nj, i too have had the same issue in my 2010. the place i had my leveling kit installed at a local shop and they messed it up somehow. ford told me they had seen 10 or so break in the last few years but mine was the worst by far. i asked if its a part that breaks alot or if its something that just a faulty install of something else could cause, they said they dont just break. but it sounded like a set of 35s roaring down the road and it only would make the noise if you were going over 30mph. i had it replaced for 298.10 including the labor since its out of the warranty now. if they replace the part it should fix your problem.
2010 F-150 XLT Supercrew, 295/70/18 Trail Grapplers, Tow Mirrors, 30% Front Tint, 20% Back Tint, Edge CS Programmer, 2" Tough Country Leveling Kit. Kobalt low profile tool box. Magnaflow SI/DO with 3" rolled stainless tips. More to come.