hi just wondering if u can replace n drain the differential oil i had a look and neva saw any plugs to unscrew to drain it. so my question is can u actually drain the diff fluid without pulling it apart. cos i know the 4wd's u can.
with the vn diff u have to undo the bolts and carfully pri the cover off and let the oil drain.. its a pain as u have to replace the gasket aswell. but im not to sure but u might be able to get a replacement cover with a drain hole (with enough money u can do anything)
to fill there should be a rubber plug on the middle of the cover (pri with flat srewdriver carfully)... i suppose you could pump some of the oil out of this hole but it is better to take the cover of so you can get all of the oil out and give the inside of the diff a good wipe
when i filled mine i got a pice of garden hose with a funnel attached and put one end in the diff and filled untill the oil was just comming out the hole
when i did mine i dident notice any difference in take off just a bit less noisy....(but then again im no expert) the oil to use depends on what typ of diff u have (normal or lsd) if you have a normal diff its, (Going by the gregorys manual) "gear oil 80W90 GLS" . but im not too sure what the lsd oil is. hope this helps