I bought a set of Cray Hawks three weeks ago from a large national tire chain and had them mounted with new Michelins (go flats) at the same time. I immediately noticed a rhythmic vibration coming from the back...shook the whole car. They orderd a new Cray wheel saying the run-out was out of spec on one of the rears. New wheel was installed a week later...the rhythmic vibration was gone, but a pronounced shake was still evident - coming from the chassis - not the front. The steering wheel never had any shake at all. I ordered all NEW Michelins from the same dealer and he put them on today. Drove the car to find that the shake was still there, seemingly unchanged from the first set of Michelins. So here I am - three weeks later with untold hours invested in all this tire changing (I have personally invested 8 hours or more at the tire dealership in all this changing around). So I am faced with: living with the shaking....backing the whole deal out....or picking another type of wheel altogether. I still have the original wheels and tires that came with my C7...only the pressure sensors are now in the new wheels. What would you do? I love the look of these wheels, but the aggravation factor is off the charts. Not wanting to go back to my plain, painted wheels that came on this 1Lt if I can avoid it! HELP! Suggestions?

 

You might want to try what I did on my last c6 on a set of aftermarket cup wheels bought off ebay

What I did was mark the stud closest to the valve stem then move the wheel 2 studs forward, about 1/2 way, then see if the vibration has improved.

Mine improved to the point where it was barely noticeable.

Other than that you can try someone different for balancing, the wheels that were suppose to be balanced by the first place were not, they had to rebalance my rears the fronts checked out fine.

 

Were your wheels/tires road force balanced and indexed for the least amount of weight and lowest road force #??

I have had several sets of TSW wheels. With the right balance job, they all have been perfect.

Over the years I have probably owned 25 + sets of aftermarket wheels.

I have even had issues with sets mounted and balanced by TireRack, (though only one time).

I currently have 4 vehicles with Pilot Super Sports ( counting my new Vette). 2 G8 GT's and our EB Flex. The Flex is on it's second set. I have never had any balance issues with any of these, and I have a couple that didn't take ANY weights. I would check the wheels again, and perhaps go to a different shop to attempt a re-balance.

 

Do those wheels use hub concentric rings? Are they all installed? Are they the right size?

 

The wheels and tires were road force balanced each time, and Cray makes a BIG point to tell you they are all hub-centric wheels developed and manufactured SPECIFICALLY for Corvette fitment.

 

Was the Road Force # 10 or less?

What did you do with your original wheels?

Some years ago, I purchased a new Denali XL with custom wheels installed. Before I picked it up, the dealer switched out the custom wheels that were on it when I drove it, for another set they had that I liked better. The GM dealer had a Road Force balancing machine, but the person who had originally mounted/balanced the wheels, obviously didn't know how to run it. Car shook just like you describe. I took it back and he tried again, only things were worse. Then he added balancing power, like the big trucks use. WORSE! Finally I took it to another local shop which cleaned everything up, balanced the wheels on a regular machine and it turned out perfect. WHY??? Because the person doing the balancing knew how to balance tires!
I ran those tires over 60K (20" Goodyear Eagle GT's) and replaced them with Bridgestones. Never had any issues again.

That's why I would take it elsewhere to have them check the balance, unless you are positive the issue isn't balance, but is the wheels.

 

Good advice from Ecobrick, both posts. See Hunter's website GSP9700.com to find another shop in your area with a 9700 road force balancer and a tech with the patience to get the numbers right. My 9.5"/11" Cray Brickyards with 265/305 Michelin PSS are perfectly smooth, no vibration at any speed.


.

 

well I have to ask the question.....but seeing as how the original rhythmic vibration was gone, but a pronounced shake was still evident......have you gone back to your original OEM wheels/tires to see if the shake is still there? its possible that the original problem damaged something or put something on the back out of alignment.

Its a worth a shot.....fore if you put the OEM wheels/tires back on and everything is RIGHT....then you KNOW for a fact its your new aftermarket wheels.

 

Also... Can you feel where the shake is coming from. Often it's just one wheel. If so, move that wheel/tire to the other side and see if the shake goes with the wheel.

It is really easy for custom wheels to get damaged, however slightly, in shipment. I had aa Beyern Multi (TSW) that came bent. Very easy to see if you roll your wheels (without tires) on a clean flat floor.

Good Luck!

 

It's small, and may have no effect. I also don't know if C7 wheel/brake assemblies are made with these but take a look at Post #8 (BEZ06), "tinnerman nuts."

https://www.corvetteforum.com/forums...vibration.html

 

It has been my understanding that the C6 and I assume C7 Corvette wheels are not "hub" centric and that they are in fact lug centric.

Wheels that use conical lug nuts are lug-centric...they really can't be anything else since the cones locate the wheel.

Hello,

I see a lot of back and forth on this question. Just want to clear things up. They are not hub centric. The wheels are centered on the stud and are lug centric.

A hub centric wheel is centered upon installation by the machine fit over the hub, hence the term, the OEM wheels on the ‘Vette are lug-centric, meaning that they are centered by the lugs making it critical that a proper torque sequence, on jack stands, is followed. Not properly following the torque procedure will result in an off center wheel and a vibration concern. Hope this helps.

Geoff Allen
Chevrolet Customer Service

 

I have the same problem.make sure that you have 19x11on the rear.if not check to see if they put spacers on the rear.ive tried everything but still have the problem.they tell me that cray have stopped making the hawks,so who knows whats going on.good luck...