Outer Limits 4x4 Board

Hi, thought I'ld change the oils in the 80series as I've not had it long and don't know when they were done last. Got to the gear box but when I opened up the FILLER plug, oil started to pour out. Which didn't make sense as it was the filler plug not the drain. Thought there might be water in the gear box so opened the drain plug and collected a little oil out to see if there was any water, but there was none. How could there be oil in there above the level of the filler? Never worked on an 80s before so some help would be greatly appreciated .

either:

your seal between the transfer case and gearbox is blown and is pumping oil out of the gearbox....

OR

Someone overfilled the damn thing by filling it on a slope

was the level in the transfer correspondingly low? it is uncommon for these boxes to swap oil between them, the likely schenario is that it was filled on a slope or over-zealously, deliberately overfilled. it won't do it any harm but can cause some leakage on steep hills.