I'm having a t-case issue with my 03 Edge 4x4, 5-speed. It's happened twice this year. My wife and I were driving across my mother's land both times and I decided to see how the 4wd worked out on it. The first time I switched into 4wd, I just pushed the clutch in, sitting still and went from 2wd all the way to 4low. Nothing happened, it made some "clicking" noise, but never went into 4low... I moved the switch to 4hi and it went into it, then, after that, I moved it back to 4lo and started rolling a little and it went into 4lo and actually worked.

Now, going from 4low, back to 2wd is a PITA! It won't even go into 4hi, once it's in 4low.... And, this makes no sense to either of us, we have to be on, flat, level ground, before she decides it's time to come out of 4low. I've done research on it and can't seem to find exactly what's wrong with it. I thought about rebuilding the t-case shift motor, but to me, I'd just buy one, no more than it costs, if that's the problem?

Oh well, I've only used 4wd twice in a year, so no biggy if no one knows what the problem is, but I'd like to eventually get it fixed.

Thanks!

 

4WD low has a high gear ratio, so can be hard to change on a hill, remember the transfer case is connected to the wheels, clutch does nothing to take pressure off that, thats between engine and trans only.
There is an electric transfer case clutch for "shift on the fly" but it doesn't always release pressure from wheels.
And brakes just lock it in gear because wheels are locked.
I.E. park on a hill in 1st and turn off engine let 1st gear hold your position, then try to pull it out of 1st, foot on the brake NO CLUTCH, can be very hard to do, even on a slight hill.
This is why level ground makes it easier to switch out of 4WD low

So not to unusual

Shifting into 4WD low may also require a roll forward or back when on a hill for the same reason, the gears need to mesh and if not aligned then they need to move slightly one way or the other, on a level surface there is enough play in the drive line to do this, but on a hill the alignment may need to go in the direction of the hill and can't because wheels are locked and all the play is gone.

4WD high is a much higher ratio so you hardly ever run into this.

Could be shift motor is starting to wear out or slightly out of adjustment, yes there is an adjustment on the motor to align motor sensors with transfer case shift positions.

This thread shows how the shift motor works when you chose 2WD, 4high and 4low: How to: Rebuild 4X4 Shift Motor | Ford Explorer and Ranger Forums - Serious Explorations

You see the "sensor wheel" in the motor, that moves with the motor and transfer case shift shaft, when wheel gets to a certain position 4WD module says "that's in 4Low", it doesn't know if transfer case IS in 4Low it just knows sensor is at the right position for 4low, which is the adjustment.
Light will flash if it can't move sensor into that position, so try rolling forward or back if that happens, so motor can turn all the way into selected position