Lubricants guideline required

[moonraider]

AoA brothers
I am new to 4x4 fraternity. I have a few questions and request guidance.
Jeep: prado 03, 1kd d4d, 166k on odo
Which engine oil/oil filter to use? Previous owner used
Total 20w 50
Which transmission differential oil/viscosity/duration?
Any other guideline for new 4x4er?

Thanks in advance