Bribenz,
If you wait till your transmission oil is burnt or overheated, then the trainny is done.

If the transmission is sealed for life as you meant to believe. Then, how long or how do you define Life.
Is it:
50K (warranty/car lease life)?
100K ( I hope not)?
1Million ( now you're talking)?
The problem is no one know the definition of the MB transmission life.
If I remember right: 25 degrees F temperature increase reduces cooling and lubrication by half!

I have decided, rightly or wrongly, that my transmission oil change life is 100K,
Please for all you gurus(Gilly, Ray...etc) tell me am wrong.

Am still waiting for someone to tell me the correct MB way if you have to change the oil.