Whats this?

If the hub seal is failed shouldnt grease coming out not oil?

Could it be the oil come from the diff?

From memory in a D2 the CV joints are in the open air (have a look yourself) so it would have to be a cool magic trick for the oil to jump from the diff to the wheel hub as the drive shafts aren't hollow. I'm pretty sure what you're seeing is "lubricant, wheel hub" which may be somewhere in between grease and engine oil in runniness.

I should start looking wheel hub replacement then. Is it ok to drive short distance apprx 10km with leaking wheel hub?

Can I reuse the wheel hub nut? Or I should get a new one

Dont you think its the O ring as on the picture?

Provided you have lubrication, driving it isn't an issue.

Is it the front or rear? If the front and you have a sealed swivel hub (meaning no drain plug, just a filler plug and filled with one shot) then open the filler (on top of the swivel, half inch drive socket) and check the level of one shot. If you have a drain plug, then you will also have a level plug halfway. Open it and check the level.

For the rear, open the diff filler on the housing on flat ground, if it is full it will dribble out, if not then it needs a top up. If it smells burnt, then you need to drain and refill cause your oil is shot and no longer lubricating.

Oil is there as a lubricant and to make sure it doesnt wear put. No oil means damage. The seal is just there to keep the oil in. You can drive on a blown seal for the amount of time you have sufficient oil in there, plus the amount you want to spend on said oil before fixing said seal.

Sent from my SM-G900I using AULRO mobile app

So I tightened the hub nut, filled diff as no oil dripping when filler open. Drove 5km or so and no sign of oil on the wheel.

Hopefully the seal is still fine and by tightening the hub nut pull the O ring and make a good seal. Finger cross is ok now because we are going away for long weekend grand final.

In saying that I ordered hub nut and the O ring and will arrive tommorow in case it start to leak again.

If you had to put a lot of oil in it, I would drive it around a bit and then check the oil - make sure its still a nice colour and doesn't look burnt or smell all sorts of awful. Once it gets to that point drain and refill but hopefully it was just a loose nut.

Sent from my SM-G900I using AULRO mobile app

That nut should be done up to a torque value of 360 ft lbs. Then it is also staked. A new nut is recomended each time it is removed.
Cheers Scott

we are talking d2 here arnt we.

No sign of oil on the wheel so far. Will check the the diff oil again tommorow and the wheel nut probably all wheel nuts just to make sure they staked properly