Front spring broke

[Kyiv]

I was driving today and suddenly heard a sound, like when a rock hits windshield on a highway. Only the sound came, as if from behind HVAC panel. Car continued to drive normally, nothing on the windshield. At the next stop I inspected front of the car but did not see any damage from a foreign object. Drove another 12 miles home - at freeway speeds - and while measuring front passenger rotor run-out saw this...



Both front and both rear springs were replaced 5 years/20k mi ago with Mercedes branded units that I've purchased and delivered to my at the time Indy myself. Just recently I've checked via ISPPI vs my 5 year old FCPEURO order that front spring were correct for my car. However, I don't see part # printed on either of the front springs, but there are color marks: two yellow, two green, one blue on both. Should there be part numbers printed/stamped if the springs are MB branded?

EDIT: my other question is - how is this even phaking possible?

 

[kwontumspeed]

Wow, that could've gone very wrong, very quick. Glad you are home safe!

 

[JC220]

Yep this happens! If MB genuine springs yes they will have at least an embossed part number on the spring end. You would have to remove the spring in order to check for this number. MB do also print the part number visible on the spring in some, but not all cases. The different paint colours you describe would suggest to me they are genuine springs because MB group and grade the springs with the colour coded system. Whereas aftermarket springs wouldn't typically have this colour code system on them.

In any case it is good practice to replace a pair of springs on an axle - not just one. So you should be ordering a new pair of front springs and change both now.

 

[Kyiv]

Yep this happens!

Now I know, lol. I thought only old, rusted springs can brake and not a 20k mi original Mercedes part with zero rust. The chance of it is probably equal to matching 6 digits in a lottery. I'm still in a disbelief..

 

[Seangbadee]

I was driving today and suddenly heard a sound, like when a rock hits windshield on a highway. Only the sound came, as if from behind HVAC panel. Car continued to drive normally, nothing on the windshield. At the next stop I inspected front of the car but did not see any damage from a foreign object. Drove another 12 miles home - at freeway speeds - and while measuring front passenger rotor run-out saw this...

View attachment 99875

Both front and both rear springs were replaced 5 years/20k mi ago with Mercedes branded units that I've purchased and delivered to my at the time Indy myself. Just recently I've checked via ISPPI vs my 5 year old FCPEURO order that front spring were correct for my car. However, I don't see part # printed on either of the front springs, but there are color marks: two yellow, two green, one blue on both. Should there be part numbers printed/stamped if the springs are MB branded?

EDIT: my other question is - how is this even phaking possible?

Glad you're safe

 

[gsxr]

Now I know, lol. I thought only old, rusted springs can brake and not a 20k mi original Mercedes part with zero rust. The chance of it is probably equal to matching 6 digits in a lottery. I'm still in a disbelief..

You are right. This is typical on old, rusty springs. I've never heard a report of relatively fresh springs snapping like this. Wild guessing, perhaps the spring was not seated well in the LCA pocket, and over time stress killed it? @Klink?

Photo below of where the MB part number appears at the end of the coil. Some times you have to scrape off the paint to see the numbers, some times it's visible through the paint as in this picture.

 

[northNH]

Perhaps of interest, still available...


“These MB OEM E420/400E front shocks (124 320 6330) and springs (124 321 3904) were newly installed ~5K miles ago, providing that wonderfully silky ride that grandparents love.
2 weeks ago they were removed and replaced with stiffer lower Sportline parts.

With most all their life still ahead of them, well worth installing if you’re satisfied with the creamy ride they provide.
Scant scattered superficial rust, functionally as new.
$325 with shipping USA.”

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[speedy300dturbo]

Apparently MB knew about the tendency for corrosion to occur where the coil spring meets the LCA. Models designated for Scandinavian countries came with a zinc sleeve fitted to the bottom of the coil spring where it sits in the LCA pocket.

 

[sheward]

Seems to me the spring may have been defective.

drew

 

[northNH]

Two things...

I’ve owned well over a dozen German cars from the 60’s thru the 90’s; MBs, Porsches, BMWs and Audis. During that period I’ve replaced 6-8 various broken coil springs, some rusty, some not. Improper lower pocket seating definitely not the issue...
Over the same lifetime I’ve also owned dozens of Swedish cars (Volvos, not the other ones) and I’ve never once had to replace a broken spring.

And most recently one of my now-60K mile non-rusty coupe Sportline springs broke just like yours, like a rifle shot.
And it had one of those zinc sleeves on the bottom...

 

[Kyiv]

Perhaps of interest, still available...


“These MB OEM E420/400E front shocks (124 320 6330) and springs (124 321 3904) were newly installed ~5K miles ago, providing that wonderfully silky ride that grandparents love.
2 weeks ago they were removed and replaced with stiffer lower Sportline parts.

With most all their life still ahead of them, well worth installing if you’re satisfied with the creamy ride they provide.
Scant scattered superficial rust, functionally as new.
$325 with shipping USA.”

Attachments

• View attachment 99887
  
  5FA5C6C1-9E37-40BF-BCE5-9733BD3FFF7E.jpeg
  
  4.4 MBViews: 11
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  D92FFF2F-6B4D-4CFD-80F0-AE135F1E84A1.jpeg
  
  2.5 MBViews: 8

Very tempting! Not too long ago, I've learned that my current front struts, Sachs 115-070 are not correct for my 400E, I've been contemplating replacing them with a correct part "sometime". This might be a "perfect" occasion. I'll see if FCPeuros "lifetime replacement" works out or not first. Never tried it. Prudent thing would be to get free springs, if there is an option... Thanks

I see in the picture that your springs have different color coding... So using different appropriate shims for each is the same as using two springs with the same color code and same size shim?

Lastly, how much less "creamy" the ride is with a sportline suspension? Just general curiosity

 

[Kyiv]

Two things...

I’ve owned well over a dozen German cars from the 60’s thru the 90’s; MBs, Porsches, BMWs and Audis. During that period I’ve replaced 6-8 various broken coil springs, some rusty, some not. Improper lower pocket seating definitely not the issue...
Over the same lifetime I’ve also owned dozens of Swedish cars (Volvos, not the other ones) and I’ve never once had to replace a broken spring.

And most recently one of my now-60K mile non-rusty coupe Sportline springs broke just like yours, like a rifle shot.
And it had one of those zinc sleeves on the bottom...

With your experience, could you make a speculation as to why? Until today, I believed that a spring is a most durable suspension part, with strength headroom to spare, that never fails, unless rust + really old age...

 

[195910]

That is rather concerning. I am noticing some quality issues in original M-B parts, my latest experience was the ignition wires set bought last year (paid nearly 3 time more than a Beru set). More on the Brabus hiccup thread.

 

[northNH]

I see in the picture that your springs have different color coding... So using different appropriate shims for each is the same as using two springs with the same color code and same size shim?

All but the Red and Blue stripes are production notations and are apparently of no significance regarding spring characteristics.
Blue (longer) or Red (shorter) represent production performance variables and determine the pad thickness to equalize those characteristics within a pair of same part # springs:
e.g. Blue + 8mm = Red + 13mm; Blue + 13mm = Red + 18mm...
My Blue 400 springs shown for sale were correctly paired (as per EPC) with thinnest 8mm pads when removed from the vehicle.

Seems to me the spring may have been defective.

Whilst not macroscopically (i.e. cracks), I agree microscopically (i.e. casting voids).

Lastly, how much less "creamy" the ride is with a sportline suspension? Just general curiosity

Still creamy, less foamy...

 

[gsxr]

northNH is correct. Only the single red or blue stripe means anything, and it only indicates a length variation, to be compensated with spring pads. The "correct" pad thickness is specified in the EPC charts. This cannot be found in the FSM.

http://www.w124performance.com/images/W124_suspension/spring_paint_stripes.pdf

 

[northNH]

Damn well should be correct, I learned it all from you.

 

[Kyiv]

Still creamy, less foamy...

So, basically, sportline suspension eliminated constant micro/mini bobbing of the standard suspension, but did not add [much] impact harshness?

 

[northNH]

No, I’d say Sportline setup better transmitted/communicated the smaller imperfections in the road surface and pitch, feels less filtered, only slightly stiffer. Wouldn’t be fair to call it “harshness”, certainly not compared to most aftermarket e.g Bilstein Sports/H&R, AFAIK.

I wouldn’t say “micro/mini bobbing” was or is or should be a characteristic of either set of shocks/springs, standard E400E MB or Sportline.
Non-E400E shocks? Hmm...

For “bobbing and weaving” however, Sportline immediately better...

 

[JC220]

Springs can break for a variety of reasons. But failing or in your case perhaps incorrect shocks could have done the trick! Add a pair of correct dampers to the list

 

[Kyiv]

Springs can break for a variety of reasons. But failing or in your case perhaps incorrect shocks could have done the trick! Add a pair of correct dampers to the list

The Sachs 115-070 that are on my car right now, as I understand, are meant for 300E Sportline. All online catalogs list them as for 400E. I know better now. Don't know if they could be the culprit

 

[Kyiv]

I wouldn’t say “micro/mini bobbing” was or is or should be a characteristic of either set of shocks/springs, standard E400E MB or Sportline.
Non-E400E shocks? Hmm...

I've got a semi-Frankenstein suspension set up on my car due to lack of knowledge and relying on online catalogs at the time of suspension renewal 5 years ago, when I acquired the car. Front springs are correct, but struts are Sachs for 300E Sportline (stiffer). Rear springs are from a 300E (softer), but shocks are correct-for-400E Bilstein (OE version). So the front is overall stiffer then it should be and rear is overall softer.. I've only learned this very recently. Already ordered correct rear springs and based on how it goes with FCPeuro's "lifetime replacement" for front springs on Monday - might buy both of your sets

 

[Jlaa]

... So the front is overall stiffer then it should be and rear is overall softer..

So understeer city! ;-)

 

[gsxr]

The Sachs 115-070 that are on my car right now, as I understand, are meant for 300E Sportline. All online catalogs list them as for 400E. I know better now. Don't know if they could be the culprit

I don't know the aftermarket stuff very well, but my notes indicate the 115-070 are an "HD" version, while the 115-069 are "comfort".

Of interest here is that both Sachs and Bilstein basically offer 2 different struts for the majority of 124 applications, and Bilstein also offers a Sport. But Mercedes has probably dozens of different part numbers, each with different specs. Aftermarket stuff is trying to be one-size-fits-all (ok, two sizes) similar to lowering springs (again, MB has many springs, most aftermarket offer only a few sets). Of course the downside to the OE dampers is they only have a 1-2 year warranty, vs lifetime on the aftermarket...

 

[Cobra]

Hi

My front springs broke at about 140 000 kilometers so i replaced both the springs and the dampers in front, with
original Mercedes Benz items of course, even the E500 specific dampers.

The Swedish MOT personell aborts a MOT if the springs are broken due to the risk of accident in the process of lifting the car.

I have owned a number of Swedish cars and in the 70:is and in the 80:is there was a number of springbrakes, but after the 90:is
the frequence decreased, probably to the change of method in rustprofing the cars.

BR
Totte

 

[Kyiv]

@northNH, I sent you a PM