Originally Posted by KenLyns
Out of curiosity, since the T100 has a stick-shift transfer case, why can't the truck be flat towed as-is with the transfer case in N?
Manual transfer case should be okay as they are usually splash-lubed (I'd verify with a Toyota tech to be sure)
To the above questions, manual trans are splash-lubed just like the diff. There is no pump. If any of the shafts are spinning, lube is getting where it needs to go.
On autos, the fluid is primarily a hydraulic fluid to operate the clutches, but it is also the only lubrication that the rotating assembly gets.
The fluid is circulated by the pump, which is driven by the input shaft. They are not splash-lubed... that would cause aeration of the fluid and it would not work in the high pressure circuits.
Put the trans in neutral and coast downhill with the engine off or at idle and you're spinning your trans either without, or with insufficient lubrication.
SOME autos can be safely flat-towed in neutral, but not Toyotas.