rear roaring noise

Make sure there is nothing rubbing but it sounds like the wheel bearing may be bad. If it is a job you are thinking of doing yourself there is a company that independent auto repair shops "buy" their information from that offer a very reasonable service to do it yourselvers. You can get a one week subrcription or year subscription very cheap. The information is year make and model specific repair procedures, service bulletins, component locations, wiring diagrams ect.... great quality information same as the professionals have ,much better than generic workshop manuals from parts stores, much cheaper than the factory manual try http://bit.ly/mitchell_repair_manuals_online and get an online repair manual subscription.

It could be wheel hub assembly. That's the whole piece where barings are packed. If not that you may wanna have axle checked. Either way not cheap to repair. Good luck!

it could be your center bearing