Winning noise in rear end i think??

[Josh Morningstar]

When cruising and just barely on the loud pedal there is a constant winning in the rear let off pedal and stops until it coasts to a stop or crawl then goes from wine to a rumbling, crunching type feel and noise. Any clues would greatly be appreciated. Thank you in advance. Sorry 03 Expedition Eddie Bauer 5.4

 

[Hamfisted]

I would drain and inspect the rear differential fluid. Look for metal chips or shiny particles in the fluid. Sounds like your differential is coming apart. When's the last time you checked the fluid level ? There is a factory TSB bulletin out that says upgrade the fluid from 75w-90 to 75w-140 . If you "had" a limited slip differential ( Axle code H6 on driver's door tag...), make sure to add the LSD additive. But once it's making the whining noise and other noise you describe, it may be too late.

 

[Josh Morningstar]

Yea after researching this all morning I'm going to drain and clean rear out and inspect it for anything looking like it is about to fail then I'm going to put new fluid in and a bottle of the friction additives and see how that goes. But my awesome luck I'll waste my money and time just to turn around and replace the clutch and bearings in the rear cause apparently they are known for those to be a contender in the rear shudders and whistling, howling noise. Which it will be a good thing once I replace it cause then its done and hopefully good to go for the 100k!! Thanks for your help on this. Have a great day.