mis3

2 weeks ago I was driving out of my garage and all of a sudden, I heard a metal-snapping noise coming from the front. I went outside the car and could not find anything wrong. The car seemed OK so I went on to drive.

Today I dropped by an indie and he checked. Both front springs were broken! Strange that they both broke at the same place, a few inches from the lower end. He said since the springs still sit in the small cups, the car is not unsafe to drive. In essence, both springs are now 10-inches shorter.

The left spring was replaced 3 years ago while the right spring is original (14 years old). Are there any reasons that they both snapped at the same place?

I see that the parts are about $65-70US each. How much labour is it to replace each side?

JakeMS3

That's odd, curious to see what caused this.

mis3

To be specific, I am not sure if they broke at the same time. I know I heard a snapping sound 2 weeks ago, not sure if it was the sound of one spring or two springs.

tw2

I have seen a few posts on this now. Quite unusual but the other people seemed to experience breaking in the lowest coil too. There must be an excessive stress there. They were c-class but w203 and w209 are pretty much the same in this respect.

Replacement is easy for a shop, they just need a spring compressor and the tool for the nut on the top. I could do it in an hour taking my time if I had a proper wall mounted spring compressor.

Rudeney

MBZ's nice combination of sporty handling and comfortable ride is created by using springs made with different compression capabilities along the path of the coil. They do this by using different metal compounds within the spring. My guess is that one of those compounds near the bottom spiral is more susceptible to corrosion and will thus rust and break. It's probably worse in areas where road salts are used for clearing snow and ice.

mis3

My indie said the car is safe to drive.

Since both springs broke at the same location, can I just leave them? Any risk in driving this way?

I am concerned that since there is now less "turn" left inside the bottom cup which holds the spring, the spring can come out.

sailorben

Well they're broken, so I would change them. Regardless if they're 'safe' or not, they are not right. To DIY as said you need to manufacture a tool for the top nut, and also a spring compressor with cups on either end, to get the compression needed.

mis3

Too bad I am not a DIY person.
How much is the labour (in term of hours) to replace both springs?

mis3

The front springs were replace yesterday. I would let them settle for 1-2 weeks before alignment.

Do springs deteriorate over time? I am concerned about the rear springs. These rear springs are the original springs which means that they are 13 years old and I have been driven on them for over 230K miles.

tw2

I have not heard of the rear springs breaking. I think they are linear springs as well so there shouldn't be any blend of metals in there.

mis3

More specifically, does the performance of the rear springs deteriorate over time? In other words, if they do not break, there is no need to replace?

tw2

Shocks yes, springs I don't think so.

mrbobby

My CLK 500 broke both rear springs. The breaks was almost impossible to see as both were broken less than 6 inches from the beginning of the spring. As to driving with broken springs, call me a chicken, but, it's not something I would do.

Rudeney

Rear springs can break, too. And any spring, over time, becomes more compressed and will need replacement. There used to be a local shop here that did spring repairs. I think they would heat-treat them and stretch them back out, but that practice has all but died as it's about the same price to just replace with new.

tw2

I stand corrected. Thinking back I have definitely had sagging springs in the rear of my first few rubbish cars.

ItalianJoe1

BMW has this happen on the Z3/4 all the time, other models have it but less common. I've replaced many pairs for the exact same issue.

It's basically, once the covering paint fails, the rust weakens the spring, and that's the point where it takes the most stress and breaks. The other side was probably broken for a long time, there's no way both sides broke at the same time when you heard the noise.

Some springs have a rubber coating over them that holds up better to age. The Germans don't seem to believe in that.

I'm also in south FL where rust is normally not an issue. I imagine this happens more often in snow climates.

mis3

This is tricky. I will check hoth rear springs from top to bottom when I do the alignment.

ALFAitalia

I don't think you would miss it if the spring did break...aside from the reduction in ride height. The more of the spring that breaks off the harder the ride will be....until you hop around like a ricers Honda with cut springs!!

Rudeney

Or a car with ABC that has blown a hose. It happened on my SL and the thing was almost sitting fender-to-wheel. In fact, if the front wheels had been turned, they would have impacted the fender lips. ABC is a great system as long as it's working. But to me, it's worth the fuss.

A few weeks ago, I saw a W220 S-Class going down the road with the front bumper almost dragging the pavement, and the rear end a a foot higher in the air. It looked like a jacked-up dragster, but without the larger rear wheels. I don't know if it was some sort of weird ABC malfunction that caused it, or if it was on purpose (there are kits you can buy to fool ABC into different ride heights). After seeing the young driver and the rims on it, I suspect maybe the latter.

mis3

This is it. Both the front springs were broken and the ride did not suffer at all. Maybe it is because they both broke at the bottom end of the springs.

I checked my records and the rear springs are stock. So, they are 13 years old with 230k miles. This is why I asked the question if springs deteriorate over time.

tw2

Already? It feels like you only got the car a few months ago. At least the PS fluids will be fresh. I guess I will be in for similar fun with my new airmatic'd purchase.
I took mine out for coilovers last year. They were perfect, no rust, same age as yours but half the mileage.

Rudeney

I bought the SL last June, so almost a year, but that hose blew within the first few months. It was the main pressure hose coming out of the pump headed down to the front connecting block. It was easy to replace, but made a big mess. And Pentosin stinks like burned diesel fluid.

I was lucky in that I was literally in the parking lot of a shopping center with an Auto Zone when it happened, and they had two quarts of Pentosin on the shelf. I filled it up and made it home to swap cars until I got the hose delivered. BTW, the fluid in ABS and PS is the same type, and there is pump for both, but they are otherwise separate circuits. The duo-pump has two chambers, so changing ABC fluid has no impact on the PS system and vice-versa.

mis3

Not sure if visual inspection of the springs can check if they are sagging or not.
I read that over time, the springs weaken and would begin to loose height. Not sure if my alignment guy would measure the height.

M-Rods

I replaced both of mine one was broken on the lowest coil. It's an easy DIY though i just used a jack to slowly release the tension until the spring was loose, I found Bilstein replacements for $65 a side.

mis3

How are these Bilstein springs differ than the stock springs?

The price of these Bilstein is even lower than stock. From my CLK320, part,number of stock rear springs is 2103243604 and it's $82US. ,