4WD high works fine. When I go into 4WD High, then neutral, and then 4WD Low, I do not hear the transfer case engage. I know on my other two previous Excursions I could clearly hear the t-case engage. It stays in 4 high, this I am certain of. I typically use Low to crawl down my driveway when we have snow. Suggestions?

 

You are sitting still when you shift into 4Lo aren't you? I have had trouble with mine shifting unless sitting dead still.

 

when you shift to 4low do you have your foot on the brake and the transmission in neutral?

 

More so the trans in neutral......it might have to roll a bit to engage

 

Yes, at a complete stop, foot on the brake. It stays in 4 high if I go back to drive.

 

Straight from the factory manual:

"If equipped with the Electronic Shift 4WD System, and 4WD Low
is selected while the vehicle is moving, the 4WD system will not
engage. This is normal and should be no reason for concern.
Before 4WD Low can be engaged, the vehicle must be brought to
a complete stop, the brake pedal depressed and the transmission
placed in N (Neutral)."

I believe it is the same process to get out of 4WD Low.

Manual link: https://www.fleet.ford.com/maintenan...ls/results.asp

 

That is exactly what I am doing. This is my third Excursion so I am quite sure I am doing it properly.

 

Crawl under truck, beat on transfer case with rubber hammer?

I've never read up much on the t-case, but I think it does take some sort of oil. Maybe it's low on that and won't shift without proper oil levels?

 

Since you know the process well, I'd look at the shift motor for the T-case to be sticking. I'm guessing that is the next place to look. I think there is an actuator connected to the motor that can stick too.