For a 2010 Mercedes S350 4MATIC front air suspension repair, the safest choices are a genuine Mercedes-Benz strut or the equivalent Bilstein unit (Bilstein supplies the factory AIRMATIC struts for the W221), with Arnott as the main lower-cost new alternative. Whatever brand you pick, it must be the 4MATIC version for the correct side: 4MATIC front struts are different from rear-wheel-drive ones.
Below: how to match part numbers, how the brands compare, failure symptoms, and whether to repair or convert to coils.
Quick Answer: Which Brand to Buy
| Option | What it is | Best for | Watch out for |
|---|---|---|---|
| Genuine Mercedes-Benz | Dealer part, factory spec | Owners keeping the car long term | Highest cost; confirm the part by VIN |
| Bilstein (B4 air strut range) | The supplier’s own-brand version of the OE strut | OE-level fit and damping for less than dealer price | Left and right are different part numbers (e.g. 44-110482 front left, 44-110499 front right, per parts listings) |
| Arnott | New aftermarket strut with a ContiTech air spring and its own tuned twin-tube shock | Budget-conscious repairs | Owner reports on quality are mixed; read the current warranty terms |
| Remanufactured / unbranded | Rebuilt or generic units | Short-term fixes only | Inconsistent quality and support; not recommended for a heavy, fast car |
What Fits a 2010 S350 4MATIC Front Air Suspension?
The 2010 S350 4MATIC is a W221-generation S-Class with AIRMATIC air suspension and adaptive damping (ADS). Each front strut combines the air spring, the electronically adjustable damper and the connectors in one assembly.
Part numbers are side-specific. Use them as a cross-check, not a guarantee, and always confirm with your VIN at a dealer or parts catalogue.
- Front left (4MATIC): OE numbers include A2213200438, A2213205313 and A2213201738 (Arnott AS-2853, Bilstein 44-110482 per their listings).
- Front right (4MATIC): OE numbers include A2213200538, A2213205213 and A2213209813 (Arnott AS-2852, Bilstein 44-110499 per their listings).
- Not interchangeable: rear-wheel-drive W221 front struts and ABC (Active Body Control) parts will not fit a 4MATIC AIRMATIC car.
The S350 4MATIC name was used in different markets with petrol and diesel (BlueTEC/CDI) engines, so check your exact model code before ordering.
Best Air Suspension Brands for the S350 4MATIC
1. Genuine Mercedes-Benz
The dealer part is the reference for fit, ride height and damping. It costs the most, but it removes any doubt about compatibility and usually comes with the dealer’s parts warranty.
2. Bilstein
Bilstein manufactures AIRMATIC struts for Mercedes, and its aftermarket W221 4MATIC struts are listed as the OE-equivalent unit. For most owners this is the best balance of factory-level quality and price.
3. Arnott
Arnott sells new (not remanufactured) W221 4MATIC front struts with a ContiTech air bladder, new bump stop and fittings, and a custom tuned shock, according to the company’s product announcement. Arnott advertises a limited lifetime warranty; check what it covers (labour is usually excluded).
Owner forums contain both good and bad experiences with aftermarket struts, so buy from a seller with a clear returns policy.
Arnott vs Bilstein Front Air Struts
| Factor | Bilstein | Arnott |
|---|---|---|
| Relation to factory part | OE supplier’s equivalent | Independent aftermarket design |
| Air spring | OE-type | ContiTech bladder |
| Damper | Bilstein ADS damper | Arnott-specified twin-tube shock |
| Price | Mid to high | Lower |
| Warranty | Check seller/manufacturer terms | Limited lifetime (advertised); check terms |
If budget allows, Bilstein is the safer pick. Arnott makes sense when cost matters most and you can live with a less factory-like feel.
How to Spot a Failing Front Strut
- The front corner sits low after the car has been parked overnight.
- The compressor runs more often or for longer; you may see an AIRMATIC warning.
- Hissing near the wheel arch, or bubbles when you spray soapy water on the air spring and fittings.
- Cracked, dry or worn rubber on the air bladder.
- Oily residue on the strut body or a bouncy, floaty ride, which points to a worn damper.
A sagging car can also have a leaking line, valve block or a weak compressor, so get it diagnosed before buying struts.
Repair the Air Suspension or Convert to Coils?
- Repair (recommended for most): keeps adaptive damping, self-levelling and the ride the car was designed for.
- Coil conversion: lower ongoing cost, but you lose levelling and adaptive damping, and the ride is usually firmer. Conversions also need the electronics handled properly to avoid warning lights.
Replacing both front struts together keeps the ride even side to side, and Arnott itself recommends replacing them in pairs.
Installation Tips and Costs
- Lift the car with the AIRMATIC system in jack mode (or disable levelling) before working on it.
- Release air pressure safely before disconnecting the air line; never loosen a pressurised fitting.
- Torque fasteners to Mercedes spec and get a wheel alignment afterwards.
- Have the ride height checked and, if needed, calibrated with a diagnostic tool.
Prices change often, so compare current prices from dealers and reputable parts stores, and factor in labour and alignment. Diagnostic tools can help with fault codes and calibration; see our guide to car maintenance and diagnostic devices.
Where to Buy
Buy from a Mercedes dealer, a reputable online parts retailer, or an air suspension specialist. Before you order, check:
- Side (left/right) and 4MATIC fitment match your VIN
- Whether there is a core charge for your old strut
- Warranty length and whether labour is covered
- Return policy if the part is wrong or faulty
Other Mercedes guides: C-Class saloon dash cam buying guide and best phone holders for the W213 E-Class.
FAQ
Are 4MATIC and rear-wheel-drive S-Class front air struts the same?
No. W221 4MATIC models use different front struts from rear-wheel-drive models. Order the 4MATIC version for the correct side and confirm with your VIN.
Who makes the original W221 air struts?
Bilstein supplies AIRMATIC struts for the W221, so a Bilstein-branded strut is the closest aftermarket match to the factory part.
Is Arnott or Bilstein better for an S350 4MATIC?
Bilstein is closer to the factory part and is the safer choice. Arnott costs less and comes with an advertised limited lifetime warranty, but owner experiences are mixed.
Should I replace both front struts at once?
It is recommended. Replacing them as a pair keeps ride height and damping even from side to side.
How do I know if my front air strut is leaking?
Look for a corner that sags after parking, listen for hissing, and spray soapy water on the air spring and fittings. Bubbles show the leak.
Is converting to coil springs a good idea?
It lowers future repair costs, but you lose self-levelling and adaptive damping, and ride comfort usually suffers. Most owners are better off repairing the air suspension.
