Hi Everyone... The steering wheel shakes around 60-70 mph when driving the car. Could it be that a wheel is out of balance? The alignment seems to be fine the car only has 7K miles on it and has been trouble free since I have acquired it as a CPO. Finally, since the car is still under warranty, would the dealer charge me anything to diagnose the issue?

Thanks in advance for the responses...

 

Out of balance would be my guess.

 

It's either wheel balance, tire pressure, or alignment. I don't know why you assume that your alignment is fine simply because the car has only 7k miles. Alignment can be wrong off the boat, or after hitting one nasty pothole.

However, a shimmy at high-speeds is typically caused by at least one wheel being out of balance. Best correction involves spinning the entire wheel and tire assembly while on the car at 120mph. Any top wheel shop should be able to do this- if they can't do it on-car at 120mph, move on. The way they do this is they raise the car about 8 inches off the ground, and have a bench that the tech sits on with a wheel that will at 90 degrees spin the car's wheel at up to 120mph. They observe, and use chalk to mark spots out of round, and add weights to the wheel appropriately as counterbalance.

But by and large, these issues are your own, as they are not vehicle issues, they are repair issues that you are responsible for. If you have a hi-end wheel shop near you, you could go there, and the most it should cost is $200 for an alignment and hi-speed on-car (to 120mph) balance. Check out
CATTMAN

 

Thanks for the response... I assumed that the alignment is fine because the car doesn't pull or drift away in a straight line.

What is a high-speed-on car balance? Never heard this terminology before.

 

1) Could be as simple as a wheel weight falling off after washing the car.

2) If the wheels are re balanced and the problem persists the next step might be to see if a tire is out of round.

 

Most shops use a Hunter Road Force 9700 when mounting new tires to new wheels, and that's fine. However, a 997 has such tight feel, that that is not enough. The Hunter 9700 is a machine upon which a wheel and tire combination are mounted, and spun. Observing this, techs can add weights, etc. to counteract off-balance nuances.

However, this can't hold a candle to performing a similar test while the wheel and tire combo is mounted to the actual car. This test involves an ancilliary tire at 90 degrees mounted to a tech bench used to spin the on-car wheel/ tire assemble at up to 120+ mph, while the tech sits there watching. Here, the tech can see, while the wheel and tire assembly is on the car, where any unbalanced sections may exist, and add weights to the opposite side, to counter them.

The off-car balance cannot accomplish the same level of perfection. If you like this, hit the gold metal "star" at the top of my thread to give me kudos for taking the time to help you.
CATTMAN

 

Cattman - Thanks for the detailed explanation. I will look for a shop that can perform this type of test for balancing my wheels.

 

Not sure what your driving conditions have been like lately...but first thing I check when I get a vibration like that is are my wheels clean. A chunk of mud is basically a wheel weight working against your balance. Clean outside and inside of rim and see if that has helped.

 

Agree with above - unlikely allignment and either balance (most likely), out of round tire and lastly bent rim. Good luck.

 

it depends, come to dealer and make a claim, if issue is repeatable they will fix it.

if issue will be related to any wearable parts like brake pads or rotors - you may have to pay for them. on my lexus I had very bad steering vibration that was caused by lazy piston in left brake caliper that stopped retracting completely so it took a lot of meat from brake rotor and it was causing a lot of shaking.

 

Worn rear tires can also do that, specially if the vibration is at high speeds and also make your seats shake. But, with only 7k miles, I don't know if you're there yet. At least for me rear tires last anywhere from 12k to 15k miles.