Outer Limits 4x4 Board

hi guys im in need to know what oil to use for the gear box and diffs for a 75 series as the old man hasnt changed the oil in 170,000kms (he claims),
what damage will he expect?

http://www.motorco.com.au/upimages/hzj7 ... atalog.pdf

I would expect to see lots of messy crap in there water and oil if he's done any water crossing etc, i'd be inclined to do wheel bearings and even pull centre's if it's really messy.