I have an occasional grinding coming from somewhere close to my front driver's side wheel. It is a 4wd truck. I've not used my 4wd in the past couple weeks so it does it in 2wd. It had new bearings about 6 months ago. It doesn't do it at a certain speed or when I hit the brakes, it's just random. It does it for a few min sometimes, other times just for a few seconds but it's a pretty rough sounding grinding or rubbing noise. Any ideas? Bushings? U joints? Thanks