Kinda figured it was in the rear diff. It has done it since I bought it at around 90k. Now around 120k and it hasn't gotten any worse. I'll change out the fluid and roll with itCheck this thread:
2003 Ford Explorer Rear Differential Whine
I bought a 2003 Explorer with the V8 and 3.73 rear end. I has a bad whine that starts at about 50 MPH. It is under warranty up to 60,000 miles so I can get it fixed but reading the forums online it seems that Ford has not figured out exactly how to permanently fix the problem. Does anyone know...www.explorerforum.com
A lot of users have the same rear diff whine as you're describing, I developed one years ago, a fluid swap seemed to quiet it down for a long time until it came back again, drove like that for a few more years and decided to rebuild once I was getting the whine upon acceleration, as well as deceleration. I also had 200k+ on it at that point so +1 on new fluidKinda figured it was in the rear diff. It has done it since I bought it at around 90k. Now around 120k and it hasn't gotten any worse. I'll change out the fluid and roll with it
