I’ve had my truck since April. I have used the 4x4 many times at low speeds, for short distances. Everything has worked as it should. A few days ago we got a little snow and it was enough to cover the road. I put my truck in 4x4 on my way home from work. Everything seemed to work fine but I am experiencing a noise that i’ve never had in any other truck or Jeep (although, this is my first SD). At speeds above 30-40ish, when I let off the accelerator I get a constant noise that’s hard to explain. It almost sounds like a constant rubbing of two steel plates. It’s not terribly loud but certainly noticeable. I don’t feel any vibrations or grinding, just the noise. When I apply a little throttle, it seems to go away. Let off the throttle and coast, it’s back again. Again, it’s constant and consistent.

I was hoping that something just needed to lube itself up internally but i’m starting to doubt it. Any thoughts other than the obvious: “take it to the dealership”?

 

Possible you hubs are still locked or just one. This can happen if you turn off 4x4 as you killed the engine and did not have enough time to pull out of 4. Try this at the beginning of next drive put in 4Hi and drive 1/2 mile then turn off 4x4 back to 2Hi for the duration of your drive. See if it went away. Something's it takes awhile for the vacume to pull the hubs back to free wheel.

 

I and others have this issue:
https://www.ford-trucks.com/forums/1...ing-noise.html

 

OK. Thanks.

 

Is the front slip yoke and CV's on the front drive shaft grease-able?