Comment identifier un différentiel arrière Mercedes par numéro OEM (ZF HAG170, A2483502600)

Ordering a used rear differential for your Mercedes is not a guessing game. Get the OEM number wrong and you end up with a unit that physically fits but has the wrong gear ratio, wrong output flange, or wrong locking spec — all expensive mistakes. Here is how to do it properly.

Why the OEM Number Is the Only Number That Matters

Mercedes-Benz rear differentials look similar across many model years and body styles. A differential from a C-Class, E-Class, and GLE can share the same housing shape but have completely different internals. The OEM part number is the only reliable way to confirm you are getting a compatible unit.

There are two types of numbers you will encounter:

• Supplier/manufacturer code — for example, ZF (ZahnradFabrik) stamps their own designation on the unit, such as HAG170. This refers to the differential family or series built by ZF for Mercedes.
• Mercedes-Benz part number — for example, A2483502600. This is the number Mercedes assigns in their own parts catalogue and is the most precise identifier for a specific application.

When searching for a used part, always lead with the Mercedes part number. Use the supplier code as a secondary cross-reference.

Where to Find the Part Number on the Vehicle

Before you go online, locate the number on your own car. This protects you from catalogue errors and VIN decoder mistakes.

1. Differential housing stamp On most Mercedes rear axles, a metal tag is riveted or stamped directly onto the differential housing or the axle carrier. It typically shows the ZF production code and sometimes the Mercedes part number. Check around the rear cover and the upper mounting points.

2. Sticker on the diff cover or housing Some units have a production sticker showing the gear ratio, build date, and part reference. This sticker is fragile — clean the area gently before reading it.

3. VIN-based parts lookup Use your 17-digit VIN on the Mercedes-Benz parts catalogue (ETK/WIS) or a trusted third-party lookup tool. This will tell you the OEM number for the exact differential that was fitted to your car from the factory.

4. Ask your dealer for the part number only You do not need to buy from a dealer. But asking them to look up the part number against your VIN is a legitimate and free way to get the correct reference before shopping elsewhere.

Decoding the Numbers: What They Tell You

Taking A2483502600 as an example:

• The A prefix indicates it is a genuine Mercedes-Benz part number (sometimes written without the A in catalogues).
• The digit block encodes the model series, axle type, gear ratio group, and specification variant.
• Even a single digit difference — say, A2483502700 versus A2483502600 — can mean a different gear ratio or a different locking differential variant.

For the ZF HAG170:

• HAG stands for Hinterachsgetriebe (German for rear axle differential).
• 170 is the ZF series designation indicating the torque capacity class.
• Within the HAG170 family there are multiple variants, so the ZF code alone is not enough to confirm compatibility — always cross it with the Mercedes number.

How to Match a Used Differential Safely

When buying from a used parts supplier like AutoParts EU, follow this checklist:

• Provide your full OEM number (e.g. A2483502600) when enquiring — not just the model and year.
• Ask for the number stamped or tagged on the actual unit in stock, not just what the listing says.
• Confirm the gear ratio — common Mercedes ratios include 3.07, 3.27, 3.46, and others. A mismatch affects your speedometer, fuel consumption, and drivetrain stress.
• Check whether your car has a limited-slip or locking differential — standard open diffs carry a different part number and are not a substitute.
• Ask about the source vehicle mileage and whether the differential shows any signs of oil leaks or bearing noise.

Tips for Mechanics Ordering on Behalf of a Customer

• Pull the number from the car physically, not just from the job card — previous owners may have swapped the diff.
• If the stamp is unreadable, cross-reference via the axle ratio plate usually found on the door jamb or in the service booklet.
• Always match output flange diameter and bolt pattern if you are reusing the customer's driveshaft and half-shafts.

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FAQ

Can I use a differential with the same ZF code but a different Mercedes number? Not reliably. The ZF series code covers a range of variants. Only matching Mercedes OEM numbers guarantees the correct gear ratio and specification.

What if the stamp on the used unit is damaged or missing? Do not accept the listing purely on the seller's word. Ask for a photo of the housing tag or stamp. A reputable supplier will provide this.

Does the differential from a petrol model fit a diesel model of the same generation? Sometimes, but not always — diesel engines often produce more torque, which can mean a different diff rating. Always verify via OEM number, not just engine type.

AutoParts EU ships from Bulgaria — how long does delivery take? Most orders to EU countries arrive within 3–7 business days. Contact us directly for a shipping estimate to your country before ordering large drivetrain components.