I've never heard of squealing axles, but then again the bearing is more of a rumble moan. But directional preference usually means bearings. The shaft/boot would not be sensitive to a articuar direction and both left and right turning would cause the boot to compress and expand in either case.
BTW - If anyone needs bearings, I have them! My company makes them.
I can sell you one or two if you need to do both sides. Just PM me.
