Could be a ujoint at the wheel end.
When the ujoint gets a dry cross, rusty etc, they sometimes squeek. but only when they are pivoting.
On the steer ujoints, the only time the needle bearings are actually being rotated inside the ujoint caps is when you are NOT going straight, so when one cap (usually starts with just one) gets dry, then when the needles inside the cap move, they squeek.
time for a ujoint or two if this is the case?
Have a good look at each ujoint cap to see if there is any corrosion (rusty) residue around where the ujoint cap seal is??
If so, needs ujoint. Good idea to do both sides if they are the same age.
Can try some wd40 just to see if the noise goes away for a bit?? Not a fix, but can help in diagnosing... When u go mudding, you lube the joints with water/mud and the sound goes away for a bit...
Just FYI, ujoint needle bearnings in driveshafts turn/move all the time (unless the driveshaft is exaclty lined up with the diff/transfercase/transmission) so they will start to squeek usually at low speeds as a telltale that it's time for a ujoint change.
Anyway, hope it's just the steer rubber boot, but check the frt axle ujoints too?