I have an 04 Chevy Trailblazer that is making a whirring front end noise. I replaced all the brakes and rotors, no help. I changed the left front hub assembly thinking maybe it was a wheel bearing, no change. When I turn the front left axel shaft by hand it makes a small ticking sound, and it sounds like it's coming from at the back of the shaft at the differential. The CV joints are tight no real play in them. I'm stumped as to what it could be, any suggestions will help thanks.