Jeep Wrangler

2001 Jeep Wrangler. 6 cylinder. 66xxx miles, 4 inch suspension lift.

I was on the highway a couple days ago, was traveling about 70 mph, suddenly there came a sound that sounded almost like a Tornado siren, a single LOUD tone coming from my front left wheel. The longer I maintained my speed the louder it got. When I slowed down to about 55 mph, the sound stopped. I have NO idea what is making this sound, or why. Could anyone please tell me what this might be? Is it a bearing, a U joint or.?
March 17, 2007.

Does the noise get louder as you accelerate?
Is the noise still there if you push in the clutch or put it in neutral?
In other words, does the noise correspond wiht the speed of the engine or the speed of the vehicle?
Is the wheel hot?
Can you jack it up and spin the wheel to check for smooth operation?

Good hunting and let us know. : )

Mar 17, 2007.
It doesnt seem to correspond with the engine, it does however seem directly connected to the wheel rotation, because when my speed slows the noise lessens and eventually disappears. I did look at the back of brake rotor immediately after I got home, and it was hot enough to cause a misdirected spray of penetrating lubricant to steam or smoke when it touched it.
The noise is still there when I press in the clutch pedal. I havent had the chance to jack up the car to check free rotation of the wheel, but the car doesnt pull to that side when rolling, so. I dont know.
I have a sneaking suspicion that it may be the u-joint for the front right axle, or at least the bearing in it.

Mar 18, 2007.