My FORD E250 SUPER CARGO van makes a strange, dry sounding whine when accelerating

Could be several different things. Could be transmission, wheel bearing, tire issue or rear end issue. Might want to have some one look at it a little closer before it lets you down.

Sounds like a Pinion Bearing. Growls all of the time, louder when accelerating, changes when decelerating, a road- speed sensitive noise that is no different no matter which gear regardless of speed. Wheel bearings are usually speed sensitive and there's usually (but not always) an axle seal leak. Transmission noises will change with gear changes.

I drive a 2021 econoline 250 to deliver auto parts. When you go above 55mph, it sounds like there's a ghost in the cargo compartment throwing things around, even though it's empty. It's loud and it's disturbing. I thought maybe they serviced the transmission incorrectly (133k miles on it). They don't have a transmission dipstick in the engine compartment anymore, the owners manual says, take it to the dealer (idiot). Geez. No sounds at lower engine rpms, nor when you put it in Neutral and rev it, so it's not engine. I thought under-serviced transmission maybe, but without a dipstick, I can't fix that. So, just drive slow.