I am new to this forum and used the search already. It found me lots of information about the different 4WD modes but I did not find an answer to my question yet.

Well according to the manual you can use the 4A mode at any time, any surface dry or wet. I know that the 4WD should be used in slippery conditions only and not on tight curves but I tried the 4A out on a normal drive.
To me it seems it shifts pretty rough and there is some howling sound for a while after a curve and when starting. It's not all loud and does not sound like something broke but still weird as it should not go on 4WD under the conditions I tried it.

What are your experiences?

Eric

 

According to Ford, On my 2010 in 4A, I notice no real difference from 2H, unless the road requires the 4A to kick in because of loss of traction.

 

I can feel the extra load on the engine switching from 2High into 4Auto.

Very slight but you should notice it if you set the cruise at (say) 35mph on a flat road and switch between the two modes. 2H gives better fuel economy due to less strain but that probably takes laboratory instruments to measure.

I run 2H all the time other than in the rain where it's easy enough to rotate the switch to 4Auto. I rarely use 4High except on very loose surfaces and only use 4Low to make sure it still works and occasionally when hooking up my camper as the truck crawls in that setting and I can hit the coupler easier.

My Explorer only has 4Auto, 4H, and 4L and has been running in 4Auto for 120,000 miles.

-- Chuck

 

I agree with all you said. But did you heat that noise when in 4A and going through a curve? It starts in the curve and stops like 3 seconds after it. Kinda weird it happens even when no 4WD is required.

 

Probably the front/rear differential (?). I'll have to listen more closely. I don't recall any noise in my Explorer which I drove for 5 years before it went off to college with my daughter 4 years ago.

-- Chuck

 

OK, just to test, I drove around all day in 4A. In town up to 25mph, left turns, right turns, with no noise. In a Lowes parking lot, made sharp left and right turns at about 15mph and no noise. All surfaces were hot and dry.

Also while in the parking lot, shifted into 4H made sharp left and right turns at less than 10mph, the noise it made sounded like the front wheels were grinding. This, I would guess, is because there was no give(slippage) while in 4wd. Shifted to 4A, noise gone. Shifted to 2H noise was gone.

Could you have an issue with your traction control system that is not allowing the 4A to operate as designed?

 

Thank you so much for testing this! When I go to the dealer I will ask for someone to have a testdrive with me and they will have to explain it.

At higher speeds there is no noise noticable. Only at lower speeds like how you were testing.

I will keep you updated.

Thanks again!