Mercedes-Benz Change Differential Fluid
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The front differential takes SAE 75W-85 hypoid gear oil meeting MB 235.7, Mercedes part number 001 989 33 03 12. Mercedes often treats it as a lifetime fill, but changing it roughly every 60,000 miles is cheap insurance, and sooner if you tow or have started to hear a whine. The photographs here come from the differential fitted to the 2006 to 2011 R-Class, ML and GL.
At a Glance
- Symptoms of old fluid or wear: a whine, howl or hum from the front of the car, especially at steady speed.
- Oil: SAE 75W-85 hypoid gear oil meeting MB 235.7. Confirm the spec for your car by VIN.
- Always loosen the fill plug first, so you are not left with an empty differential you cannot refill.
- Fill until oil starts to drip from the fill hole, then refit the plug with a new washer.
- Check the drain plug magnet. Heavy glitter or chunks point to worn bearings.
Changing Mercedes’s front differential fluid is relatively easy, and most DIYers can complete this job in less than two hours.
What you will need
- Mercedes Differential Hypoid Gear Oil
- Mercedes part# 001 989 33 03 12, MBZ Approval: 235.7
- Hypoid Gear Oil (Differential Oil) SAE 75W-85 meeting MB 235.7 (sold in 1 liter bottles)
- Mercedes Hypoid Gear Oil SAE 75W-85 Differential Transfer Lubricant
- Note
- Always confirm the approved differential fluid for your car with a Mercedes-Benz dealer using your VIN.
- Transfer Pump
- 8mm Allen wrench
- Car Ramps
- Jack Stands
Procedure
- Drive your Mercedes-Benz up on car ramps, set the parking brake, and place wheel chocks behind the rear wheels to prevent the car from rolling back.
- Secure the vehicle with jack stands.
- Slide under the vehicle. Remove the front splash shield. It is held in place with several 8mm screws.
- Locate the drain and fill the plug. Note that some models only have a fill plug. The same plug is used to drain the oil. If your Mercedes differential only has one plug, use a transfer pump to suck the oil out of the front differential.
- Always remove the fill plug first to ensure you can remove it. You don’t want to drain the fluid and realize you can’t remove the fill plug.
- Next, remove the drain plug and allow the oil to drain. Look at the old oil and the drain plug magnet. A fine gray sheen is normal wear, but heavy metallic glitter or chunks point to worn bearings or gears.
- Once all fluid has drained from your Mercedes-Benz’s front differential, it is time to reinstall the drain plug. If a new drain plug is available, replace it or the washer.
- Add Mercedes differential fluid until the differential is full and you see fluid starting to drip from the fill hole.
- Reinstall the fill-hole plug. Reinstall the filler plug with a new sealing washer and tighten it to the torque in your service manual.
- Lower your Mercedes-Benz and take it for a spin.
The pictures in this guide are taken from a differential fitted on 2006 to 2011 R Class W251, ML-Class W164, and GL Class vehicles. While the front differential is slightly different in E, C, and S-Class models, these instructions can be used as a general guide for all Mercedes-Benz owners with 4Matic.
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Safety
- The car must be level to fill correctly; raise both sides evenly and support it on jack stands.
- Gear oil can be hot after a drive; let it cool before opening the drain plug.
- Dispose of used gear oil at a recycling center or auto parts store.
Frequently Asked Questions
How often should I change the front differential fluid on a Mercedes 4Matic?
Mercedes often treats it as long life fluid, but changing it every 60,000 miles or so is cheap insurance, and sooner if you hear a whine or tow regularly.
The whine did not go away after the fluid change. What now?
New fluid can quiet a mild whine, but a howl that changes with speed usually means worn bearings or gears. See our front differential removal guide for the repair.
How much fluid does the front differential take?
It varies by model and is usually around one liter. Fill until it starts to drip from the fill hole rather than relying on a number.
Check these troubleshooting and repair guides for more help on your Mercedes-Benz vehicle.
