Is it normal for a chevy trailblazer 02 to make whistling ooo-ing sounds

[Anna P]

while on 4x4? Thankssss.
When on 2wd it sounds fine but driving on any 4x4 driving things (4hi, 4lo, etc). is the only time it makes sounds. When driving slower you don't hear it as much only slightly. But when it drives quicker on normal streets it makes strange sounds.

The two front tires and the bumper just got changed. Could that be why?
So can this happen when it's only turning or when it drives straight and turning?

This happens more often when I am just driving straight.

[boogie_4wheel]

I'm guessing that your hearing the gears in the transfer case and front axle whining. They are doing this because of the torque that is applied to them. You will put pressure on the drive train when you make a turn (your front tires will spin faster than the rear during a turn) and this will cause the gears to whine slightly.

No damage is being done, it is just something that happens. It is usually more noticeable while in low-range because of the increased speeds that the internals are spinning in the transfer case.