2011 NISSAN PATHFINDER Steering Problems

MY VEHICLE IS TO THE POINT I AM AFRAID TO DRIVE IT. SOMETHING IN STEERING MECHANISM, IDK BUT WHEN DRIVING ANY DIFFERENTIAL IN THE ROAD THE VEHICLE IS ALL OVER THE ROAD.. I AM A SINGLE PERSON WITH GRANDCHILDREN AND THIS IS NOT SAFE. IT IS SO BAD IT WALKS INTO ANOTHER LANE OF TRAFFIC. THIS STARTED A FEW WEEKS AGO AND I TOOK TO A LOCAL MECHANIC AND HE COULD NOT FIND A PROBLEM.

THE VEHICLE HANDLES SMOOTHLY ON A SMOOTH SURFACE, BUT WHEN I HIT A SMALL BUMP IN THE ROAD, THE STEERING WHEEL SHIMMIES GIVING YOU THE FEELING THAT YOU MIGHT LOSE CONTROL. BIG BUMPS IN THE ROAD AT HIGHER SPEEDS (60-70 MPH) ARE DECIDEDLY UNCOMFORTABLE. I TOOK THE VEHICLE TO A NISSAN DEALER AND A VERY KNOWLEDGEABLE TECNICIAN DROVE THE VEHICLE WITH ME BUT COULD FIND NO STRUCTURAL PROBLEM. THE DEALER I PURCHASED THE VEHICLE FROM MACHINE BALANCED AND ALIGNED THE VEHICLE BUT THE BEHAVIOR OF THE VEHICLE REMAINS THE SAME. THE MAINTENANCE MANAGER WENT ON LINE IN THE INTERNET TO SEARCH FOR ANY COMMON COMPLAINTS AND CONCLUDED THAT WHAT I FEEL AND SEE IS THE RESULT OF THE WAY THE VEHICLE FRAME IS MADE WHICH CAUSES THE MOVEMENT WHEN YOU HIT A BUMP OR DIVOT IN THE ROAD. I HAVE TO HOLD ONTO THE WHEEL WHEN I HIT A BUMP,...