So you think you are hearing noises coming from your rear end and you think your rear wheel bearings are going out, here is what was making my noises and the story.
I was traveling in North Dakota and a long way from anywhere when I started to hear a hissing / whirring /strange sound from my rear drivers side axle and it would change with speed. I of course thought something was seriously wrong and headed to the only Toyota dealer in 500 miles in Minot, ND. Well I told them what I heard and what I thought and they of course charged me a diagnostic fee to agree with what I thought and replaced my rear wheel bearings over the next 3 days. Well within 200 miles going back to Montana the sound came back and even started getting worse, I was freaking out and couldn't go back east, they didn't fix it! Well I really wanted to get back to Bozeman so I just went for it and made it back at 2AM. I have always done all my work myself but I knew that the bearings have to be pressed on and I didn't have any tools on the road. Well instead of going back to a dealer I took it to a local off road shop in Bozeman and he diagnosed the problem and to say the least the dealer didn't fix the problem and of course I paid for them fixing something that didn't need fixing. Sorry for the long story but be prepared, it might happen to you. It appears that either rust or dirt roads caused the backing place where the rear shoes are mounted at the bottom was pressing on the inside of my rear drums in a grove what appears to be a dirt / mud lip. If you look at the ring attached behind the plate, mine is rusted along the edges and all we can guess is the rust along with dirt and rocks helped press the plate inward ever so slightly, like 1/100 or so of an inch and along with heat caused the slight rubbing With the temp of the rear heating up while driving the plate would flex just enough rub on the inside of the drum dust lip and then stop when cool. Mike ground down the edge and I ground it down a little more to stop the noise and no, my bearings were not going out. I have included some picts of where to look.