The rear end squeaks on my 03 Screw 4WD when putting it into gear with the brake on and putting on the brakes while backing up slowly. Some times it will do it when you "bump' the accelerator when idling along.

It's not a brake noise it's definitely a suspension noise and I think it is the springs.

I know that you cannot oil a spring but would silicone or dry Teflon be OK to use to try and isolate the problem?

 

Check your bed attachment bolts. My friend had to take his 03 Screw back to dealer because they did not torque these down properly or they forgot to put in the rubber washer/bushings. His made the same noise before the dealer fixed.

 

Your probably hearing the brake pads pressing on the rotor when your foot is on the brake. Most Ford pads I've come across on other fomoco products use a pretty hard material that will
make that sound. As far as the spring noise I didn't think of the dry lubricant but spraying the small pads between the leaf springs and the bushings with WD-40 helps until the rain washes it away. I'm thinking of taking it back to the dealer once it starts getting bad again. It's a shame a new FX4 sounds like a conastoga wagon going thru the drive-up window at the bank!!!!!!