AlbertaJeepZJ

Hey everyone trying to figure out vibration or light howl sound when going at faster speeds . It's a 95zj quadra trac with higher miles on it. I recently did the wheel bearings and ball joints cause I was in there and no change. Can possibly a bad tire balance can cause this? I'm starting to think not cause the noise dissappears when you let off the gas and continues when you give it throttle again. I also took off front diff cover and from what I could see nothing is banged up or shavings in the oil. What can cause such a noise?