Ball Joint problems of the 2004 Ford Explorer Sport Trac

I have experienced accelerated front tire wear, and associated noise and vibration on this vehicle, with current mileage at 37000 miles. I have had the wheels balanced religiously every 5000-6000 miles since I bought it. I first noticed the wear and vibration at about 25000 miles. I took the vehicle in to have the wheels balanced and was told that the ball joints were loose and out of specification. I then returned the vehicle to the dealer to have the vibration and wear problem addressed under warranty. The dealer told me that there was nothing wrong with the vehicle, and that the noise was simply due to tire wear. When I indicated that a third party shop had found loose ball joints, the dealer stated that they were in spec, and then recommended front end alignment which I had performed. The vibration and noise from the front tires continued after the alignment was done. At this rate, I will have to replace the tires and likely the ball joints on this vehicle prior to reaching 40000 miles. Several other complaints to NHTSA are very similar to my experience with this vehicle.