I have a 2003 Explorer 4x4 and have what is probably a stupid question about the way the 4x4 system works. I've looked around and can't find an answer, and figure this would be a good place to ask.

When I have the switch in 4x4 auto, is it in 4 wheel drive mode, or in 2 wheel and it engages 4 wheel drive if needed? Also, if there is a heavy rain, would it help any to put it in 4x4 high?

Thanks for the information.

 

When in Auto, your Explorer will be in 2WD until the two speed sensors that are mounted in your transfer case detects that your rear wheels are spinning faster than your front wheels. When that happens, power will be diverted from the rear driveshaft to the front driveshaft until your GEM computer detects that both driveshafts are spinning at the same rate. Once it detects this, power will be lessened from the front and reapplied to the rear.

No, do not drive in high on rain covered. When you lock your transfer case in high or low, it locks the front and rear driveshafts together. These two modes sould only be used when the surface is slippery enough to allow for the tires to slip easily when you turn. Since your front tires take a different path around turns than your rear tires do they need to spin at different speeds (to keep up with each other). When you lock your transfer case in high or low, your front and rear tires can't spin at different speeds so they have to slip on the surface that they are driving on. Dirt, mud, sand and snow surfaces are plenty slippery enough to allow this to happen. Rain soaked pavement isn't. You will be over stressing your 4WD driveline and risk the possibility of excessive wear or breaking something very expensive.