Mercedes-Benz C300 ball joint problems

Filed Oct 24, 2026 · Suspension · OH

Vehicle: 2016 Mercedes-Benz C300, VIN [XXX], approximately 52014 miles. Purchased Certified Pre-Owned in 2017. All maintenance performed at authorized Mercedes-Benz dealerships. On XXX, during a routine B-Service at Mercedes-Benz of Easton ([XXX]), the technician found that the rear subframe (rear axle carrier) was rusted and perforated. The corroded area is located directly above the rear control arm. The technician stated on a recorded inspection video that the corrosion would continue to spread around that area until the control arm disconnects, and described it as a safety hazard. He recommended replacement of the part. Photos and video (technician shared video link - [XXX]) were taken during the inspection and are available. I was not notified of any corrosion in this area during previous dealer services, and the vehicle showed no symptoms that I noticed before this inspection. I am concerned that a structural suspension mounting component has corroded through on a vehicle of this age, and that if the control arm separates from the subframe, it could cause loss of control. I am reporting this so that the federal safety agency can determine whether it is a wider problem on this model. No crash, injury, or fire has occurred. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 10, 2025 · Airbags, Suspension · MA

Due to the corrosion in the rear subframe both side of lower control arms snapped the tires to the car are wearing out due to the corrosion in rear subframe and it’s was also hitting my gas tank if I was to go over any holes which can cause a bigger issue

Filed Jul 7, 2025 · VA

Upon purchasing my 2016 C300, I starting experiencing a right pull whenever I press on the brakes. I was very concerned as I use this vehicle to assist with dropping and pick up of my 2 grandchildren. The more I drove the car, the more unsafe especially when I attempt to bring my car to a stop. I took the car to a local mechanic and I was advice to take it to a Mercedes dealership. The mechanic also advice that it was an issue with the REAR SUB FRAME. A week later I took the car in to Mercedes as suggested and a day later I received a call and video from Mercedes that the subframe was broken and that is why I am getting that hard pull whenever I brake. Mercedes also stated that the control arm bracket is barely on and it is causing the vehicle to flex.

Filed May 29, 2025 · Suspension, Transmission · CT

Rear-subframe corrosion at the lower-control-arm mounts has progressed to the point where both arms have play and produce loud metallic bangs while braking or turning at low speed. Two independent shops lifted the car, documented flaking rust around the bushing sleeves, and advised the subframe is structurally compromised and could let a control arm detach under load. The corroded subframe remains installed and can be inspected on request. Safety risk: a detached rear control arm would cause sudden, unpredictable steering and loss of control. The vehicle already pulls right under braking, and feels very unstable in curves Problem has been reproduced and photographed by two independent repair facilities. No manufacturer representative has inspected the vehicle so far. Additional component failures possibly linked to the same progressive chassis stress: premature wear of both front CV axles; timing-chain stretch with worn guides; slack oil-pump chain; upper & lower oil-pan gasket leaks; water-pump seepage; right engine-mount collapse; persistent misfire traced to a loose intake-hose clamp; transmission-cooler hose clip released under pressure, dumping all ATF and destroying the automatic transmission; excessive play in all four lower control-arm bushings. The transmission and the other components were replaced 1-2 months before the subframe bro History: A faint clank from the rear suspension first appeared roughly three years into ownership. Dealer service dismissed it as “normal noise,” and warranty would not cover “loud clanks,” so the issue went unaddressed. The noise has grown steadily into the current condition, suggesting long-term subframe corrosion that was never inspected or remediated. No collision, flood, or off-road use; the car has typical Northeast winter-salt exposure. The failure pattern matches subframe-corrosion cases already acknowledged by the manufacturer on this model, although this serial number is not yet included in the official campaign.

Filed Oct 5, 2024 · Suspension · OH

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.

Filed Sep 16, 2024 · Body, Brakes · IN

On several instances of breaking, my 2013 Mercedes Benz C300 pulls hard to the right and becomes very unstable. I assumed it was a brake problem by the way the car drove. I took it to my mechanic, who immediately identified the rear subframe had rusted so much that a control arm had broken loose from the subframe. The rear subframe acts as a foundation for the rear suspension and holds the backend together. Fortunately I was able to get this diagnosed prior to a serious accident. The car gets very unstable, especially at higher speeds, when braking. There are no warning lights that will catch this. This problem absolutely places both passengers and other cars on the road at risk of a collision when braking, especially on the highway at higher speeds. I am going to contact a local Mercedes Benz dealer to evaluate replacement of the damaged parts to ensure the car is safe to drive following repair. Based on the links below, it sounds like a known issue at Mercedes Benz. I was never notified of any issues or from prior service visits, or via mail notice from the manufacturer. My mechanic was shocked, to say the least. Hoping MB will take care of this dangerous problem without hassle. See: [XXX] [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jan 16, 2024 · Suspension · WI

Drivers side lower control arm was rusted off rear subframe causing vehicle to be inoperable.

Filed Sep 3, 2023 · Suspension · MA

Excessive rust has caused a separation of the lower control arm from the rear sub frame. From Google searches this appears to be a common safety defect in the manufacturing of these vehicles. Control arm separation causes drive ability and stability issues that can lead to loss of control of said vehicle leading to accidents that can cause serious bodily injuries including death. Why hasn't Mercedes been forced to recall the affected vehicles in the United States as they have been in several other countries?

Filed Aug 22, 2023 · Body, Suspension · OH

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

Filed Aug 1, 2023 · Suspension · NY

Rear subframe rust through, affecting the function of control arm. When braking mildly caused the forward motion of vehicle to swerve into oncoming traffic. It has been reported and is in their possession. There was a small clicking noise like a possible loose shock absorber, a few times in the past month. Then two days ago, the sound became stronger including a clicking noise like two pieces of sheet metal torn passing each other. Upon personal inspection I found severe rust through on the subframe on the left side in front of the left drivers side rear tire. Corporate has sent a letter extending the warranty for that part. Photos can be provided.