W163 ML270 cdi 2003 114K miles
I have been reading online all your views regarding ‘sealed for life’ automatic gear box and what this really means i.e. safe to just get past warranty period! This got me thinking is this the same for the rest of the transmission and should I look to change the front and rear differential oil say every 50K miles and maybe the transfer case as well. I assume this is just a case of draining the oil via the drain plug and filling back up with fresh oil till it starts to run out of the fill plug. If this is the case what oil (synthetic?) would you recommend (75W85 or 75W90 or 80W90 any thoughts?) and how much would I need for each diff? Is this worth doing? I also presume the transfer case take normal std automatic transmission fluid - is that correct? I assume with the ml I would have enough clearance to get access without the need to jack the car up on ramps. I have checked in the owners manual and none of this info is listed so would appreciate it if anyone can confirm what the oil grade should be, the MB spec and how much I will need.

Thanks in advance

tony