help steering wheel shake

[40th_GT]

have an 04 gt with 5000 miles on it and heres the deal. at about 45-55mph or so the steering wheels shakes not too bad but noticable and at low speeds it fine and also at higher speeds. What happened was at around 2500 miles on the clock i was driving one day and some dip**** slammed his brakes for bag in the road and i had to slam my brakes as well and they locked up for about 25-30ft give or take and had wheel turned to the left and ended up puttin flat spots on both front tires. Yes my car doesnt have anti-lok brakes turns out its an option for 04's. Ever since i bought new wheels and tires they are oe concept replica bullit style wheels which are 18x9's all around thinking this would fix the problem and instead of buying 2 new tires for the front went with aftermarket so i never got to see how the oem setup would have been with new tires. the tires i have now are 245-40-18's any help would be appreciated.

 

[back_in_black]

Our front rotors get heated up and warp, that is wht a lot of people replace them with bigger cross drilled ones, you feel the warped calipers as steering wheel shake.

 

[codyGT]

Well does it get worse when you lightly step on the brakes? If a rotor is warped bad enought shake the steering system when the brakes are unapplied then it should get orse when braking.

Otherwise who ever balanced your wheels did it wrong.

 

[twogts4us]

Sounds like an alignment or wheel balance issue. And a 25-30 foot lockup will not flatspot tires.

 

[Marine One]

I'd check the wheel balance first. See if you can find a shop with a Hunter 9700 machine. It can perform "road force balancing" which I think is substantially more accurate than standard spin balancing. It places the wheel & tire under a simulated load to replicate what they actually experience on the car. I've had a lot of challenges with balancing on my Cobra's front tires (same basic problems you're experiencing), and the Hunter 9700 did the trick. One other thing: If you can find a shop that will let you into their shop while working on your car, tell the mech that you think you may have flat spots on your tires. He can run them up on the spin machine and you and he can inspect for them as the tire rotates on the machine. The Hunter 9700 will also give you a numerical index of the trueness of each tire.
I'm more inclined to believe that your panic stop did shave enough rubber to put flat spots in the tires or alter them enough to affect their balance. I find it hard to believe that one panic stop would warp your rotors, especially with such low mileage on your car.