BT1984

hello, im still having vibration issues with my 2013 zo6/z07 with the brembo carbon brakes and GM will not fix this issue even though the car has been sent to a specialist on brakes steering and suspension and was told that 9/10 it is the brake rotors are out of balance. there is even place on them for the weights to bolt too. it has had the wheel runout checked twice, new tires and tires have been checked and balanced 5 times, rotated twice, air pressures played with, the problem is somewhat intermittent. i need any info and any help i can get on this subject to prove that this is an issue instead of 4 different dealers and gm blowing me off. my car is still under bumper to bumper until September. i live in bfe, ok and the car has been sent to dallas, tx to get someone to repair it. so far no luck. if anyone has any info on a dealer that is up to date on issues on he vibration these cas are experiencing please let me now. it can be sent to anywhere in texas via trailer or if close to dallas can just drive it there. thank you for any feedback.

seamus2154

GM warrantied all 4 of my rotors on my 2011 Zo7. They did every test possible trying to blow me off. Replaced tires, rims, indexing, road force balancing, hub run outs, rotors runout, ect. I had it elevated to a GM regional engineer, who then was in touch w. GM. Bottom line the rotors were out of balance and they wanted to band aid it. I refused. It is a known issue to them. The new rotors are balanced from Brembo. They ordered mine straight from Brembo, not to use old stock which could have same issue. They sent them to GM first who tested them, then sent them to my dealer for install. There are weights on the new ones. Guess what??? Perfect after the new rotors!! Ask the dealer to elevate it to GM and start an open case with them. It gets a GM # then it gets dealt with better.

Did you read the sticky here in the ZR1 section???

They know, you cant give up. I just bought new rotors on Amazon and they are the new ones w/ weights. Good luck

kevakasper

I just went through this on my 09. I had access to a shop who agreed to let me use their equipment to spin my rotors. Both fronts were out of balance. Drivers was an ounce out, passenger was .5. We road force balanced the new Michelin PSSzp and got a perfect balance. I then bolted the rotors to the rim (indexing one hole to the valve stem so I could duplicate the reinstall) . Re balanced the assembly and both were out of balance exactly the same as the rotors alone. The weight required was being called to install the weight at the outer front edge which made sense as that is where the rotor rides. Bottom line was a simple fix, and the car is glass smooth now. I painted the end of one lug, painted a dot on the rotor hat behind the rim, and the valve stem is the index on the wheel. Simple, Easy, quick fix that took all of 10 extra minutes. Why GM never thought to do this is

seamus2154

Indexing the rim/tire to the rotor which is unbalanced, is a fix, but does not address the issue of--the rotor is unbalanced. GM has done this for many guys who accepted it. BUT what about when you get new tires or a flat? Your back to square one. Indexing for me at the time, on a brand new car was no option. Plus I change out between two different sets of rims so it was not going to work with out much effort. Gm knows and so does Brembo which is why the new rotors are balanced. If I was out of warranty or just bought a used Z with this issue I would consider this band aid till I needed new rotors then I would by the new style. This method can get you by.

BT1984

What dealership did you use? Name and location.

BT1984

What shop and where? What type of machine did you use to spin balance them?

kevakasper

Midwest Motors Service in Lake Zurich IL. They had a Hunter electronic spin balancer, we were able to clamp in onto the machine and spin. Then we bolted to the wheel and spun the whole assembly. Glass smooth!

seamus2154

Hendricks Chevrolet. Cary, NC

BT1984

Made a video to show the vibration at different speeds because gm is saying that if it is over the speed limit there isn't much they can do about it. It starts at 65mph and up and is bad at 90mph, even at 80mph it is shaking my hood. How do I upload a video on here?

BT1984

BT1984

The rotors have weights on them for a reason, so they can be balanced, or BC they can become unbalanced?
The weight is circled in red and the bolt hole for the weights are circled in yellow

BT1984

Yeah, I've been reading through all this zr1 vibration section since I bought the car, everything points to the rotors being out of balance. Luckily I don't track the car because if I did this thing would be unstable at high speeds to the point it is dangerous due to the vibration.

BT1984

Nvm, figured it out.

seamus2154

If you are in GM warranty, then call and have it elevated and get a case #. Don't accept indexing as they know its the rotors. They will try a lot of things first but will end up at replacing rotors. If you are out of GM warranty, the above post is how to balance and index the imbalance and does work nicely. The third choice is Amazon for the new style balanced rotors which I just bought. Pricey though. The rotors and pads may last a lifetime on the street but not the track. My old rotors vibrated similar but worse than yours at around 72 MPH-85 MPH if I remember which was my cruising speed on the highway.

mirage2991

Good luck finding those weights, they vary in size too, not all cars have the same....my GM dealer and I tried to figure out where to get them, they made phone calls all the way up the food chain, including service dept an nobody has a part number for them....

For what it is worth I feel the PS2's are a major contribution....AND tire shop balancing with 20lb of road force and call it good when it should be at 10 or less....

I've got 18 track days on my rotors, which were almost vibe free before I started tracking it (after GM replaced the rotors and the front tires) and I can tell you, even with my aftermarket wheels with Nittos or stock wheels with R888, it has never come back....(though seems to come and go when I ran the PS2). you'd think if it was a "rotor issue" it would come back especially when you track the car and actually "wear" the rotor but so far so good....

ClarksZ06

Do u have the Amazon link to the new balanced carbon ceramics?
I found another vendor selling them , they want $1,700 per rotor.

I have a slight vibration at 75. I can live with it but would prefer a fix.
Road force balance on my cup 2's did help some.

Mambo_Vette

http://ACDelco 177-1120 GM Original ..._AFfnxb5YHCJ5Jhttp://ACDelco 177-1120 GM Original ..._AFfnxb5YHCJ5J

I've seen them up to 900. Look for them weekly

kevakasper

Drove mine last weekend on the highway. Zero vibration! Index your wheel and rotor to one stud, makes no difference you just want to be able to put everything back in the same spot each time. I painted the end of one stud, and sharpied a circle on the rotor. I aligned this with the valve stem. Now take your tire and wheel and rotor and have the tire and wheel roadforce balanced. Then have your rotor spun separately to determine how much it is out of balance. Now bolt your rotor and wheel together using M12 x 1.5 bolts and your lug nuts ( I used wheel studs) keeping your index (valve stem) and circled hole together. Put the whole assembly on the balancer, we used a centering cone on both sides. Your wheel will now be out of balance the exact amount that the rotor was. It will call for weight at the extreme out side of the rim ( Face) directly under the rotor. This was a cheap, easy and effective solution to the problem. Brembo and GM are not going to be replacing these. They got past the time frame and we are on our own. It is amazing how smooth this car is now. Different vehicle.

Zeake

How long do these rotors last?

kevakasper

They say you can expect about 20 - 8 hour track days or life time if street driven. It is the heat that will destroy them. Very little actual surface wear, but the carbon will burn out. That is why you cannot measure them to see wear, they must be weighed.