Well my jeep seems to have a humming type/ whistle melody noise while driving. It only starts around 35 mph. if i give it gas it kinda speeds up but goes down but is really loud around 45 where its the high pitch noise. It seems to be coming from the front. While at 45 i put it in Neutral and keep the rpms up while its doing it and get the engine to turn more rpm to see if its a pulley. In which the noise goes away which tells me either dealing with brakes or a bearing going bad some where. Any helpers?

 

Sounds like your front wheel bearings/hub assembly. Replace em with quality ones made by Timken

 

This describes my jeep to a T. So your thinking its the front u joints?