I have a 03 4x4 power stroke.A couple years ago I changed the wheel bearing hubs,changed to the locking hubs and ball joints. now it has a howling noise all the time when moving.the front axle is loose and I dont remember what holds it straight. It only makes this noise when the hubs are unlocked,lockem in and it goes away.Please help me before I blow a gasket.

Thanks Ben

 

could this be from bad needle bearings and if so is there an inner and outer?

 

I would do a tear down and inspect, you should find a bearing or 2 that maybe blue, if blue then there is your answer.