Ford Repair: Humming sound front end, ford explorer 4x4, cv joints

Question
James Bond,
Last month my 1994 Ford Explorer 4x4 (95,000 miles) started making a loud humming (wahwahwahwah) sound in the front end that gets louder as I go faster and more quiet as I go slower. Differential fluid is Ok, transfer case and transmission fluid are OK. I'm not a mechanic, but handy, and I like repairing things first before the experts do. What do I check next? The Bearings? or U-joints? Something else? I'm not sure what to do. Help!.......
Thank you,
Lee

Answer
Sounds to me like, your bearings are loose or worn. Jack up the front end and wiggle the tires back and forth and see if you have alot of play in the tires. Also, check your cv joints if the rubber boot is torn, you will probally need a new cv joint. Also, bad out of round tires will make this noise.. Thanks,,,