The transfer case is designed so the lower internal shaft is the one that turns when you tow it. That means it's spinning in the lube, transfering oil to all of the gears. The transmission is backwards. The output shaft, the one that turns when it's towed in neutral, is on top. It does NOT rotate in the oil. It only lubes when the input shaft, the one that goes to the engine, is turning.
I towed many, many miles with no problem but on a long haul, Jackson MS to Houston TX, it finally had enough. I suppose if I stopped every 100 miles or so and started the engine, let out on the clutch in neutral to spin the lower transmission shaft, I would have been ok.
From then on I towed with the xfer in neutral, transmission in 4th. The reason I didn't use 2nd or 3rd as recommended in the owners manual...I figure if the transfer case jumped in gear I'd much rather the poor ole 1.3 Liter would tolerate the highway speed 4th gear rpms better than the 2nd gear rpms
Loved my Samurai, accidentially sold it last may...