shake in front end at highway speeds

[HogTech]

Re: shake in front end at highway speeds

Key questions: where does it shake (steering wheel or seat of your pants) and when does it shake (applying brakes, certain speeds, etc). Shaking at certain speeds could just as easily be from bad bearings or even faulty suspension. I've had both in my experience.

With my 6, I had the rear bearing replaced (my fault, slammed into curb while drifting) and the rotors machined at 8k- both were covered under warranty.

[ragingfish]

Re: shake in front end at highway speeds

Pretty sure my rotors are warped...i shake like an earthquake slowing from 70 to 25 getting off the highways...gonna have to deal with it for at least a year before I can even think about getting new ones...

[HogTech]

Re: shake in front end at highway speeds

Just get em machined man - no need for new rotors

[ragingfish]

Re: shake in front end at highway speeds

Just get em machined man - no need for new rotors

Been done twice already. Costs too much.

[HogTech]

Re: shake in front end at highway speeds

Twice?? Holy dam - that's terrible. Didn't realize...

[Meehdabeautiful]

Re: shake in front end at highway speeds

my car is doing this too. Ive already had the rotor machined down when i first picked the car up.(40K Kms ago) SO i think its time for new ones for me.

[ragingfish]

Re: shake in front end at highway speeds

Twice?? Holy dam - that's terrible. Didn't realize...

Yeah.

Once before the new pads, once since they've been put on. I didn't have the $$$ at the time so I just went with ACD pads again. So once these pads are shot (given the longevity of my last batch, should only be another 15k or so) will go with aftermarket pads/rotors.

[diesavagenation]

Re: shake in front end at highway speeds

I get this vibration while stopping from high speeds too. My car also seems to vibrate while i am driving. It was making a sound like something was rattling around above 50 randomly but they replaced a tierod and the sound occurs way less now. But I still notice it when going over bumps. It def sounds like its coming from the suspension or steering. I had the steering clunk issue. They lubricated it and it went away but its starting to come back. I wonder if the two are related? All i know is my G6 used to drive smooth and now its rougher than my old ford tempo with 190,000 miles on it.

[redsun_ty]

Re: shake in front end at highway speeds

This is annoying because this is my second rotors and it got machined at around 35000KM but most likely I won't go back to the dealership and probably looking for after market parts.

[candypaint]

Re: shake in front end at highway speeds

I notice a slight vibration when I'm going over 55mph down by feet. I let go of the steering wheel to test the vibration and the steering wheel shakes a little, but not harshly. Then when I'm slowing down applying the brakes, a slight vibration, but again not like a seizure. I definitely believe my brakes are going. I bought the car used at 30k, and now I'm nearing 40k believing my brakes were never changed.

To the experts, does this seem like a brake issue?

[ahuhn]

Re: shake in front end at highway speeds

I notice a slight vibration when I'm going over 55mph down by feet. I let go of the steering wheel to test the vibration and the steering wheel shakes a little, but not harshly. Then when I'm slowing down applying the brakes, a slight vibration, but again not like a seizure. I definitely believe my brakes are going. I bought the car used at 30k, and now I'm nearing 40k believing my brakes were never changed.

To the experts, does this seem like a brake issue?

possibly slight warpage
tires probly slightly out of balence as well

[candypaint]

Re: shake in front end at highway speeds

Tires were just balanced about two months ago. Brand new wheels and brand new tires. I'm going to play with my lug nuts tomorrow and see if they need tightened a little. My torque wrench probably slipped a little when I was tightening everything.

[ragingfish]

Re: shake in front end at highway speeds

We got us some 6's that seem to shimmy and shake more than the love shack!

[GT-R]

Re: shake in front end at highway speeds

I posted this along time ago, but it probably needs to be posted again.

Warped rotors are caused primarily because the rotors are not capable of handling the heat created during hard stops. The G6 is for all practical purposes a heavy car, weighing in at 3500 lbs. plus. Rotor overall size and thickness on the G6 is obviously not up to the task.

Things you can do to help avoid warped rotors.

1. When having to brake hard, and then coming to a complete stop, avoid holding the brakes. This causes the heat to be concentrated and retained and where the pads are holding the rotors. This concentrated heat in just one area of the rotor causes most of the problem.

Once you come to a complete stop, put the car in neutral, and remove your foot from the brakes. If you're on unlevel ground and the car begins to move, use the parking brake to hold the car.

2. Going to a dimpled and slotted rotor, will help evacuate the super hot gases that are created under hard use, and will help minimize warping.

3. The lower grill area of the G6 has ample room to build a cooling duct system for the front brakes. You can find all the parts you need at Home Depot. (don't laugh) One of my corvettes has this, and it has been put to the test at over 200 mph. It works. Most of the parts are found in the vacuum cleaner area. The hose and the attachments you use to scoop up the air are black, so you don't really see them, unless you're looking for it.

4. The next option, is a bit harder, and deals with the proportion brake valve. The trick is finding the right spring, in order to make the rear brakes work a little harder. Right now, as in most passenger cars, the front brakes do most of the work, this also shifts most of the weight to the front under hard braking, causing the even more of a load on the front rotors, which contributes to more heat.

5. Ultimately, the best scenario is going to a bigger diameter rotor which is also thicker, this will require a different caliper and pads. I haven't had a chance to look at the G8 braking system, but it might be adaptable to the G6 with some modifications.

Hope this helps.
-SAM-

[jedi3]

Re: shake in front end at highway speeds

Great tips and explanation

thanks