Hi all, changed the oil on the transfer box today, here's how in case your interested..
Goto Vauxhall and get transmission oil, Vauxhall part no 9196535, this stuff is specially formulated for the Antara, apparently, about 30 quid for a litre, my Vauxhall agent gave me a discount, paid about 25 quid.
Take the car for a drive to warm the oil.
Jack up the front as high as you can get it.
Remove bottom engine cover.
Get yourself about 5 ft of hose pipe.
10mm Allen key to undo the drain and refill plug
Check you can undo the refill before draining,mine was worrying easy to undo!
The drain plug appears to have a magnet in it, check this for bits of stray metal, mine was ok.
Drain the old oil out.
Read somewhere that you refill through the breather hose, mine dont appear to have one so...
Feed the hose from the engine bay down to the refill hole, and shove it in, fit a funnel to the hose.
While holding the hose in place get the missus to tip the new oil into the funnel and get her to keep doing this until oil runs out of the refill hole, this is also the level plug.
Check both plugs are put back nice and tight but don't over do it, would probably mean a new transfer box if you strip the thread.
Mine took most of the 1 litre can.
Didn't have a manual, was crapping my undies as never done this before but if I'm honest it was easy.
2012 2.2 Diesel automatic SE Nav 184bhp