Well I found out that the noise my car has been making is the right wheel bearing. The tire and wheel doesn't move at all if shaken up/down or side to side, but if you jack the car up and just run that one wheel man does it sound bad. Anyways, I went to a local garage and asked for an estimate and they said a 90 sentra doesn't have a wheel bearing but is called a hub bearing instead. Is this correct? I don't know much about suspension and stearing systems but would just like to know the correct terminology so I don't get screwed over by some mechanic.