slight grinding

[joedirt00]

I have a slight grinding sound coming from my front tires, sounds like it is coming from both sides. I recently replaced my wheel bearings, ball joints and my rack and pinon. It is only noticable at about 20-35 mph. Braking doesn't seem to affect it, neither does acceleration. I'm thinking it might be my hubs.
I have a 97 explorer sport 4.0L v6 2wd.

 

[joedirt00]

bumpidy bump

 

[joedirt00]

no ideas anyone? I really don't want to go to a mech. for something small.