Any component in that front end could be your problem, or a combination of more than one of them. Start by jacking up the front end and grabbing the wheels and shaking them up and down and back and forth. You can also put the tires firmly against a curb so they don't move and then turn the steering wheel back and forth to see if something is loose or worn out.

I assume this is a straight axle front end? If so, you want to look at the kingpins for play, the tie rod ends, wheel bearing adjustment and condition. Have you had it on an alignment rack? Steering box could be worn or shocks could be bad also.

So many places to look, you just have to do process of elimination.

Don