David Smith
Full Access Member
I will try the swerving thing. If by frequency you mean how often then it does change. It does change with speed, but it does not really get any louder. It is also not similar to the noises that a mud tire makes (the faster you drive, the higher the pitch is). It is just as loud at 20 as it is at 60. The pitch never changes, but the woo woo noise gets faster the faster I drive...That's a bearing noise. If the frequency of the woo woo woo's gets fast with vehicle speed and not rpm, then it's not engine related. It will be a bearing that is from the output shaft to the wheels.
Try swerving left to right and listen for the intensity of the woo woo woo lol to change. Swerve left and it goes away or softens its he right bearing vise versa. If it doesn't change, it'll be something in the rear. Output shaft bearing pinion bearing rear axle bearings etc.