Could this be a bad wheel bearing
3 Answers
Speed when it occurs can be needed to be definite. you can safely jack it up and listen to it. be sure wheels are stopped before selecting park, issues with other parts can sometimes confuse sound to the ear of the driver, so isolate it. do inspections and prechecks for causes as you decide what to diasssemble. axle bearings, because of their diameter can rumble at higher speeds than tapered roller bearings for the front. but damaged bearings may happen at lower speeds. I had a guy ask me a few weeks ago to listen to a bearing and we found a speedo cable issue. another was a driveshaft support.
A definite "roaring" accompanied by a loss of power on accelleration can be a froze up fanclutch. that is noticed leaving a stop and throughout the speeding up process through first gear and continue beyond.