Leveled the vehicle with a water spirit level at the running board and drained the rear differential fluid after 30min of cool down. Pumped in one quart of Red Line 75W90 fluid; probably spilled a little using a 500cc syringe yet none of the fluid overflowed from the fill port.

Diff case marking was A213 351 00 08



Had to get another bottle the next day and fill approximately 130ml to get the diff oil starts overflowing.

YouTube videos I watched had the diff oil overflowing within the 1 quart of fluid. Anyone had similar experiences not overflowing with 1 quart of fluid?

Personally I wouldn’t put just any old gear oil in there. MB upgraded the diff oil for our cars with what they call special oil. There words not mine. Our GLC43 had a slight noise from the diff when slowing down at stop lights or similar. I replaced the oil with what they gave me. It was only 1 litre and it filled it from memory. Stopped the noise immediately, and they also gave it to me for my ML63. It’s extremely expensive but cheaper than a new differential. Pretty sure it’s a full synthetic gear oil. About $130 a litre from memory.

The current oil drained out was last serviced with Mercedes fluid ~15k mileage. Cost for MB239.71 was SGD$38 or ~ USD29 per litre.

It was clear but had lots of sparkling bits. Not gonna use this oil back in the diff.



Previously the rear had a soft whine when letting go pedal at ~90kph. The Red Line oil was thicker than MB oil and not sure if it was the thicker oil or fresh oil that cures the soft whine now.

It's strange to me that all those who serviced their rear diff used 1 quart (946ml) and was enough for the fill.

They maybe didn’t drain it as well as you did.
Is the redline oil MB approved for your diff?
Ill see if I can find the invoice for the oil I got.

It was more expensive than I remember. It is 239.71/2 so maybe that /2 adds $150 to it. 🤣
In any case the noise has been gone for over 12 months.

This was for the ML63 but the same stuff as the 43