I´ve gotten the 231 pretty hot on occasion. Patchy snow and ice. I´ve gotten so I leave it in 4X, unless the road is clear for more than mile or so. Got caught in 2X once, with a Semi coming up behind me fast, while traveling sideways, up the intetrstate. Hit the gas, found out, I was on a sheet of invisible ice. Since then, I figure, wear and tear on the transfer is the price, I´m gonna have to pay, for a little extra traction.
But I have noticed the moisture, falling on the transfer, turned to steam on occasion. I´ve gotten so I know, when it´s time to stop and let things cool down a bit. Really isn´t much oil in the 231, heats up fast.