At about 62 MPH my convertible bounces around. I've had new tires put on and all 4 wheels force balanced. Front end alignment is OK. Goodyear says there isn't anything more they can do and they don't think it's a tire. My Ford dealer thinks it's a tire problem. This has been going on back and forth for over a year. There are times when this vibration does NOT happen. Any suggestions that I can take to my dealer?

 

as a quick "check" you could try putting your fronts on the back and backs on the front. see what it does then.

 

rotated by Goodyear. Thanks.

 

My '04 has about 105K miles and one of the front hubs was toast, just an idea, check the ball joints too.

 

What do you mean by bounce around? Like up and down or a wheel speed oscillation. Exactly 62 mph?

Road force or not. A wheel assembly that is out of round but balanced will still shake the car.

The easiest way to diagnois stubborn vibration problems is to swap a set of wheels from another car. Doesn't even have to be the same size. As long as the bolt pattern is the same and the fit without caliper clearance issues. It will narrown down your problem.

 

I tried to get another mustang from the Ford Dealers to swap tires and they declined because I didn't buy the car or the tires from them. Anywhere from 60 -70 the shuddering starts. What's funny is sometimes I can't feel it until I drive in another direction. Wind????? You can see the front of the car shaking up and down and feel it in the steering wheel and the seat. It's not a slight vibration but pretty violent shake. Other then that the steering is true. I turn the car into the Ford dealership Thursday.
Thanks for your response.

 

Could also be worn out front shocks. If the shocks are worn out, the wheel will bounce up/down as you drive down the road. The bouncing gets worse as speed increases.

Might be worth having a buddy fallow you while driving down the highway and see if the wheels are bouncing or not. Good luck...

 

#5 cylinder was missing...new plug installed. The rims were checked for out of round....OK. Both rear u-joints were dry....replaced. Now the complicated stuff. I'm talking about Goodyear Eagle LS tires all maunfactured in June of 09. Before road force balance the front tires were at 42 and 40 LBS. After correction they are at 23 and 21 lbs and have been moved to the rear. The front tires are at 16 lbs. The shuddering vibration is still there. They recommend the tires be replaced. I'm ready to sell....but who would buy it once they felt the vibration. It's like a Catch-22. Ford only does warranty work on tires they sell. The Goodyear dealer doesn't have the equipment to properly service them (they can't road force balance).
Hey, thanks for letting me vent.......

 

You are throwing alot of money at this problem. Stop and figure out if this is a tire, drivetrain or engine problem first.

Get it up to the speed it vibrates. Throw the shifter to neutral and see if it's still vibrating or not.