steering wheel shimmy and vibration

I recently purchased a 2011 tacoma, double cab with a long bed. I have had steering wheel shimmy and genaral vibration since day one. My truck has been in the shop 6 times, for allignment and wheel balancing. I have dunlop grandtrek at20 tires.after all of this i still have the problem. the mechanic says its the tires, the service manager says he ha "hit a wall" and cannot come up with a solution. Has anyone else had this problem

 

Does it shimmy/shake/etc only when braking or is it always like that? If it's only when braking, it could be related to your brake rotors. Do you know if they have replaced any ball joints? Another possibility is that you have some defective steering shaft bushings (sorry, I can't remember the actual name of those). I also have some Dunlop tires (a/t) and they are really unevenly worn, causing some shaking, but if yours are new, they shouldn't be the culprit.

 

the steering wheel will shimmy and shake at speeds from 60 - 72 mph. it
dosent seem to be road smoothness related, it feels like the tire are out of balance. even though Toyita has balanced and re-balanced them 6 times.
the tech at the dealership thinks its the tires.

 

I have this same issue, and I have had the tires balanced over 10 times, with the same tires your running. I also have a 2011 TRD short bed. From what I gathered is that the Dunlops are junk and some have changed tires to another brand and the problem went away. Some have also changed the entire wheels and tires to something else and the problem went away. I just can't see myself spending that money at this moment. Pretty frustrated as well.