MOT failure due to a damaged coil spring on the Mercedes W211.

[DreamWeaver]

Greetings to everyone,
My vehicle is a 2009 Mercedes W211 E280.

Yesterday, the MOT failed due to a broken offside rear coil spring. I did not see any difference in driving with the damaged coil spring; is this typical?

I contacted my local Mercedes-Benz dealership about both rear coil springs, and they quoted me £207 for the springs and seals. However, they do not have them in stock, and if I place an order, I will need to wait 5 to 7 days.

My MOT expires on Friday; I have learnt to schedule a MOT 3 to 4 weeks in advance of its expiration.

My alternative is to purchase coil springs from GSF Parts, who charged me £98 for each. The brand is Lesjofors, and I believe they do not include seals.

Should I purchase them or order them from the Mercedes-Benz dealer and await their arrival?

Any guidance would be much appreciated.

Thank you.
 

[bvlenci]

The visibility of the break in the spring may vary depending on its location.

Mercedes coil springs are tailored to the car and its array of optional features. The springs are accompanied with a code of coloured dots. I would like to await the appropriate components.

[Matt865]

Visit the Sachs website; they will likely direct you to the appropriate springs.
Given the quantity, eBay vendors can likely deliver them to you within a few days.

What are the seals to which you refer?

[ianwh4]

They almost always fail due to the last turn of the coil fracturing, which has little impact on ride height and is thus easily overlooked. I failed to see them on my wife's 70,000-mile A Class during my pre-MOT inspection, despite being a former tester. In the instance of the A Class and my previous ALFA, the issue stemmed from inadequate spring design; the lower end of the spring was cut square, resulting in a sharp edge that contacted the underside of the subsequent coil during compression. This eroded the paint and began to affect the coil itself, allowing rust to infiltrate until they fractured. If the ends were bevelled, it likely would not occur. The positive aspect was that, being a 2006 vehicle, I acquired a new set of original factory components for just £40, and apart from the removal of the rear wheel, no bolts required adjustment for their replacement, use only my existing spring compressors.

[Craigbelont]

I failed to detect a fractured front spring on my W204 during a pre-MOT examination due to its breakage occurring close to the end.

Both Mercedes-Benz vehicles I have had experienced a fracture of one front spring, and in each instance, I replaced just the fractured spring. In both instances, the right colour-coded replacement spring did not result in an uneven ride height, and in neither case did the other spring fail after many further years of service.

[Chrishazle]

Similarly, the front spring on my wife's W246 fractured; I replaced it alone with one purchased from eBay. After 35,000 miles, the opposite side remains intact, exhibiting no variation in ride height, braking, or handling. We do not using it on track days; nonetheless, it seems suitable for regular usage.

[AMG33D]

I had many damaged springs, both front and back. Installed Eibach components without any issues to yet.

[carBlacken]

I would only install springs or shocks in pairs.

[Paulinelinker]

The primary distinction between authentic springs and quality aftermarket options (which I would only install from Bilstein) is that the Mercedes-Benz springs are specifically tagged to the vehicle based on its specifications, hence they can only be bought using the chassis number. Authentic springs are distinguished by various coloured paint marks that should correspond with the original markings on your vehicle. These markings indicate minor weight variations based on your vehicle's specifications, as well as different suspension configurations such as standard, Sportline, etc.

Aftermarket springs may lack precise coding for specific vehicles; however, purchasing OEM components, such as Bilstein, and verifying your chassis number against the manufacturer's website should yield a part of comparable quality to the original. In such instances, I recommend replacing components in pairs due to potential minor specification discrepancies.

Alongside the springs, it is advisable to change the rubber shims, which are specifically coded to the vehicle and vary in thickness, identifiable by the number of 'bumps'—ranging from one on the thinnest to four on the thickest.

In an optimal scenario, components like springs and shocks ought to be replaced in pairs (similar to tires) across an axle. However, akin to a punctured tire, it is permissible to replace a solitary broken spring, provided that the corresponding spring on the opposite side is inspected and confirmed to be in satisfactory condition.

During the examination of springs, assess the condition of the surface paint finish: if it has deteriorated, exposing any portion of the spring's bare metal, which is prone to rust in our humid climate and particularly after exposure to road salts, the resulting corrosion can render the spring highly vulnerable to failure.

Springs are susceptible to failure under very cold temperatures, as shown in recent conditions.

As previously mentioned, failure at either extremity of a spring may be difficult to detect, and a fractured spring does not always result in a noticeable change in driving dynamics.

I consistently examine my springs whenever the wheels are removed, whether for tire replacement or for the inspection or replacement of braking components. It is also advisable to inspect suspension components, including ball joints and drop links for anti-roll bars, whenever the wheels are removed.