Whinning noise??? Need HELP

[99t/aman]

So i have a 2003 cc/sb 7.3. I have a whinning noise only on acceleration any where from 30mph up to 70mph, changed the diff. fluid about 10k miles ago. Need to know what you guys think it is?? To much play in the rear gears or what?? It is hard to tell if the noise is from the front or rear of the truck cuz you hear it all through the cab. Let me know please

[precisionpowercleaning]

I am having the same problem. I thought it was tires at first but ruled that out. I only hear it under acceleration. Goes away on decel. Wonder if it is pinion or carrier bearings, maybe gearset? Just checked the rear diff lube and it is clean as can be??