Na boss, you know wheels related sounds are always tested on the road with an idle engine. i mean i speed up and then put the car in neutral (ideally on a neat road with a slope, there are plenty in islamabad...) and then listen to this ghoon ghoon. thanks for your quick reply anyway, boss.
it's frustrating because i believe there's no other rotating part in the rear axle other than the hubs, and i've changed those. so what else could it be?!?!?! may be it's a 4WD