2000 windstar growling

Hey guys, Long time reader first time writer! (bare with me)
My windstar started making a growling or kind of like a intense low pitch humming a couple weeks ago. The growl seems to be comming from the front of the van and you begain to here it at about 30 mph. The noise does get louder the faster you go but stays consestant with speed. It dosent change during a shift our with rpm. You can actualy feal a vibration on the floor board from the noise. My wife and I noticed it right away but I have to point it out to some people and it does seem to be getting worse. My first thought was a wheel bearing, however, when I jacked up the front and checked them I diden't see any thing wrong. Maybe there is a better way to check them then just turning the tire and looking for slop. With that can you repack wheel bearings?
I also looked at the tires and brakes, the tires are about six months old with 10,000 mi and I had the front roaters turned, with new pads all the way around in jan 2005 . I wanted to check the cv but wasn't sure how. So I just kind of looked for slop their too, I didn't see any.
Any how for some dumb reason I have owned three windstars and have done ALOT of repaires on all of them. Including a new trany in one. So I am scared to death of another major problem. I would be greatfull for any help on this and hopefully I can repay the fourm with my unwanted expierance on ford windstar problems!

Hey guys, Long time reader first time writer! (bare with me)
My windstar started making a growling or kind of like a intense low pitch humming a couple weeks ago. The growl seems to be comming from the front of the van and you begain to here it at about 30 mph. The noise does get louder the faster you go but stays consestant with speed. It dosent change during a shift our with rpm. You can actualy feal a vibration on the floor board from the noise. My wife and I noticed it right away but I have to point it out to some people and it does seem to be getting worse. My first thought was a wheel bearing, however, when I jacked up the front and checked them I diden't see any thing wrong. Maybe there is a better way to check them then just turning the tire and looking for slop. With that can you repack wheel bearings?
I also looked at the tires and brakes, the tires are about six months old with 10,000 mi and I had the front roaters turned, with new pads all the way around in jan 2005 . I wanted to check the cv but wasn't sure how. So I just kind of looked for slop their too, I didn't see any.
Any how for some dumb reason I have owned three windstars and have done ALOT of repaires on all of them. Including a new trany in one. So I am scared to death of another major problem. I would be greatfull for any help on this and hopefully I can repay the fourm with my unwanted expierance on ford windstar problems!
hmm sounds alot like a wheel bearing.does the noise change when you do kinda like a slalom(when you turn the wheel left and right while driving down an empty and safe road)at around the speed you start to notice the noise?this will load one bearing at a time while unloading the other side.if the noise changes during theses turning maneuvers then you have a bad bearing.keep in mind to be very careful as these vans have a high center of gravity so you dont want to jerk the wheel to fast.
worn inner cv joints usually only make noise upon initial acceleration while worn outer cv joints usually only make noise during turning, its a clicking type of noise to, so i think it is safe to rule out the cv joints.however i would not rule out the tires just yet.are you familiar with wear patterns on tires? ie.. cupping/feathering?both of these conditions can cause a noise similar to wheel bearings.

Thanks for the reply. Here is the rest of the story on the tires. Back in march I was on vac with family when I busted a belt on the front tire. Due to financing I could only get one tire. The back two were good anyhow, and the other front one had some miles left on it. A week before the noise I bought a new tire for the front. Even though I purchased both tires at a wal-mart, they do have diffrent tred. I just bought the cheipest they had. I have took the van back there twice to tell them I thought it was there tires. Both times they rebalanced them checked them over and said they were fine. One fella working there did mention the diffrent tred and said that could cause a noise. I thought he was full of it and went on my way. Now I am not to sure!
I can't notice any wear on the tires yet and the alignment seems good. What exactly should I be looking for in the feathering wear?
Also there is the slightest change in the noise when on a long turn though it is very hard to detect.