Vibration on Newly Purchased G8 GT

[FCNFST]

Yesterday I headed across Georgia to pick up my new G8 (picture below). During the test drive, I noticed a nasty vibration in the steering wheel from 55-65mph. Owner said he thought it was a missing balance weight, as I voiced my concern of a possible bent wheel. I immediately drove the car to the nearest tire shop to have all four wheels balanced. The vibration is no longer felt from 55-65, however, there is still a vibration. This time in the seat (possible rear tires or driveline?) from about 80-90mph. I'm not sure if this vibration was there before, as I never exceeded 70mph prior to the balancing. Hopefully, the kid at the tire shop didn't balance one of the rear tires correctly, and that's all I have to worry about. Any ideas?

[joemomma]

Read this post... Good place to start.

http://www.grrrr8.net/showthread.php?t=13525

[GXPaycheck]

Try a road force balance.

[roman1978]

I had a difrenciral replaced and after that I started to have vibration people told me it was from driveshaft

[cynic783]

the cars are sensitive to balance of wheel assembly. some tires just wont allow you to balance out very well. you can try a road force or a new set of tires.

[-Ray-]

I would focus on the drive shaft. If you can get under the car, check to see if it looks like it was removed. The driveshaft is sensitive to rotational positioning. You can remove the bolts, rotate it 60 degrees, and test. For cars that are under factory, the Driveshaft Shop has been providing balanced prop shafts for the dealerships. They haven't done it publicly yet, as far as I know.

[travis gore]

I agree with Ray check the driveshaft

[GXPaycheck]

Trans mount? There is a service bulletin for this.

[FCNFST]

Read this post... Good place to start.

http://www.grrrr8.net/showthread.php?t=13525

Yes, very informative. Thank you

Try a road force balance.

Never knew these existed. I've now watched a couple operational tutorials in order to be able to make sure whoever is performing my balancing, performs it correctly.

I had a difrenciral replaced and after that I started to have vibration people told me it was from driveshaft

Please, no!

the cars are sensitive to balance of wheel assembly. some tires just wont allow you to balance out very well. you can try a road force or a new set of tires.

The rear tires are worn, so I will order those tomorrow. As soon as they get in, they will be balanced via the Road Force, as well as the current fronts.

I would focus on the drive shaft. If you can get under the car, check to see if it looks like it was removed. The driveshaft is sensitive to rotational positioning. You can remove the bolts, rotate it 60 degrees, and test. For cars that are under factory, the Driveshaft Shop has been providing balanced prop shafts for the dealerships. They haven't done it publicly yet, as far as I know.

What red flags would indicate it has been removed? Rust knocked off bolts? Please elaborate on this rotational test. I assume I wouldn't have a chance in receiving one of those balanced prop shafts would I?

I agree with Ray check the driveshaft

I will, but my fingers are crossed that the vibration is just due to the wheels/tires!

[xruling]

Just went through this with my car. Had road forced balanced wheels, but still had the vibration. Long story short, I got some centering rings from Discount Tire and no more vibration, at least below 90mph. I have aftermarket wheels. Don't know if the Camaro wheels that you appear to have match the hub ring or not, but if not, spend the $15 for the centering rings. Concerning the drive shaft: If the car had the oil weep recall done, then the crank shaft was probably removed when the transmission was pulled. If the tech did not mark its positioning, it could have been reinstalled in something other than the factory balanced position. That would be the last vibration cause that I would pursue. I believe that you will feel the drives shaft more in your butt than in the steering wheel.