I remember changing it on my S430 4matic.
My mechanic advised me the oil doesn't need to be changed?
I don't understand I have 100,900 miles on my S550 4Matic.

 

The 550 has a drain plug and you can remove the cover on trans dipstick tube. They sell a dipstick for checking the fluid level. If you have an extractor and don't mind leaving the old filter in the pan, you can drain and fill from the tube. The tube cover can be put back on and a new plastic lock/clip installed. If you extract 4 quarts, just replace with 4 quarts...

The MB transmission Kit is about $60- Includes, New Drain plug, o-ring, new pan bolts, new filter and gasket. Pretty cheep....

 

Thank you for the comment. I also stand corrected on my particular model. They removed the Dipstick totally. The only dipstick on the 2014 S550 4Matic is for the Oil. Its now in the rear of the drivers side with a gray cap.

Trans needs some special attention to drain and fill properly.

 

2014 s550 4matic has a Gray Cap Oil Dip Stick on the Driver Side rear of engine bay. I have an Extractor that I used to do the oil change. I was only able to get 6 Quarts out. I was curious how much oil would remain in the pan after using the extractor. It left a lot behind. I finished the drain from the bottom.

Next oil change, I will attempt one more time with the extractor, I was sure the tube ( about the size of a fish tank air hose ) went all the way to the bottom. I will try a different hose next time and confirm.

This is the Extractor I use. Great product and price!
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1