I have a 95' Pathfinder SE 4WD w/automatic trans. Since I bought it last summer there has been a whining noise that increases with speed coming from somewhere in the drivetrain that has been getting worse. The sound seems to be coming from the rear but it is hard to tell. The tires are all new (noise was there before and after I put them on). I have changed the rear diff fluid, transfer case fluid, and auto trans fluid, all looked clean with no metal shaving but the noise is still there. The autolock hubs do disengage so I know it is not stuck in 4WD. I inspected the outer front bearings when rebuilding the hubs and they both look fine. Recently I noticed that the noise gets twice as loud when loading the drivers side (like when turning to the left on an entrance ramp, so I suspected it may have been the drivers side rear wheel bearing. I brought it to my normally knowledgeable mechanic and they agreed that was probably the cause, but $250 later the noise is still there! What else can I check? I really don't want my pathy to leave me stranded somewhere. Any ideas would be helpful.