The Rusty Gear

At highway speeds, when I step on the gas pedal, I hear a high pitch grinding noise coming from the rear. It stops when I let off the gas. Could this be my rear wheel bearings about to go? Driveshaft? I've checked the U-joints and they seem to be fine.

Flamedx4

I would think not. I would suspect the setup in your rear diff, or your u-joints, or even the trans output shaft bearing, something more like that. I'd look at the driveline angles closely. My experiences with bad wheel bearings is the sound is there anytime you're rolling, throttle didn't make any difference.

Bad bearing sound.... imagine taking a coffee can, put a marble in it. Swirl it around so the marble goes around and round, makes a nice smooth metallic sound. Now, toss a pinch of salt in there. Swirling metallic sound but not smooth anymore, kinda grindy. That's about what a wheel bearing going out sounds like, only more solid (less "tinny" than the coffee can.)

E1

Check your fluid level and condiotion in the rear end. I doubt it's a bearing as well. Most of the bad wheel bearings I have ever hear made noise under the stress of turns and cornering not under acceleration.