I also went and just bought the 13-14 dollar rear differntial sensor. It was hard to get off and had to use some JD bolt remover, Also my exhaust runs around and on top so I could only work on the unit in the morning after my truck sat overnight. But after all that the problem was solved. Now only a dozen more to solve.

 

I have a 99 F150 2WD. My ABS light went on the other morning. I have noticed that after it came on my brakes grab hard if I have to brake fast. I have 108,000 miles on it. Would that sensor cause the grabbing? I have never changed the pads on the rear wheels and have noticed a squeak back there when braking. I plan on changing them soon also.