I have noticed a high pitched humming noise coming from the back of my car. It is speed related. I start to hear it at about 45mph and it goes away at 75mph. It also stops if I turn right.
My front wheel bearings were replaced last year and the soun definitely sounds like it's coming from the back of the car.
Does this sound like rear wheel bearings? Diff? Something else?

Help me diagnose this:help

Hey Dave.

That could be a diff noise or a wheel bearing really. Wheel bearing noises usually vary with road conditions. If the noise is constant on a bumpy road, its probably elsewhere.

In your case, I'd rebuild it since its an LSD. So three bearings, three seals and a new crush sleeve.

when mine went bad it sunded like there was a helicopter in my back seat at about 65 -70 mph

OK, well I guess I'll drain my diff and see what it looks like.
And maybe I'll be doing rear bearings soon. Yikes!