My 06 F150 King Ranch with 111000 miles has started making a whining noise comming from the Rear Diff. Any ideas? Fluid change needed?

 

If it's never whined before, I would say that there is a problem. What speeds are they whining at?

 

Hwy speeds mostly. Gotten worse over the last two weeks. I'm going to try a fluid change this weekend before I consult the dealer if I do not get any good advise on here....

 

maybe wheel bearings might be going out.. i just replaced mine and my truck has 91000on it. go on and replace bearings and seals. if ya want get a mag hytec dif cover i love mine and put some royal purple gear fluid in it. as i did in mine and it made a ton of difference