need help with noise

so for a while my car has been making a strange noise. it sounds kinda like a roaring tire sound, or like a humming whining noise. its coming from the rear of the car and i cant quiet figure out what it may be. can anyone give me any suggestions to what it may be? thanks in advance for everyones help
 
Get out on the road and up to the speed where it's the loudest. Then zig zag a little a few times, just enough to trasfer weight from one side to the other. See if it gets louder when you go to the left or the right.

If it gets louder when you go one way than it does the other way then it's probably an outer axle bearing.

If there's no change at all in the sound then it's probably the pinion bearing or a carrier bearing.
 
well guys i just dont have the time to look at it and try to figure out whats wrong with it. and i need to get it fixed soon so im just gonna drop it by my mechanics shop later today and get him to look at it and see what it is. and see how much its gonna cost to fix it. hopefully its just a bearing and wont be expensive to fix. ill let everyone know what was wrong with it. thanks again for everyones help.
 
well guys i finally got my car back from the shop on wednesday and now theres no more squeak. Apparently i had 4 bearings go bad in the tranny which was causing this noise, well thats all fixed and had a brand new clutch installed when they were in there. only thing that sucked was they had to take my headers off to get the tranny out, which meant more labor which equals more money. but it was all worth it in the long run.