I have a 2010 Outback 3.6r, 6 cylinder, 38000 mi., excellent condition, new tires.

 

Have been through many diagnostics at dealers. We did, new L front wheel hub, RT is in spec,per dealer. Force balanced tires.

 

Dealer replaced the new Yokohama tires with another Outbacks tires and it solved a lot of the problem. We then put new Continentals on it seemed good for  about a week and the the intermittent vibration is back...as bad as if we had not done anything?

 

Looking for help and answers, before getting rid of car.

Who knows. Bad front strut. Axle installed improperly during wheel bearing install. Wheel bearing installed incorrectly, and or bent hub.

 Ball joint no good. Control arm bushings worn or bad. Maybe even a bent axle shaft. Could also be a bent rim/wheel.

 A tire shop can check that for you, by putting the wheel on a machine to check for straightness in the wheel/rim itself.

 Maybe a bad transmission or motor mount. I would say, systematically eliminate each one of these things as a possibility,

 At what speeds and under what conditions are you getting vibration?

 Going straight, turning, or both?