Sub Frame Severe Corrosion
Thread Starter
Newbie
Joined: Mar 2026
Posts: 3
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Sub Frame Severe Corrosion
My 2016 c450 AMG just went into the Mercedes Dealership. They have responded with their findings which included a detailed verbal and video description.
The video shows corrosion and cracks along the subframe on both sides. The service report states, "completely broken right-side rear subframe and the left side is also showing signs of imminent failure".
Additionally, they are recommending the following:
Repair or replacement of the rear subframe.
Repair or replacement of the rear flex disc due to large tears.
Reseal of the transfer case to address oil leaks.
Replacement of the pinion oil seal to address oil leak.
Reseal of the upper timing case to address oil leak.
Replacement of the transmission oil pan gasket and transmission service.
Reseal of the cam covers to address oil leaks.
I have been advised by my service rep that the 2016 C450 is not covered by the recall or warranty.
NEED HELP AND SUGGESTIONS
The video shows corrosion and cracks along the subframe on both sides. The service report states, "completely broken right-side rear subframe and the left side is also showing signs of imminent failure".
Additionally, they are recommending the following:
Repair or replacement of the rear subframe.
Repair or replacement of the rear flex disc due to large tears.
Reseal of the transfer case to address oil leaks.
Replacement of the pinion oil seal to address oil leak.
Reseal of the upper timing case to address oil leak.
Replacement of the transmission oil pan gasket and transmission service.
Reseal of the cam covers to address oil leaks.
I have been advised by my service rep that the 2016 C450 is not covered by the recall or warranty.
NEED HELP AND SUGGESTIONS
Senior Member
Joined: May 2004
Posts: 474
Likes: 36
From: Central Ohio
2017 C43, 1966 230SL, 2006 Jeep Rubicon
IDK what would cause that. Maybe ocean (salt) flood water? Maybe a poorly repaired rear end collision? Sorry to hear about that situation, I don't have any advice on how best to proceed.
MBWorld God!
Joined: Dec 2019
Posts: 32,217
Likes: 6,275
My 2016 c450 AMG just went into the Mercedes Dealership. They have responded with their findings which included a detailed verbal and video description.
The video shows corrosion and cracks along the subframe on both sides. The service report states, "completely broken right-side rear subframe and the left side is also showing signs of imminent failure".
Additionally, they are recommending the following:
Repair or replacement of the rear subframe.
Repair or replacement of the rear flex disc due to large tears.
Reseal of the transfer case to address oil leaks.
Replacement of the pinion oil seal to address oil leak.
Reseal of the upper timing case to address oil leak.
Replacement of the transmission oil pan gasket and transmission service.
Reseal of the cam covers to address oil leaks.
I have been advised by my service rep that the 2016 C450 is not covered by the recall or warranty.
NEED HELP AND SUGGESTIONS
The video shows corrosion and cracks along the subframe on both sides. The service report states, "completely broken right-side rear subframe and the left side is also showing signs of imminent failure".
Additionally, they are recommending the following:
Repair or replacement of the rear subframe.
Repair or replacement of the rear flex disc due to large tears.
Reseal of the transfer case to address oil leaks.
Replacement of the pinion oil seal to address oil leak.
Reseal of the upper timing case to address oil leak.
Replacement of the transmission oil pan gasket and transmission service.
Reseal of the cam covers to address oil leaks.
I have been advised by my service rep that the 2016 C450 is not covered by the recall or warranty.
NEED HELP AND SUGGESTIONS
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,151
Likes: 1,765
From: Colorado
G550
OP didn't indicate his location, but I grew up in the northeast where salted roads in the winter would destroy a car in 6 years. Best solution is to buy a junker to drive during salt season and keep the lux car stored.
Junior Member
Joined: Jul 2025
Posts: 48
Likes: 8
2020 AMG C 43
I was gonna sell my 2013 Sonata that has 60k miles on it when I got my c43. They wanted like 5k for it... Pshh now its my winter beater. Chicago weather is brutal.
That sucks with all the oil leaks. I think they are well known for our cars. Go to a reputable euro mechanic and get it all serviced if you want it to last.
Thread Starter
Newbie
Joined: Mar 2026
Posts: 3
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Estimate for all the work from Mercedes shop came out to $16K! Going to reach out to representative of Mercedes North America.
I do live in the DC area so salt could be a factor but still think it should be covered as a defect.
I do live in the DC area so salt could be a factor but still think it should be covered as a defect.
MBWorld Fanatic!
Joined: Feb 2017
Posts: 2,296
Likes: 1,204
From: Baltimore County, MD
'13 s212 63 p30. '06 LX470
A subframe itself is not expensive (600plus). Save yourself at least half on the labor at an Indy. The dc area gets lots of brine which is very sticky and regular undercarriage washes are needed. For long term performance consider fluid film or the like. One of my vehicles is an 06 and still minty fresh underneath due to fluid film. That vehicle is known for rust. If you want to undertake protecting a frame, lmk.
I found a fantastic new independent in the Westminster Md area if you are interested…though not cheap, but cheaper than a dealer. Lmk
or if you are closer to modern masters, hit them up
I found a fantastic new independent in the Westminster Md area if you are interested…though not cheap, but cheaper than a dealer. Lmk
or if you are closer to modern masters, hit them up
Last edited by Baltistyle; Mar 27, 2026 at 09:15 PM.
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MBWorld Fanatic!
Joined: Feb 2017
Posts: 2,296
Likes: 1,204
From: Baltimore County, MD
'13 s212 63 p30. '06 LX470
Mercedes specialists. Tell them Gary with the wagon that was recently there recommended them. I uh…erased my transmission and clutch coding with a launch creader (i’ll have a thread on that ) and they got me going again for a very inexpensive price of one hour labor. YMMV.
