Subframe on W212 rotted

[KellyMK]

Hello All

I just git news my rear subframe cross member on my 2010/E350 has been ripped/fatigued and the MOT guys said they have never seen anything like this on a car this age...wouldnt be so bad had I not just replaced the gearbox and TC..anyone offer some advice please

 

[Steve@Avantgarde]

No advice other than its a common issue on the W212/W204/W171.

 

[KellyMK]

No advice other than its a common issue on the W212/W204/W171.

Thanks

 

[vtaylor78]

Sorry to hear this , not the news you want.
I have heard of this happening to a fair few now around that age.

 

[Gazwould]

Ordering XCP and Jenolite as we speak .

 

[Wighty]

Whenever I read one of these I want to go and spray another can of Dinitrol into my rear subframe . Except I did it only a few weeks ago so I’ll have to wait

 

[Rory]

Is MB replacing them on W212's?

ETA: Member here got one covered by MB recently but he'd only bought the car from a dealer (I think non-MB) 2 mths prior: https://forums.mercedesclub.org.uk/...ew-guy-and-also-1st-merc.186296/#post-1883416

 

[star]

Oh no, rusts from inside.

 

[mioba]

rusts from the inside. press mb under the 30yr perforation warranty

 

[Exp21]

Are there some specific points to look at that fail usually? Pics are unbelievable..

 

[_inalbion]

..add mine to the ever growing list - 2010 E class @100k

suddenly found myself whilst braking also pirouetting into on coming traffic yeta.

Nice.

 

[Peterbrake]

Wow that’s dreadful and it’s got me thinking, I have a 2013 CLS shooting brake and I’m sure I read somewhere that it is based on an E class, if that is so should I start to worry?

 

[mioba]

Wow that’s dreadful and it’s got me thinking, I have a 2013 CLS shooting brake and I’m sure I read somewhere that it is based on an E class, if that is so should I start to worry?

worry brings you no where. Get under the car and have a poke about.

 

[mioba]

..add mine to the ever growing list - 2010 E class @100k

suddenly found myself whilst braking also pirouetting into on coming traffic yeta.

Nice.

Get to a merc dealer they at first. They Are changing some for free

 

[Peterbrake]

I know where you’re coming from Mioba but if it’s rusting from the inside it will be too late when it’s apparent. Does anyone know if CLS SB subframe is the same as an E class?

 

[AnthonyUK]

Wow. That is as bad as BL in the 70s level of corrosion.

 

[charlysays]

I know where you’re coming from Mioba but if it’s rusting from the inside it will be too late when it’s apparent. Does anyone know if CLS SB subframe is the same as an E class?

No there should still be signs before it fails catastrophically under normal driving conditions. If you took it on a track or something then yes it may be harder to catch before it fails seriously ... but for normal driving there will be weak spots/ pinholes evident long before it rips apart like the above pics. A lot of that metal has actually vanished so this could have been spotted before absolute failure but hasn't because people assume a bit of rust is just due to stone chips.

Clean it down once a year thoroughly in that area. Using a bright light look for any rust spots. Use a hammer and a hammer through screwdriver or maybe even something like a 3mm flat end punch to beat on those spots. If the metal deforms inwards you know it's time to change it.

Yearly wax injection with dinitrol/ bilt hamber dynax should prevent this issue but it looks like there might be a lot of cars around festering away by now.

The only thing on the W202 which does this is the front lower controls arms. They can snap near the ball joint but once again it's easy to spot/ prevent before serious failure if you know what to look for.

 

[Peterbrake]

Thanks Charlysays, good advice you’ve put my mind more at rest.