Need help??? Heavy Steering wheel vibration only while braking...

[NastyG]

I have just added the eibach pro-kit, waited a week for the springs to settle and had a new alignment at a lowered suspension specialty shop. I am getting bad steering wheel vibrations only when braking and when slowing down at low speed my tires are making a loud lumpy sound like woo woo woo. Is it my rotors that could be warped or am I running on too low tire pressure? I didnt feel this before the suspension install. The shop told me to run my tires on 35 to 40 psi. I know aggresive tire tread and low profile causes noise. I do not think my wheels are out of balance cause I'm smooth from 0 - 100 mph. Anyone have a clue? Need some help. Thanks

[cyaa]

whats up nasty g the whip looks goodI think you are on the right track with the rotors I mean if it's only doing it when you brake chances are it's the rotors but before you go out and buy new rotors which cost aroud 9 hundred have them checked buy a shop you trust and don't let the dealer tell you the brembo rotors can't be cut because I had mine cut and they still work at almost 30000 miles later cyaaP.S. keep it clean

[infinititech1]

with the tire noise...sounds like your tires are feathered which is very common for the g as they come with negative camber from the factory. the woo woo noise is your tires. so you don't have to worry about that. you need to get the front rotors cut.

the only other possibility would be a wheel bearing...but that would be making a noise pretty much at all speeds.

[NastyG]

Thanks for the help. I assumed it was the rotors but with only 15000 miles I wasnt sure.

Can anyone advise of a good tire with the lowest noise quality? Is there a significance to the tire tread pattern? Like should I look for a long simple tread pattern rather the multiple cross hatch groove?

[NastyG]

I found 3 deep non common grooves in my right rotor. All 3 other rotors are perfectly smooth.. I know these grooves have already made there mark in my pads.. Is there a way to approach this as a defect and have the dealership replace the rotor and pad? There is no reason for this one to be so bad and the others perfect is there?

Thanks for the help...

[infinititech1]

unfortunatly the 06's dont have the brake warranty like the 03-04's did. so that would probably come out of pocket.

[silkysmoothyjud]

Just do your front rotors. Wow, thats a sweet ride...Are you sure the specialty shop didn't "do" your rotors? At 900 bucks, they might have. I dont let nobody touch my ride....

[C-Kwik]

Couple of possibilities. Warped rotors. not a very common problem for newer rotors though. Could possibly be uneven brake bedding where there is more pad material on a certain area of a rotor. If it's minor, it can be cleaned up by turning the rotor as long as it doesn't take the rotor below he minimum thickness. This effect is generally the result of holding the brake pedal down for too long while the rotor is very hot and the car is not moving. In an exteme case, The pad material can imbed carbon into the rotor. And this could be diagnosed as rotor warpage as the carbonized area of the rotor would wear more slowly causing a varying rotor thickness. Turning the rotor in this case may not get you past the carbonized portion of the rotor and uneven wear would occur again.

Another possibility could be a flat spot in a front tire. Though, it would be unlikely, as the G35 has ABS and would make it difficult to create a flat spot.But I did have a car that I flat-spotted a tire on and it had a slight vibration only when braking.

The last thing I can think of right now is a bent wheel. It may not make itself apparent until loaded if the damage to the wheel is minor. I've experienced this myself on a car I ran over a curb at speed with. I suppose a damaged tire sidewall could also produce a similar result as well.

[joe603]

Because the symptoms started after the install, I would have the shop inspect the brakes. They could have missed a bolt when re-installing the calpers...who knows.

I don't think its the tires, it would typically get worse as you increased speed.

If your rotors are warped, you would feel the brake pedal move when you tried to stop...do you have that symptom?

[silkysmoothyjud]

Ive missed a bolt on my caliper before, its a noisy ordeal. It's his front rotors and at 15k, I smell a rat!