Leaking front diff

I would suggest cleaning off the oil with a rag and checking to see exactly where it is coming from bit hard to work out from your photos as they are not very clear . After wiping off the leaking oil see where it is running from .
Maybe a leaking diff seal and a leaking sump plug ??
If so , fairly simple replace parts to repair .

Hi Damian

Looks like a Pajero, correct me if I'm wrong.
Make sure the drain plug is tight, If it is it looks like the diff seal is leaking.
Depends where you are as to if it is serious. Oil leaks always look worse than they are as the oil spreads a long way.
If you out & about & have oil keep it topped up until you can get the seal replaced
Good Luck
Paul

G/Day Damien, Looks like the diff seal, which could be leaking because the flange nut is loose

.Also the front bearing needs to be checked, in case something is wrong there as well....Unless its dripping down from above?.

Climb underneath ,and as mentioned clean it all down, go for a run and have another look, unusual for those models to leak around there ,ive had a couple and they have always stayed dry.

Good Luck ,

Cheers Axle.

Damian
Although a common way to describe something, if it is oily it is oily, if it is greasey the ot is as a result of grease. Quite different to me, and oil I buy is thin and grease is semi solid like. Identifying the difference helps in diagnosis.
The oil looks to be dark in colour unlike diff oil, if it smells like engine oil and DOESN'T smell like diff oil then I would say it isn't diff oil. Yes a diff can leak but if it's drain plug is not sealing it will simply drip off that point. A leaking diff seal will not see the oil migrate forward over the diff case and bell housing etc.
It appears the oil is spread far and wide and is therefore unlikely it is from the diff. Most likely from sump plug or an engine oil leak. The smell of the oil will reveal that. Hot engine oil travels well as mentioned above.

If a quantity of oil has left the diff, then it's level will be less, ie, found when checking level.
The diff pinion flange nut probably is not the issue. If the internal sealing for the diff flange is not correct then diff oil may come out past the splines, the pinion nut has no bearing on the seal leaking, unless it is extremely loose. If that were the case then the diff gears would be stuffed. "Caution", most pinions have a collapsible spacer for correct bearing preload, if for some reason you were motivated/encourage/conned by advice here, to tighten the nut and tightened it past it's correct setting, then you WILL stuff the diff pinion bearings. Be careful and seek proper advice if the nut requires attention. Unless skilled in diff work a novice should not try.

check the diff breather might be blocked