First thing I'd do is check the tire tread to make sure there is no cupping. In other words, make sure the tread is in good to excellent condition to rule out road noise generated by the tread. The tires can be close to worn out - - that doesn't matter. They just need to be in good physical shape so it's not the rubber mistaken as making noise on asphalt.
If the tread checks out, lift the wheels off the ground and spin them. Listen or feel for any vibration coming from the bearings. Spin the wheel and grab hold of the coil spring. The suspension coil spring has a tendency to increase vibration amplitude, so if you hold the spring while wheel is spinning, you may be able to feel a vibration. = Bad bearings.
Also, grab hold of the wheel (while jacked up) and grab it firmly on top and bottom with both hands. Shake the wheel, pull on it. Feel for any free play.
Remove wheel and spin the hub by hand. Try feeling for any vibration as you hold and spin by one of the wheel studs. Hold the spring at the same time & try and feel for vibration. This may be difficult because you have a 4x4. If you feel enough courage, jack up all 4 wheels (very securely) and run engine at idle while in drive to get wheels to spin. Please be very careful if you exercise this option.
Saturday, February 21st, 2009 AT 7:04 PM