Update with scary picture - W204 2008 rear subframe failure

[Em13]

So the rear subframe of my SLK completely failed on Saturday night. This caused me to lose control completely of my vehicle. Luckily I managed to stop it, but believe me it was very close to ending horrifically...reading posts around this I’m concerned there’s a trend. My MOT was carried out in March with no advisories. Serviced in January. My garage are shocked and upset about this, as there was no sign of corrosion and they believe it’s corroded on the inside. How can this happen and be ok? Any idea if I’d be able to take this further with Mercedes?

 

[John Laidlaw]

So the rear subframe of my SLK completely failed on Saturday night. This caused me to lose control completely of my vehicle. Luckily I managed to stop it, but believe me it was very close to ending horrifically...reading posts around this I’m concerned there’s a trend. My MOT was carried out in March with no advisories. Serviced in January. My garage are shocked and upset about this, as there was no sign of corrosion and they believe it’s corroded on the inside. How can this happen and be ok? Any idea if I’d be able to take this further with Mercedes?

Omg.....

 

[00slk]

You were certainly lucky...Or unlucky as is the case.
This is a common thing for rust to be ripe on the inside of many chassis and frames, it eats away hidden to the naked eye and can go years undetected until something like this happens. I used to do test inspections and in the old days we could or did use a picking hammer to tap certain parts of the under frame that can or has proven to be a usual rust prone area. Nowadays one can not do any sort of thing or remove covers for more safer inspecting. It does have its draw backs!

 

[JBell]

So the rear subframe of my SLK completely failed on Saturday night. This caused me to lose control completely of my vehicle. Luckily I managed to stop it, but believe me it was very close to ending horrifically...reading posts around this I’m concerned there’s a trend. My MOT was carried out in March with no advisories. Serviced in January. My garage are shocked and upset about this, as there was no sign of corrosion and they believe it’s corroded on the inside. How can this happen and be ok? Any idea if I’d be able to take this further with Mercedes?

That is horrific!!!!!

 

[LostKiwi]

Thats pretty horrendous.
Hopefully MB will do something on the basis of their anticorrosion warranty.

 

[Zareh]

I am in a very similar situation as well, my 2008 C300 RWD (113k miles) subframe snapped at the rear right most likely due to the visible rust/corrosion around it. Happened to me while driving as well, freaked me out. I took it to the local benz dealership here in Massachusetts this morning got quoted at $4k to fix.

Unfortunately, I bought the car from a family friend two years ago so no CPO warranty from the local dealer. Brought up the 30-year anti rust and got directed to go through MB USA. Gave them a call this afternoon and had my information taken down. Expecting a call from the "highest level of contact within 24 hours" as to whether or not MB will help/cover.

Really hope they don't shaft me because at $4k, the cost is at least half the value of the car at this point.
If I get no help, my mechanic has suggested we plasma weld a steel plate across the break to secure the rear right. I've heard this might be an even stronger fix and much cheaper/faster to fix.

What do you guys think of my odds here?

 

[Jim2]

The point is, why are they rusting so badly??? I remember 1980's MK4 /5 Ford Cortina front sub-frames, and even today, plenty of those cars around.....but no rust issues with the sub-frames ( might be cosmetic rust, but that's not a serious issue...) ??? Has to be a problem in the metal composition or the protective coating ( or most likely both!!! )

 

[LostKiwi]

That's three we've heard of in the past month - all comparitively young cars.
I spot a US class action and recall coming up...

 

[Em13]

That's three we've heard of in the past month - all comparitively young cars.
I spot a US class action and recall coming up...

I fully agree...in fact I sold my car for spares or repair, then I thought “hang on, this isn’t right!” I’ve fully maintained this car and it shouldn’t happen, full stop. I’ve since been looking for a runaround until this is resolved, thousands of cars older, double the mileage and “poorer” quality cars (supposedly!) that seem to be fine, this is just not ok from any car...let alone a high quality one such as this.
Mercedes wanted me to pay to get it looked at by them (recovery to their garage etc)...already saying they would’nt cover costs it as it wasn’t seen by them since 2012, despite it being fully serviced since by an MB specialist indie garage. I’m not prepared to pay anything as already paid £117 to have it recovered once.
I’ve since gone to the new VOSA here in then UK, as it feels this is wrong, rather than a lack of maintenance/observation by my mechanic etc. Hope I help raise the profile of this, as I certainly would never buy one again!!

 

[Em13]

Also I nearly sold the car a month ago, just passed its MOT, recently serviced. I’m so glad it was me, not someone else, who went through this. It sends shivers down my spine and the “what ifs” will haunt me forever, despite none of this being my fault. Let’s hope we get some answers...

 

[Matthew Hemmings]

Also I nearly sold the car a month ago, just passed its MOT, recently serviced. I’m so glad it was me, not someone else, who went through this. It sends shivers down my spine and the “what ifs” will haunt me forever, despite none of this being my fault. Let’s hope we get some answers...

 

[Matthew Hemmings]

My car is in at the moment having the sub frame done under the corrosion warranty,they rang this morning to say that the brake lines are corroded as well.
I did have an advisory on the last mot.they have said it will cost £250 to replace them,as at the moment the sub frame is dropped out.and it would need to be removed again to fit the lines as they will eventually need replacing,and it won't get an mot the way they are.which I was aware of .it's been a two day repair for the subframe so far. And Mercedes labour charges are £130 an hour last time I checked,so I've told them to do them.the subframe was 840,plus two days labour,by my rough reckoning,this job is running well into £2000.and running into a third day. And they have given me a brand new amg a class as a courtesy car.so all in all,they have looked after me well.

 

[Capra]

My car is in at the moment having the sub frame done under the corrosion warranty,they rang this morning to say that the brake lines are corroded as well.
I did have an advisory on the last mot.they have said it will cost £250 to replace them,as at the moment the sub frame is dropped out.and it would need to be removed again to fit the lines as they will eventually need replacing,and it won't get an mot the way they are.which I was aware of .it's been a two day repair for the subframe so far. And Mercedes labour charges are £130 an hour last time I checked,so I've told them to do them.the subframe was 840,plus two days labour,by my rough reckoning,this job is running well into £2000.and running into a third day. And they have given me a brand new amg a class as a courtesy car.so all in all,they have looked after me well.

So at least you are saving money having the brake lines chsnges at the same time. The hourly rates are crazy these days.

 

[alexanderfoti]

My car is in at the moment having the sub frame done under the corrosion warranty,they rang this morning to say that the brake lines are corroded as well.
I did have an advisory on the last mot.they have said it will cost £250 to replace them,as at the moment the sub frame is dropped out.and it would need to be removed again to fit the lines as they will eventually need replacing,and it won't get an mot the way they are.which I was aware of .it's been a two day repair for the subframe so far. And Mercedes labour charges are £130 an hour last time I checked,so I've told them to do them.the subframe was 840,plus two days labour,by my rough reckoning,this job is running well into £2000.and running into a third day. And they have given me a brand new amg a class as a courtesy car.so all in all,they have looked after me well.

Out of interest. Does your car have a full MB SH?

 

[JBell]

Out of interest. Does your car have a full MB SH?

https://www.honestjohn.co.uk/askhj/...o-court-over-their-30-year-bodywork-warranty-

 

[alexanderfoti]

https://www.honestjohn.co.uk/askhj/...o-court-over-their-30-year-bodywork-warranty-

I know about that, but its good to know if they just "do it" when presented with the car; rather than fight the whole way.

 

[JBell]

I know about that, but its good to know if they just "do it" when presented with the car; rather than fight the whole way.

I know, as I drive an 8yo W204 not entirely happy about the failures!!!

 

[Matthew Hemmings]

https://www.honestjohn.co.uk/askhj/...o-court-over-their-30-year-bodywork-warranty-

It had a full Mercedes service history until 50K,then and independent Mercedes specialist history since.the car has 67K on the clock.and I bought it from Mercedes Swansea,who sold it new,then sold it to me when it came back in as a part exchange with 42K on the clock.

 

[Matthew Hemmings]

So the rear subframe of my SLK completely failed on Saturday night. This caused me to lose control completely of my vehicle. Luckily I managed to stop it, but believe me it was very close to ending horrifically...reading posts around this I’m concerned there’s a trend. My MOT was carried out in March with no advisories. Serviced in January. My garage are shocked and upset about this, as there was no sign of corrosion and they believe it’s corroded on the inside. How can this happen and be ok? Any idea if I’d be able to take this further with Mercedes?

Contact your local Mercedes dealer,explain what has happened,and ask them if you can claim on the corrosion warranty.they should book you in to do a report,which is sent to Stuttgart for a decision.

 

[Wighty]

Would there be any advantage in me spraying some Dinitrol rust converter into the rear subframe ? Especially as I have two 9 year old MB's