Have a 2003 f550 can't pinpoint a meowing/squeaking/Aretha Franklin sound penetrating the cabin at 25-45 mph. Had the drivers side wheel bearing and pinion replaced to no avail.
Literally sounds like "rrreeeeeeeerrreeeeeeeerrreeeeee" wheel speed dependent.
disappears when stopped or traveling at freeway speeds.
Its so annoying, anyone have insight?

 

squirt some stuff on the carrier bearing and see if the noise stops, or changes. If it does.. probably time to put a new one on. if not?? Kinda tough without being there.

 

Its not the brakes is it? If you press the brake pedal does the noise change?

 

U-joint in the drive shaft?

 

Seconded. Typical u-joint sound.

 

With out more info on the truck like trans type, mfr., wheel base, ETC. I can only guess but just from what you have said see below.
Check to see if the drive shaft is "in time" at the slip yoke could be off one or two teeth that will give you the high pitch noise you describe. And the worn "u"joint theory as well. Something else to check is out put and in put yoke in and out play and bearing run out!

 

2003 ford f-550 super duty with a triton v10. 17' high cube with lift gate. Dana S135S rear end.