I have a 2004 Frod Explorer EB with ~78K miles. It seems that when I am driving at or around 70 mph I start hearing an intermitten loud whirring noise coming from the rear of the vehicle (at least I think it is the rear). At the same time as I hear the sound it is like the vehicle gets a tug or like a brief gust of wind hits the car and it very briefly slows. I can't see any change on my speedometer but I can feel the hesitation. Any ideas as to what this might be?

I don't know what the sound could be, but the hesitation could be one more shift, to keep it ridin' easy, without too much strain, does it feel like it revs lower afterwards? If so, then it sounds like there's one more gear in the tranny than you thought there was.

There is a TSB on those models for noisy rear wheel bearings in the rear. Is it still under warranty?

I'm not sure, but if you check www.mycarstats.com (http://www.mycarstats.com), it should help.