I rotated my tires from front to back on the same side and now I get a vibration, any ideas. Do I need to take it in to be balanced?

 

How long/many miles has it been since you rotated your tires. Are you getting vibrations while braking or during regular driving? Sounds like an uneven wear. Maybe too much camber? But then again it just probably needs to be balanced. Try checking tire air pressure.

 

I went 18K between rotations, I was also thinking wear, becuase it gets worse as I drive faster. I need to buy some new tires anyway for winter

 

This thread should be in the Wheels and Tires or Tech sections. Don't mean to be a hard nose but it's just in the wrong place.
PS You should have your balance checked. You want to make sure you don't have a bent wheel.