Bushings or Bearings

For the last month I have been hearing a grinding noise coming from the left front of the truck. There is no vibration in the pedals or steering wheel, but it does come out at higher speeds, braking and turning right at slower speeds. It also comes out at slower speeds but not as consistently as at freeway speeds. The brakes have been inspected and are fine. I recently had the tires replaced and the Big-O tires mechanic didn’t hear the noise, but told me the bushings were bad and needed to be replaced. He must have felt some front end sway; I don’t feel it, but probably wouldn’t know the difference anyway. I have 2 questions: 1. Are these symptoms more likley to reflect bad bushings, bad bearings or both? 2. If not the bearings or bushings, what else could this be? thanks, Antonio

2002 Toyota Tacoma (4x4, V6, 5 spd) 90k miles.