Changed the diff oil after 130,000 miles. The original oil was pretty dark.

 

Yup, ya did.

So... was it difficult? Any tips or tricks you found along the way?

How did you do it? Vac extractor or something??

 

No need for any of those, just gravity
Its the easiest DIY you can do, take the filler cap first just in case drain is stuck, then drain plug and drain it. My picky side dictated me to pour a few ounces of new fluid when the bottom was still out so it washes out all the "dirt and debris"...
Close the bottom, torque it and then fill until it starts to flowing out of the fill plug, close it and torque it again, thats it. Ahh sorry, also my picky side kicked in again so I jacked up the car just a couple inches from the side plug is facing that way I can get a couple of more ounces in lol.
I used some sort of tread lock&sealer on both plugs, I can`t remember the name now.

 

Yeah sorry, not a very detailed post 😂 just a simple drain and fill. I did use a hand operated oil pump that’s meant for quart bottles to fill it up. Just thought to post the photo because I’ve seen posts of people change their diff oil at 100,000 miles and the old fluid looked almost new. Mercedes doesn’t have an interval for the diff oil so I do think it’s important to change it based off how my fluid looks. Obviously I’m going off of looks and not doing an oil analysis, but it does look very dirty.