I have a shimmy in my front end when I apply the brakes. I have had the rotors turned, tires rotated. I have no idea what is causing this. Can anyone help?

 

If its only when you apply the brakes I would think warped rotor.

Does this involve stearing wheel shake or do you feel it in your butt?

Do you feel any pulsing in the brake pedal when you depress the brakes?

Give us as many detailed symptoms and I am sure we can help.

 

Toyota trucks are notorious for front end shimmy, primarily from warped rotors. The OEM rotors are sub-par, IMO, and can be replaced cheaply with aftermarket rotors, such as Brembo's. Do a forum search on this topic. There is a ton of info.