4 Wheel Drive/SUVs: 2000 Suburban, wheel alignment, shock absorber

Question
Hello, I have a 2000 Suburban 1500 4x4. Recently the vehicle has started to pull to the right when driving. It also seems unstable when making left turns, especially on the freeway. When changing into a left lane, it seems the truck sways ( from front and rear) and I have to keep both hands on the steering wheel to try to make a smooth lane change. I have had the vehicle at two different alignment shops and it still drives the same. One shop replaced both my front tires with new ones and it still performed the same, now they rotated the new tires to the back, still no solution.  The vehicle has in the past worn out the front tires in the inner most section of where the pavement hits the tire.  

Answer
Ran,

I hate to say it, but it sounds like the alignment shops are not doing their job.  Anytime you get pulling like you are describing, it can be several things.  The first, is uneven tire pressure.  If that's ok, then you need to start looking at wheel alignment, dragging brakes, or a problem with your power steering.

If they are having a hard time aligning the front end, you may have worn out bushings, or ball joints in your front end.  To a lesser degree, due to the weight of the large vehicle, it could be a shock absorber problem.  

I would suggest that you go back to the shops that did the work, and have them go for a ride with you.  Make sure that you drive it with them as passenger, so that you can confirm your problem.  Then if they wish, let them drive it for a good feel of the problem.

Carl