Nulu and all,

I guess the confusion is solved if I am understanding the bearing design correctly.
Each axle side has a pair of bearings, see screen shot, I call them 1,2 (Left Wheel) and 3, 4 (Right Wheel).
No matter what bearing, balls or rollers.... each one of the bearings is responsible to keep the axle in position relative to the 2 side forces (force during left turn and force during right turn)
For instance during a right turn the rear of the car wants to move to the left
This will affect the Left Wheel (Bearing 1/2) but also it will affect the Right Wheel (Bearing 3/4).The main load/grip will be on the Left Wheel at a point when the Right Wheel will be in the air and there will be no load on Bearing 3/4) but up to this point a right turn for instance will affect all bearings.
The load on the pairs of bearings will be 'diagonal' (the force and counter forces are vectors and they are offset. The wheels are acting like levers.
So in my case if bearings 1,2 are in good shape and 3 , 4 are bad.... if I am right that the noise is coming from the left rear wheel.
I think the safer option is replacing both rear wheel bearings.

Best, Martin

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