I have a 96 tracker 4X4 with manual hubs.  When I am going down the road & I keep my wheel straight I get a little bit of a vibration sound from my drivers-side front tire.  However, the steering wheel doesn't really shake or shimmy.

When I move the steering wheel to the left, the vibration noise gets really loud & I can feel a slight vibration in the steering wheel.  It will do this no matter how fast or slow I am going. 

There isn't any weird clicking or popping, so I am assuming that it isn't the cv-shafts.  The tires seem to be wearing properly & I haven't been able to find any irregularities on them.

Any ideas???  I am thinking maybe it's time to repack or replace the wheel bearings.

I'd guess right side wheel bearings - a turn to the left causes a weight transfer to the right, increasing the loading on that side.  I would change both sides though, if one side is worn, chances the other side can't be far behind.

Lift up the front and try to wiggle the tire, usually that gives you an idea if the bearings are going out.  Not sure, but Ive seen some CARS do that and it was the front swaybar endlinks.  I would check those out too.