My trans am starts to vibrate at right around 65 mph. I just got new tires today and had them rotated, and it's still doing it. Could it be the U-Joints? It kinda seems like it starts in the front of the car. Any help is appreciated.

 

do you mean you had them balanced? if not, I think you better...

 

Yeah, I meant balanced.

 

Can't someone help?

 

could be a multitude of things. was it vibrating before the new tires? if not, then it is within the tires. if so, then could be tie rods, ball joints, idler arm, shocks, struts, center link, or bushings. would need to get it up in the air and shake things around to find out.

one way to test for u-joints. does happen at a particular rpm? or just at 65mph. get the car to the point where is vibrates. put it in neutral. if the vibration goes away, then it is the u-joints or imbalanced driveshaft. if not, then suspension or tires.