I'm hearing almost like a high pitched tweet, as I press on the gas. It will go away as I maintain a speed and then will often come back, as I accelerate. Is this the speedometer cable? Is this an easy fix? Or is it something else, from a rear wheel or rear end? I'm in the middle of trying to resolve the ABS from kicking in at every stop and didn't know if this was related.

 

I dont think the ABS would have anything to do with it. I am having the same problem with my rear end. Check out my thread https://www.f150online.com/forums/19...-question.html

From what I have read on here it could be a few different things. Depending on how severe the problem is, you can try to change the delicious smelling gear oil in the diff to see if that helps, if not then it could be the pinion bearing, the gears itself or U joint. Give them all a check or have your mechanic check it out if you don't know what your looking for.

Some people on here have gotten all new axles because there previous axle is toast.

Good Luck

D