Humming noise Part2

Some people are hearing noise when turning and having 2 to 4 wd shifting problems. My problem is the same as Jdizil on pg. 2. I get a tire "big knobby" road noise when I accelerate and it quiets when coasting. Noise also goes away if I hit a highway bump as the body goes up the sound goes away and as I return flat, tire noise comes back. Sounds like it's the driveshaft??