really wierd vibes

Ok, this is really weird, and it is pissing me off. It is liek nothing i have ever seen posted here, so i thought i'd ask for opinions.

I had a busted front left hub, which i replaced with a used, but working one.
Now, this is what i felt at first, everything was fine, no problem, drove much better than before.

The next day, at about 60-70, i started feeling some shaking. It feels like something is going side to side, once i go above 70, it dissappears.

Yesterday, it got progressively worse, now, if I go over 90, i can litterally feel, what seems like, the front axle moving left to right.

While I was in that range, I looked out my window and unless i am crazy, it looks like the tires shifts about 1/4" left and right when the vibes occur, but then go straght when i slow down to a speed range when i don't have any vibes.

What the hell could it be?
I know one thing that is wrong is that the rod connecting to the tie rods is bent in, but it has been like that for a long time, could it be that?

Could it be that my tires have lost their balance?

Please help.

Check out your track bar ends and mounts. Thats what holds your axle centered left to right under your vehicle.

I will do that, although it was changed for an OEM brand new one 8 months or so ago. COuld it be bad already?
Also, how would i check it? Just try to see if i can move it?

Yeah, I found my problems by leaving it on level ground and having someone move the steering wheel back and forth while I watched, could see it wobble every time it passed center. It may not be that your parts are bad, they could simply be loose.