daves4

Smooth until about 75ish, and then gas pedal and steering wheel bouncing a slight bit under the hand and foot. Passenger can even feel it, smooths out at around 85ish. Not tires, since just switched to snows, and same thing.

ideas?

Distinct

Could also be wheel balancing. Are the wheels clean?

Daryl@Tantrumwerks

Get the tires re-balanced

BluDemon

My car ran great up to 65 and then went to shaking and 80 I actually had to squeeze the steering wheel to keep it going forward.

daves4

Yea? Even though both tires seems to do the same thing?

daves4

no alignment? just wheel balancing?

BluDemon

I bought my tires from sears and they tried to balance them 4 times. All 4 times they left me with wheel virbration. I finally went to Goodyear/Gemini and the tech took his time to rebalance the tires.

When he checked them with the wheel weights on he was shocked to see them out of balance so much. Sears put weights all over them chasing the balance. When the Goodyear guys was done with them there was only one to two weights on each wheel and they are so smooth again.

When I first told the Goodyear guy my story he really though a tie rod or suspension component bit the dust but everything was tight.

But I would check there also for any problems.

Hibiscus Red S4

Same thing, from about 78-83 mph

BoneStockS4

Did you change rims with the tires? Could be a bent rim(s)

s4_flyer

...you have. Most prevalent problems or issues with front end shimmy are as already noted by esteemed AW'ers... bent wheel(s), balance, tie rod ends, warped rotors, bushings, flat spotted tire...etc...

Rotors have been a frequent culprit...

Good luck.