I suspect I have worn rear bearings but I did a temporary fix on mine this weekend that has made them quiet again.
There was some play (3mm tops) in the wheels. The instructions are that the washer behind the retaining nut should have a minimal amount of play in it. That is about where mine were. So I got a spanner on the nuts IN LINE with the stub axle (at 90° to the disc), grabbed the head and did them up hand tight. I am guessing this was about 2-3 Nm of torque on the nuts - no more.
The rear bearings are taper bearings which should run without preload. I did put some preload in but compared to the weight of the car this was nothing.
(Even so, new bearings are on the list... As are rear disks - I will do the lot together as it saves the pain of pressing the old shells out of old rusty disks to get the new ones in).