2008 Dodge Charger

Steering problem
2008 Dodge Charger V8 Two Wheel Drive Automatic 12000 miles

wheel steering vibration. Started 8 months ago. Back and forth to dealer ship, no luck, I am giving up.
vibtation started suddenly, no symptoms. I had aftermarket wheels at the time. They told me the after market wheels is the problem, they suppose went out of shape. So I replaced them with original 20" dodge rims. Problem still exist, exactly the same at 60 miles hr as always never before 60 miles hr.
so they told me its the tires so I replaced them with new ones, and after balancing again, still exactly the same at 60 miles hr and up. They checked all suspension components, they said it was fine. The only thing they replaced was tie rod had little play in it on passenger side, but that did not fix sever steering wheels vibration. Balanced the wheels over 20 times at different shops, no improvement.
the only thing I noticed, that car will drift slowley to the right at high speeds 40 and over always to the right, never to left. Offcourse they aligned it 2 times, still drifted to the right, I even inflated passenger tire to 50psi and deflated the other to 25psi and still drifted to right, my steering wheels is always straight. Which is aligned. No noises or clunks from suspension, very smooth on hard roads and bumps. Please help. Very very bad steering play.
April 3, 2010.

Ok. Sir. Last thing I did, replaced the tension struts and road force balance tires, which I think they did a great job, although, they said it was difficult to balance these tires on road force were they had to match the rim with tires. Anyway. Test drove and my complaint about shimmying at 60mph and up had transferred into pulsating (tapping) in steering wheel without a shimmy. The higher the speed the higher is the pulsating, almost into a shimmy. It is an improvement but still cant explain the bad pulse, it feels as if the steering is vibrating but its not. Its tapping on the steering wheel, which was already there before, but transferred into a shimmy too soon.
So now I have almost no shimmy but left with bad tapping on steering wheel at all speeds after 60mph.
The only thing I noticed recently when they had the car up without the wheels, is the rotors, you can move the rotors in and out of the studs easily by hand, is that normal? Have not changed the steering rack yet because thats the most expensive part, so iam leaving that for last. What do you think? Thanks

May 10, 2010.