worrisome rear-axle noise
did some search on this topic first but have not found a satisfactory resolution ...
i hear a low-frequency sound from the rear axle at low speeds that goes "WOO-WOO-WOO", as opposed to a continuous grinding or whining sound (as i've previously experienced with my differential before).
since my car is a 5spd manual, when i hear the sound peak, i place the car in neutral, and the sound is unchanged, and its frequency is directly proportional to vehicle speed.
from the frequency of the sound and vehicle speed, it seems that more than one "WOO" sound is made per revolution of the wheel. I would say about 2 or 3 per revolution.
I also get a noticable vibration at speed. Jacked up the rears and brought my rears up to speed and the vibration was there. The wheels have recently been balanced though.
could this be made by a bad CV joint? I noticed that the CV joint has 6 internal lobes, which could be producing the 2 or 3 sounds per wheel revolution.