or brake lines will fail and cause an accident. The vehicle is known by the dealers to have this damage/failure. I googled and found numerous cases. Mercedes was not willing to stand by the vehicle and repair. This should be a recall like it is in Canada. I was quoted $5000 to repair by Mercedes.

- Lincoln, RI, USA

I drove over an object on the highway and noticed my car veering left and wobbly when turning. A week after, it is squealing like a load of piglets in my trunk whenever I go over a bump, then my battery light came on and I took it to the shop and contacted my insurance, who denied my claim saying it was 'wear and tear'.

- Alexandria, VA, USA

From the mechanics notes: Four-wheel alignment could not be completed. Attempts to align the rear axle were unsuccessful due to flexing/movement in the rear suspension. A brief road test revealed occasional suspension -??clunking-?? coming from the rear of the vehicle. Close examination of every suspension component mount revealed heavy cracking on the passenger side lower drag link subframe mount (see emailed image). The driver-??s side low drag link mount location is also starting to show signs of overstress and rust/flaking. This is a known design defect that has been the subject of a manufacturer-??s recall in Canada. Given the substantial safety impact of this design defect/failure, it is expected that a US recall will be forthcoming. Proper repair of this failure involves removing the entire rear axle/subframe assembly and either rebuilding/re enforcing the subframe or replacing it with a new unit and transferring all the suspension components to the new subframe. A current check of subframe availability is showing NLA (no longer available) status from Mercedes wholesale dealers -?" likely due to recent high demand and inability to satisfy that demand. This supply issue may also be playing a role in Mercedes-?? failure to address this high level safety issue with a US based recall campaign. The manufacturer may be ramping up production of this component to address anticipated need -?" waiting to announce a recall when it has sufficient parts on hand to execute the campaign. It is strongly recommended that you file an NHTSA complaint for this issue and limit driving until the problem is rectified either independently or under the auspices of a recall campaign. The passenger side rear drag link has not yet completely separated from the subframe but is likely to do so soon which can result in an accident or loss of control as this critical suspension link is responsible for maintaining steering direction of the right rear wheel.

- Yarmouth Port, MA, USA

I took my vehicle in for a state inspection and was informed the rear subframe was rusted/rotting and on the verge of detaching. Had this happened while driving, the results could have been catastrophic. The vehicle cannot be driven until this $4K dollar repair is completed. Upon speaking with the mechanic, this is a well known issue within Mercedes. Had I not asked for an alignment, this would have remained undiscovered until it inevitably broke off while driving the vehicle. This is a major safety issue and a safety recall should be issued.

- Newtown, PA, USA

Rear subframe failure caused me to loose control of vehicle almost resulting in a serious highway accident. Rear driver side stabilizer subframe mount was completely corroded and broken away from the subframe. There is no other significant corrosion on the subframe. MB claim normal corrosion however the pictures tell a different story.

- Mount Prospect, IL, USA

While performing service inspection, technician found REAR SUB FRAME RUSTED AND READY TO BREAK. Told they needed to show me the problem on the lift, as it was a serious SAFETY ISSUE and should be IMMEDIATELY REPLACED. Dealer and service acknowledged that this is a KNOWN and WIDESPREAD PROBLEM in C Class vehicles. Cost to replace quoted at $4200. No warning - thankfully inspection found before I was in a serious accident! Mercedes should issue recall for failed/corroded frame. Not the "safe" vehicle that Mercedes claims. (Car has been dealer serviced regularly, garaged, and 34,000 miles.) Owners shouldn't have to suddenly come up with $4,200 in order to drive their seemingly normal car. DANGEROUS.

- Cincinnati, OH, USA

The rear subframe rusted through causing mounting point of the torque link to fail. As a result, the car looses control when braking going sideways. Luckily, I discovered it when testing brakes after pad replacement in a safe setting. To my understanding, there are many other W204/W212 cars affected in the US with that issue. Mercedes so far does not want to take responsibility and recall cars for this issue which is a huge concern.

- Fairfax, VA, USA

The rear drivers side had a loud chunking/clanking noise while driving and the vehicle was unable to control and break when in motion. Driving was impossible as the breaking component was a total failure and car could not be controlled while traveling down 45-50mph zone. I reduced my speed to 20-25 mph by letting off on the gas to get better control of the car if breaking would need to be suddenly made. I relied on the shoulder to pull off if any sudden breaking was needed. The car was immediately take to be reviewed by a specialized Mercedes benz mechanic and further inspection proved that the rear subframe on the driver-??s (left) side was corroded and broken. The connecting arms are rusted, corroded and rendered the car inoperative. I notified my insurance company as well as car manufacturers corporate office. I researched this issue further and discovered that this reoccurring issue with this make and model. There are a pheletera of recounting of this same issue on various message boards to validate the same issues and callouts I found. The car was taken to the dealership that it was purchased and further inspection showed that the left side subframe/ subframe arms were corroded with rust and broken. The brake lines and fuel tank were equally rusted and corroded. The service manager confirmed that this is defect of the car but it had been part of a recall. I had the car towed for 2nd opinion to another dealership service department to access the car and this callout further validated the corrosion and rust was wide spread and has rendered the car inoperable unless these damages were fixed.

- Voorhees, NJ, USA

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

- The Plains, VA, USA

Driving low speed in town in fair weather and hit brakes, noise and strange "looseness" in back end. Had nearby service station inspect and rear sub frame had rusted out, searched and found multiple reports of exact issue. Confirmed w/ local mb dealer known issue and they are seeing about 1 month now.

- Charleston, WV, USA

The rear subframe has corroded around the areas where the trailing arm and control arm meet the subframe on both sides of the vehicle, and has disintegrated around the drivers side rear trailing arm causing it to have detached, along with a piece of the subframe. The metal of the subframe is distorted around the area of the break. The detached trailing arm and piece of subframe are now making contact with the fuel tank as well. The fuel tank could have easily ruptured and ignited when this car was still in operation, as this car was driven for several days before the manufacturing defect was discovered. The failure happened when coming to a gentle stop from 20-30 miles per hour on a straight road. There was a loud snapping noise from the drivers side rear. This car had 92,000 miles at time of the structural failure and has been regularly serviced, exclusively at Mercedes-Benz. Mercedes-Benz usa customer service is unable to offer any assistance. This exact issue has led to a recall of the same model in Canada, and there are countless NHTSA reports describing similar structural failures. Mercedes-Benz usa is aware of this issue and is also aware that there is a recall in Canada, but has made it clear that goodwill will not be extended.

- Huntington, WV, USA