So I've been a little worried about my front diff (65k miles) because like many e63's and e350 4 matics, it seeps/oozes oil from one or more of the shaft seals. The shafts are at the fill line but I worried about the gears throwing oil around inside the case above the fill line and a portion of it leaking out over time. I used the "pump it in through the drain plug method" to refill and the whole job took maybe 1/2 hour. The diff had been leaking long before I bought the car at 48K miles and I'm happy to report I still had over 525ml oil in the diff (full fill is 550 ml). The old oil was pretty clean color wise (original fill) but there was some super fine sparkle in the oil. Being that it was never changed after break in I understand that that is pretty normal so I'm not going to worry about it....

 

Good to know - I have same seepage

 

Thanks for sharing your findings.

 

Glad it worked out. That's why I kept saying it's a no brainer. We spent more time debating the change interval than it actually took for you to change the fluid.

 

That is actually super true.

As they always say, better safe than sorry and preventative maintenance is always a good thing.