Changing Rear Diff Fluid.

[Iceman83]

Will changing the diff fluid stop the rear end from making a "whirring" noise? Explorer has 173K, and the diff. cover is wet. Or do I need a new rear end?

 

[IZwack]

Changing the fluid probably wont make a difference. At 17x thousand miles, the bearings in the rear axle probably needs to be replaced - which typically happens maybe at around 100k miles for most 2nd generation Explorers.