2011 Mercedes-Benz C 300 Suspension Problems

Subframe rusted resulting in failure of left rear suspension mount causing dangerous loss of control of car under braking.

NHTSA ID

11623710

Incident

Oct 28, 2024

I just purchased a 2011 Mercedes C300. I was told that for the past 2-3 years the vehicle would constantly bald out the rear 2 tires and would need replaced every 3 months. As I was driving the vehicle I noticed that the rear tires would make weird noises as if it was hutting something. Upon further investigation the rear sub frame is rotted, which based on research appears to be a very common problem with these vehicles. The rear sub frame is rotted in which caused the lower control arms to completely rot off of the frame posing as a serious safety issue for me when driving with my children and a safety issues for others when I drive on the road. On top of that due to the lower control arms completely rotting off the frame it caused the control arms to hit the gas tank which could catch the car on fire. Mercedes has refused to issue this as a recall in due part to their negligence. Customers cannot afford to pay $5000 for a rotted subframe due to negligence from Mercedes. Please research how many vehicles have had rotted subframes for this vehicle. In Germany they will repair the rotted subframe free of charge. Mercedes needs to be held accountable for risking peoples lives.

NHTSA ID

11618212

Incident

Oct 4, 2024

Recently I was driving and heard a knocking/creaking noise in the left rear. When braking I felt as though I was going to lose control of the vehicle...vehicle appeared to fishtail and pull to the left. I first noticed it on [XXX] when I was driving on the highway in excess of 60 MPH. On [XXX] I brought it to my mechanic (Genesee Auto Repair, 40 Liberty Street, Salem, NH (603)898-1899) and my mechanic informed me that the left rear subframe had rotted out and told me that I should not be driving the car. There were no warning lamps or messages indicating there was a problem. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11581865

Incident

Mar 29, 2024

Non operating. No tags . No plates.

NHTSA ID

11571578

Incident

Jan 31, 2024

The subframe has rusted/fallen off. This is incredibly risky as the car cannot be driven safely and it happened without warning. My mechanic said it is not due to any driving incidents but through rust occurring on Mercedes' subframes, which are flimsy. It has been inspected professionally by a mechanic. There are NO warning lamps. This could kill someone on the highway as while braking the car veered left and right. I had small children in the car we all neck pain from the car veering while stopping on the highway. I have taken good care of my vehicle and have all maintenance current. This is a fault with the material on the subframe. For MB: All the subframes are on backorder and are incredibly expensive to fix. I have a video of the damage from the mechanic if needed.

NHTSA ID

11553395

Incident

Sep 1, 2023

2011 C300 4matic Sport I'm very concerned about the front subframe after going over the invoice and everything that was replaced on the rear subframe due to a recall Mercedes issued. But wait doesn't the whole subframe have severe rust corrosion all throughout yes it does per mechanic/technician. I'm having steering issues while driving the vehicle when applying the breaks the vehicle pulls very hard to the left the whole car swerves to the left very dangerously. After getting it checked out the mechanic/ technician pointed out that the control arm snapped from the Front subframe due to severe corrosion. I'm not understanding how the recall was only for the rear subframe only. The whole entire subframe is severely rusted. Front subframe which may experience premature wear of the front axel carrier and a fracture risk, potentially resulting in sudden loss of steering control. After internal endurance testing determined the front axle carrier supplied for certain Mercedes SUV’s and cars may weaken prematurely. An investigation revealed the root cause of the problem was due to a manufacturing defect in which the parts did not receive proper corrosion protection. My front subframe did not receive the proper corrosion protection. It's available for inspection. It's currently still at the dealership due to being unsafe to drive. I'm having steering issues while driving the vehicle when applying the breaks the vehicle pulls very hard to the left the whole car swerves to the left very dangerously. The problem has been reproduced or confirmed by a dealer or independent service center. The vehicle or component has Not been inspected by the manufacturer, police, insurance representatives. Only Dealer and independent service center did the inspection. No warning indicators no other symptoms, this issue took place around February - March of 2023. When I received the letter about the subframe recall I was excited thinking the issue would be fixed. But No it's unsafe

NHTSA ID

11539978

Incident

Feb 1, 2023

Like apparently the majority of this model year C300, the rear subframe is completely disintegrated. This is a known issue but Mercedes has not communicated it nor fixed it. I was told, and as the photos clearly indicate, this very likely could have resulted in a catastrophic or fatal accident as the entire rear is corroded. I have photo and video support as well as the inspection from a mechanic.

NHTSA ID

11517129

Incident

Apr 7, 2023

Car slow down and stop and cannot start in traffic….

NHTSA ID

11514093

Incident

Mar 22, 2023

My vehicle has been making very odd noises, the steering wheel keeps looking off center and the car is kicking/fishtailing at times without warning. Our mechanic has looked at the car SEVERAL times and finally discovered that the sub frame is completely rusted out and broken. We were told not to drive the vehicle anymore as it is extremely dangerous. After researching about this issue, we found that a class action lawsuit was filed in February 2023 for corrosion/rusting out of frames in 2010-2022 Mercedes Benz models. According to the information, Mercedes is refusing to cover the cost of the repairs and is not returning calls from customers effected by this issue. This information has been reported and added to the class action lawsuit. It was recommended that we report it here as well.

NHTSA ID

11512961

Incident

Mar 20, 2023

Rear tires were down to steel belt after replacing August 1, 2022 and less than 10,000 mile wear. I took the car to a dealership for diagnosis. The rear subframe is completely corroded and failed causing extreme wear on tires and a DANGEROUS DRIVING SCENARIO. I’ve researched and see this is a common problem on these Mercedes cars. Why is there no Mercedes recall or accountability for this common issue?This is a serious issue that could cause serious accidents and bodily harm or death..

NHTSA ID

11506266

Incident

Feb 8, 2023

My 2011 c300 has a rotted rear subframe making the car not able to be driven. It has major ,life threatening, costly damage and this issue already has a recall all over the world but not in the United States.

NHTSA ID

11503537

Incident

Jan 24, 2023

Rear sub frame and suspension welds have cracks and are broken a loose which when having to put on brakes suddenly cause car to servely pull and twist which can cause a bad accident or worse.

NHTSA ID

11502894

Incident

Nov 14, 2022

The contact owns a 2011 Mercedes-Benz C300. The contact stated while driving approximately 60 MPH, the brake pedal was depressed, and the rear end of the vehicle pushed out. The contact looked underneath the vehicle and noticed that the subframe was rusted. The vehicle was taken to an independent mechanic who informed the contact that the control arm had detached. The contact called the local dealer, but the vehicle was not diagnosed or repaired. The manufacturer was contacted but no additional assistance was provided. The failure mileage was approximately 105,000.

NHTSA ID

11501116

Incident

Dec 23, 2022

Mileage

105,000 mi

I was teaching my 16 year old son how to drive when he got his learners permit . When we got onto the highway a car cut him off and he had to apply a firm steady brake . When breaking the car swerved from the rear into the other lane , nearly striking another vehicle . This also resulted in a loss of control when applying heavy breaking after I had him pull over and I took control of the vehicle once I was able to get the car to the shop I pulled the rear wheel s off and inspected the brakes , which were found to be in good condition . I looked around the vehicle and noticed where the rear driver side subframe connected to the control arm broke off from a manufacturer defective weld or poor selection of materials . component. Upon inspection both sides are perforated and have lost structural integrity. Many other vehicles of the model type have reported similar issues online. This is a serious safety concern that will happen to 100% of these vehicles. A recall needs to be issued by Mercedes for this immediately. This vehicle has very little rust anywhere except at these connections .

NHTSA ID

11499607

Incident

Dec 30, 2022

The contact owns a 2011 Mercedes-Benz C300. The contact stated that while driving at an undisclosed speed, the rear driver’s and passenger’s side wheels swayed left to right, and the rear driver’s side wheel detached from the suspension. No warning light was illuminated. The vehicle was taken to a repair shop where it was diagnosed that the rear subframe was rusted and needed to be replaced. The dealer was notified of the failure and the contact was scheduled an appointment. The manufacturer was notified of the failure and the contact was awaiting an estimate. The contact was provided a case number. The failure mileage was 88,640.

NHTSA ID

11499171

Incident

Dec 24, 2022

Mileage

88,640 mi

Tried to get alignment and was told rear sub frame is rotted. Must be replaced. Car is garaged. Serviced at dealer. This shouldnt be happening. Car was involved in accident (mainly passenger doors damaged) which triggered us to need to get new tire which alerted us to alignment cant be completed and told to not drive car it's not safe due to rotted subframe.

NHTSA ID

11496482

Incident

Oct 1, 2022

The subframe and the brake lines are very faulty in this car when it comes to its design. The subframe and brake lines rust easily and are cheaply made for this car. My car break down while driving making it hard to have pressure on the brakes. My incident was around the school area. There were no accidents or collisions Involved. It could happen to adults and children. The dealer never confirmed this problem before selling it to me. Another manufacturer told me about this problem. The car showed warning signs like the braking system and brake fluid. The brake fuel was leaking. The problem appeared when I started the car.

NHTSA ID

11495007

Incident

Nov 18, 2022

I was driving my 2011 MB C300 40 MPH on a straight suburban road when the light turned red. I applied the brakes and heard a clunk from the rear. Surprisingly, the car swerved with a right turn yaw moment. Normally I enjoy driving my car, but that never happened before. So I tried it again in the next block and it yawed again. That’s not right. My mechanic happened to be just down the road so I pulled in. He told me that the rear subframe had rusted out and the car was unsafe to drive. Furthermore, he would not attempt welding it because the metal is too far gone. A new replacement part is unavailable from the dealership and back ordered from Germany for months. Used part will also be rusty. My car with 77k miles on it is suddenly worthless. Mercedes-Benz “The Best and then Nothing”

NHTSA ID

11493982

Incident

Sep 16, 2022

The rear subframe rotted and broke as I was driving. I almost got into a bad accident. This apparently is a common & deadly issue that MB is aware of. Unacceptable that there is not a recall.

NHTSA ID

11492864

Incident

Aug 14, 2022

While driving home last night (with passenger), I experienced a sudden pull to left and wobble\oscillation of the car when I made steering corrections to prevent vehicle from going into oncoming traffic. Car seemed to behave normally except whenever I applied the brakes. I proceeded home, where I inspected for the obvious such as brake calipers, pads. rotors etc. Then I removed the rear left tire. This was due to a clunking sound that seemed to come from that area. Everything looked OK until I saw a front lower suspension part (a plastic covered pressed metal strut connecting the lower part of the wheel\rotor assembly to large U-shaped frame member which had multiple welded attachments and brackets) just hanging there unattached on one (forward) end. The bracket it was bolted to was just sheared off. Looked like it rusted to the point of finally tearing itself off of the frame. There was no warning of this condition either by sensors/lights/etc. or the performance of the vehicle when driving it. The defective braking action was sudden. This is NO SMALL ISSUE! After reading of the numerous reports of this very same problem I have to say I am amazed that NOTHING IS BEING DONE TO PREVENT THE FIRST DEATHS AND INJURIES THAT WILL MOST LIKELY OCCUR FROM THIS. This is a danger to the occupants of the principle vehicle, pedestrians, as well as other vehicles in the immediate vicinity, moving or stationary. This can happen at high speeds, slow speeds, in traffic with other vehicles around the car or humans on sidewalks. I can clearly see that this is not a small repair as it looks like the entire rear assembly would need to be taken apart and reconstructed in order to replace the part. I have also read that this issue is not only common but that it has been recalled in Canada and Europe by Mercedes for repair. I guess we are waiting for the first deaths to occur before our American safety agencies can take action? Really?

NHTSA ID

11491541

Incident

Oct 29, 2022

Rear suspension crossmember mounting point for one of the control arms broke off allowing control arm to fail. Possible entire wheel assembly could now fail creating dangerous driving conditions especially at higher speeds. Took to a shop and confirmed. Called Mercedes dealership and they said it was not covered by a recall even though in Europe I believe it is. Many websites have said this is an ongoing and common problem.

NHTSA ID

11491255

Incident

Oct 7, 2022

I have a 2011 Mercedes C300 that I purchased as a Certified Vehicle - this car was purchased at The Mercedes Dealer in Kansas City. I believe I purchased it around 2013 - I have recently found out that the rear sub frame is completely rusted out. I have had the car repaired at my auto shop - Not a MB dealership, as there was not a dealership that was able to see the car in any reasonable amount of time and the car was not safe to drive. The only way I found out about this rusted out subframe was due to the control arm breaking off - This car was very dangerous to drive and in essence, it is probably a good thing that the control arm broke as this could have resulted in a loss of steering on the vehicle and a very dangerous accident! I have been reading online and speaking with MULTIPLE people who have had the same situation with this rear subframe. This is CLEARLY an issue with MB and clearly an issue that they have been made aware of. When I called the NMB service department they were a month out to just look at the car - and the part is on back order I was told - which CLEARLY indicates a lot of these rear sub frames are being replaced. I am attaching various articles / forums online that I just, at a glance, composed a list of. There are a TON of stories of these sub frames rusting out for various models. Seems to be tied mostly to the C300 vehicles. I am attaching pictures of this rusted out subframe and an invoice that I paid to have the car repaired for this issue. The ironic thing is when I was at this auto shop, there was another C300 sitting out front that had just had the same rusted out subframe replaced. Mercedes has a recall in Canada for this SAME issue and other countries have acknowledged this is a major safety issue. A rear subframe should not rust out and leave the driver with no way to steer the car. Mercedes has refused to acknowledge this is an issue in the US.

NHTSA ID

11491041

Incident

Sep 26, 2022

Rusted left rear ear of rear subframe.

NHTSA ID

11489990

Incident

Oct 19, 2022

Rear Sub frame faiIure / rusted and rotted On this site alone there are complaints listed under 3 different heading Structure (30) / SUSPENSION (38) / UNKNOWN OR OTHER (20) all related to the rear sub frame. not to mention 100's on the web. I nearly died when I hit the brakes the car lurched to the left at highway speed. My mechanic told me that the rear Subframe was rotted and the rear control arm is no longer connected to the sub frame He insisted that the car is UNSAFE to drive. He was very surprised as the car only has 70,000 miles on it and in good shape with no rust anywhere else on the car. I did a quick search of the issue on the web and immediately found that MB has had this issue across the world in various models manufactured in 2011-2014. Presently, there are recalls in Germany and Canada for this issue. I contacted my MB Service department and was informed that no recall for this issue exists in the US and they would not cover the costs to repair. The repair could cost between $5k to $7k They told me that I would need to contact MB North America Customer Service. I find it amazing that MB Service, Dealers and North America HQ are all aware of this issue but the Company will not issue a recall or stand behind their product. This not some minor defect. When a major structural component of the car is compromised the lives of vehicle occupants and others on the road are at risk of death due to a major accident. The vehicle is now undriveable and will cost several thousands of dollars to repair. MB is fully aware of this issue and refuses to do anything about it. NHTSA needs to address this issue and make the Manufacturer stand behind their Quality pledge which as a consumer you are paying for when purchasing what you expect to be exceptional German engineering and what you are given is a a product with a known defect that will not be addressed.

NHTSA ID

11489986

Incident

Aug 2, 2022

What component or system failed or malfunctioned, and is it available for inspection upon request? Rear subframe has rusted out and left side arm has separated- my car has been routinely maintained and primarily housed in garaged parking. It does not have a history of flood or water damage. How was your safety or the safety of others put at risk? My steering and breaking was impacted even at low speeds < 30 MPH. Has the problem been reproduced or confirmed by a dealer or independent service center? - Vehicle failed a Maryland state safety inspection and was deemed unsafe to drive. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Yes, inspected by Maryland state certified safety inspector Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? I noticed decreased accuracy in my steering upon breaking and decreased function in breaking- my inspection revealed that all breaks were intact and working.

NHTSA ID

11489493

Incident

Oct 9, 2022