wickerpete

Hello. Looking for help from the collective wisdom of the forum. New owner from Wisconsin of a 2012 GS with 16,000 miles that I bought last summer with 9000 miles on it. When I took it out this spring after sitting for the winter I notice a shimmy in the car which seems to be coming from the front end. It’s pretty subtle and I really don’t remember it last summer but didn’t put many miles on it and was still getting to know the car so it might have been there. I can feel it between 50 and 55 and then it seems to go away until about 70. Then between 70 and 85 I can feel it in the steering wheel. Its not there constantly but comes and goes quickly, there for a second and then gone for half a second to return again for a second and repeats in a rhythmic fashion. I was told I had a bad rim so replaced it. No better. I thought maybe I had a bad tire so I put new tires on the car but the problem continues and isn’t any better with the new tires. I’ve had the tires rebalanced and no improvement. There is nothing obviously loose in the front end that I can see although I am no mechanic. Planning on going to the Black hills rally next week and would really like to go 80 😊. Hate the thought of bringing it to the dealer.
Any thoughts on this issue would be appreciated.

Oh Boy

My first thought would have been flat spots from sitting but you said you put new tires. Did you have them roadforce balanced? And if you did have them roadforced what was your roadforce numbers?

GMJim

If you've replaced the tires and the wheels aren't bent and have a correct balance the only thing left to do is an alignment. Though it's possible to get a bad new tire it's highly unlikely. What did the tire wear look like on the old tires?

saplumr

wickerpete

saplumr

wickerpete

Oh Boy

Those are not good numbers for a Corvette. Should be under 10 preferably around 5. Were the rims match mounted to the tires? Yes it is a tire or wheel problem, you just need a competent tire guy who knows how to use the roadforce machine. And by the way not being able to do the rears because they are too wide is utter nonsense! That should have been your first clue the guy does not know how to operate the Hunter machine. BTW when you put the wheels back on the car did you torque them to 100 ft lbs? Another must on a Corvette.

saplumr

wickerpete

Oh Boy

He said he wasn't sure if he had the problem last year before he put it away for the winter. Then having it laid up all winter his tires could have flat spotted and when he put new tires on now the tech could have balanced them wrong so nothing is resolved. I still am betting with the proper tire guy on the Hunter machine he will have found a bad or unbalanced tire or bad rim.

Oh Boy

You need a new tire guy who is familiar with the proper art of using a Hunter roadforce machine!

saplumr

wickerpete

wickerpete

Thanks for all your help guys. I took your advice and googled Hunter road force balancer elite in my area and went to discount tire. Talked to the guy at length and he seem to know what he was talking about. Told him I needed the tires balanced to 10 or less and he completely understood. When he was done the numbers were nine in the front and 10 in the rears. He said he had to add weight to every wheel and had to add a quarter pound to one of them. It seem to do the trick. At 80 to 85 it now runs pretty smooth. I guess not all tire installers are created equal. Thanks to the great advice from forum members.

hrt vlv

If you have eliminated tire and wheel problem, you may have a caliper hanging up. use an IR thermometer and check rotors after run.

wickerpete

RACE U

For what its worth, i had the same thing happen on my c7 z06 earlier this year. New wheels and new tires acted identical to what you are experiencing Took a different shop that force balanced all four. Problem gone. Good Luck.

wickerpete

owc6

Just curious, but what tires are on this car?