Ball Joints

[Elephanthead]

I am on tight budget, and I am repairing this truck 67 one ton, to just be used occasionally, anyway I either have the worst balanced tires ever, I already am planning on replacing them, or I have something bad on the suspension, anyway the tie rod ends seem good, there is little play, so I am suspecting ball joints are bad, what are the chances I can get by just changing the lower ball joint and not dealing with the uppers? I am already over budget on this thing, big shocker I know. Can I get the lower control arm to drop and leave the spindle attached to the upper? That would save me some work. I plan on borrowing a ball joint press from auto junk zone to get the lower out. The lowers are just pressed in correct? Thanks for any input. The symptom is severe shaking at about 20 mph. The truck visibly rocks back and forth. I am going to change the tires and see if it improves, I am also assuming the shocks are useless.