Murphy,
Smart thing paying attention to l & r turns and noise being equal.
That trick works on front wheel drive cars real well, and rear wheel.
Sharp zig zag while driving, isolates noise of which bearing is bad in the wheels.
Sound changes while zig zagging.
So, does it make more noise under acceleration?
Or does it make a different noise under de- acceleration?
If it changes, then the issue may be the ring and pinion?
Worth checking, cause its easy.
John