I have a 2016 Superduty.
I was sitting still in the drive, engine running and Tx in Park.
Following the manual's instructions I put the Tx in Neutral, turned the 4x4 **** to 4x4 high and then to 4x4 low. I then pulled the **** to engage the electric locking rear diff. I put the Tx in Reverse with the foot still on the brake and then as I gradually lifted pressure off the brake pedal (I think) and started creeping, I heard a medium pitched grinding; not so much like spur, helical, or hypoid teeth grinding; more like cog gears. I stopped the truck and disengaged everything. Later in the day while on dirt I put her through her paces proper and all was fine. I guess I'd like to just know, given that this is my first 4x4 with so much electric shifting, what actually happened. If you are pretty sure of what I heard but are puzzled by the sequence, I could have the order of things a bit off as my brain was just about wiped completely free of all memory when I heard that sound so I may have the order of what I actually did, wrong.
Any ideas?
Thanks,
Ed

 

What are you trying to do ?

 

Shouldn't hear anything at that slow speed.. My guess is something didn't lock in... prob fine. Go find some dirt and try to break it...

 

Your description reminded me of the time I shifted into gear before the transfer case hit 4-low. That started spinning the transfer case before the gear was locked in, which caused some harsh engaging of the gears. Did you wait for the 4-lo light to come on before putting it into gear?

Also, the E-locker is completely separate from the transfer case. You can lock the rear differential in 2WD or either of the two 4WD selections without issue. The transfer case doesn't care because it's not involved, the action is confined to the rear differential.

 

Sounds very reasonable Tom, and also very likely. I am used to knowing when the transfer case was in gear because it was a manual motion of a floor shifter; kind of hard not to know when it is in. I may not have waited for the indication on the dash to tell me that the case is now in gear.
Electronics !!
Thanks Tom.