i have a 1997 sebring convertible jxi with a v6 engine and auto trans. when just sitting it's fine but as you increase speed you can hear a humming noise. it worst between 2-3 grand on the tach. i don't know if it's any worse over 3 b/c i haven't had it reved that high when driving it. sounds like it may be a bearing of some sort. the wheel bearing was bad and had that replaced and now theres this noise. what else could be causing that kind of humming noise? something inside the transmission? any help would be great. thanks.