2004 Nissan Maxima

Hi my name is Rolando. I own a 04 Maxima. Since july my car has been shaking from 40 to 70 miles an hour. I took to a local shop and was told that my tires were cupped. I replace the front struts the rear shocks and put on four new goodyear. Problem still there tires were balance three times at place of purchase. Replace the good year with continentals and balance. Problem still there. I took the car to another local place and balance them again had them check for everything that could be wrong they found that one of the inner tie rod has a little play in it. The problem is still there, can that little play cause the shaking the shop says no. PLEASE help me this is only sucking me dry.