I own a 2006 Ford Explorer. It has Auto 4X4, High 4X4, and Low 4X4.
Does it have a center differential? I understand the difference between high and low 4X4.
But how does the Auto 4X4 operate?
LouA
Auto 4 by 4 operates differently in many vehicles. Some, the older ones, still have no center differential but automatically engage the 4 wheel drive as the rear wheels slip in your case. Some, with a center differential, use an unlocked system to engage it all of the time and shift the torque as needed with the lock being engaged either with a switch or when placed in low range. Mine has the second type. You can treat it like an awd car when in the unlocked mode. Do a little googling or talk to a Ford rep to see which you have. Jeep offered both types and the model determined which you got. So, it is really hard for some one to answer based upon that info. Reading the manual often gives you a clue as well as this.
This looks like you have the second type that locks in the high and low range. But, don’t trust one source.
My 2000 Blazer had a similar setup, Autotrac. Auto 4wd only engages the front axle if slippage was detected at the rear wheels. This setting allowed one to drive on wet or dry surfaces without damage to the transfer case. The Owner’s manual should explain your system.
Ed B.
The newer systems like my 4Runner and perhaps OP’s Ford are ALWAYS engaged when in Auto 4 wd. No slippage need occur. They use a Torsen ( torque sensitive ) system that varies the torque but does not wait for slippage to fully engage. Both axles are being driven all the time in this setting.
Otherwise, why even have the option ? With it not engaged, you get better economy when only in 2wd.
Older models actually engaged the part time lock system when wheel slippag occured. They had no open center differential.
This is covered on page 232 of your owners manual. Do you have it? If not, download it from Ford (it’s free).
http://www.motorcraftservice.com/pubs/content/~WO6EXP/~MUS~LEN/41/06expog2e.pdf