POOPonYOU
Full Access Member
The manual and raptor supplement detail the modes quite well. The main thing you should note is that they are well calibrated, and you should trust them to do what they were designed to do.
Normal, Sport, and Weather for the road, the rest for off road.
To answer your question directly, in heavy rain/snow I use weather mode. Light rain I just stay in normal but kick it in to 4A. Make sure you stay off the gas whenever the tcase is shifting.
So stay off the gas when I switch the 4WD modes? Do I have to be below a certain speed when switching 4WD modes