2002 Chevrolet Blazer

Noises problem
2002 Chevy Blazer 6 cyl Four Wheel Drive Automatic 160000 miles

I am getting a destictive " Hum" eminating from under the front seats, the frequency and volume of the noise is directly proportional to the speed of travel, I have gone to a gravel road and engaged the front end and put the unit through some harder " Carving" type turns to eliminate the posibility of the probelm being the CV Joints, I have also raised the rear of the vehicle and ran the drive train, " No Noise" but I assuming that there was no noise because there was no " Load" on the system, The tires have recently been replaced with no change to the sound, there is also no bearing seal leaks no sloppy yokes or worn out universal joints.
Any ideas anyone?
February 7, 2009.

Hi: If the sound isn't there with the rear wheels running, check the front frive shaft, out put on the transfer case for play and front pinion bearing for play.

Let me know what you find.


The front outpt bearing on the transfer case is good, as well as the front pinion bearing.

Feb 8, 2009.