I have an issue with my C5 Z51 pulling slightly right when under acceleration and then moving slightly left with de-acceleration. I have new tires on the car and have had it completely aligned three times. The issue feels like the rear is trying to steer the car depending on power. The car also seems to make a slight left/ right movement when changing lanes. Basically, the car does not track straight and needs small but constant steering corrections.

The shocks are new and I have replaced the front and rear sway bar links. The car has 50k miles on it now; however, it has been steering like this since I purchased it with 30k miles. Not a lot of steering, just enough to make the car unpleasant to drive. I have owned three previous C5's, a C6 Z51, and I currently own a C6 Z06. None of the other cars have had an issue like this one. I am aware of how wide tires affect a car. This car has factory wheels and factory size non-run flat tires. The car has never been in an accident or had frame damage.

Has anyone had issues with the suspension bushings or toe links causing the car to self-steer? Since the car has been aligned three times by two different shops without improving the steering, I do not think alignment is the complete issue. The alignment shops say the suspension is fine; however, they did not make any checks while I watched each time the car was aligned. My experience with many alignment shops is that they really want to take the money and tell me to go on down the road, they do not seem to want Corvette alignments.

 

Moved to C5 Tech.

 

I would take it to a shop that specializes in corvette repair and alignments. They know these cars inside and out.
I wouldn't let any joe schmo mess with it. It may cost a little more but it's worth it.
Good luck getting it figured out.

 

One possibility which occurs to me is that a suspension arm, or mount, is bent. Or could be something weird with the differential? But first step would probably be checking for slop or compliance in the suspension joints.

 

I would not think the suspension parts are worn out at 50,000 miles. Sounds like the toe is off. Toe out gives the instability feeling. But if something is worn in the rear suspension, should be able to find it. Are you able to post a picture of the alignment sheets?

 

most every road in the world is “crowned” to facilitate rain runoff. If the rear thrust is not zero, or the align shops screwed up front caster, you may have this condition The other is a bad steering rack mount bushing, loose mount bolts, or the rack is damaged. Then the rear toe links could have worked loose where they attach to the cradle. though not likely, how about a bad wheel bearing. Tires should be replaced if they are over 5 years old redgardless of condition. Has the car been lowered and no alignment done afterwards. Lowering changes all settings. consistent tire pressure? in the summer you really don’t want your tires getting much above 37-38 psi, Keep an eye on wear. The center of the tread should wear the same as the corners on a properly aligned car.

Tire wear will tell a lot about what is going wrong. Especially the corners. If you run your hand both ways on the tire corners (the transition from side wall and tread surface) and you feel the leading edge of the tread blocks are raised, that is a sign of poor toe settings. If one corner is worn more than the other will give a clue as to which way toe is off. However it is the combination of camber and toe that should be considered.

The Hunter alignment machines are great, and you get a neat little report with green boxes where the alignment is in spec. Unless the toe is set at ZERO both front and back , you will get corner wear. This is a street car setting for maximizing tire life. All the little boxes can be green and you can still have a F-U alignment. That is where you know the tech is weak at knowing cause and effect of alignment settings. One of the previous posters suggested you post your alignment reports. Good idea. It may show how skilled the alignment tech really are.

Cars with wide tires, lots of power, and large contact patches need to be carefully aligned, not just “aligned to spec”. Anyone that bought a C6Z can tell you horror stories about tire life. They assumed the factory alignment was good. We had a ‘11 Grand Sport, mostly driven by my wife that corded a tire at 8k miles. I do my own alignment and didn’t bother to look at her toy (shame on me).

 

I do not have them ATT. They all read within specifications ATT. I watched the entire alignment three times and would not think two different shops would make the same mistakes. I told the techs that the car has the Z51 suspension.

 

I am certain that none of the suspension components are bent. The handling issues are not at the extremes where the positraction or active handling seems to be involved. The pull right under acceleration is the same if just barely accelerating or if hard acceleration. It almost feels as if the right rear wheel is moving forward or the toe is changing under power which pushes the car right. I have to steer slightly left to compensate. As soon as I let of the accelerator, the car moves left until I steer back right to the original centered position. This occurs on smooth-level roads. All my tires are new, factory specified sizes of Nitto N555 set at the correct pressure.

The car does not have any marks under it which would indicate that it ever struck anything. There is not any indication or Carfax report that this car has ever had any repairs from body or chassis damage.

Unfortunately, I live in a rural area. The closest quality Corvette repair shop is over 200 miles away.

 

you can get a terrible alignment within specs. Having a Z51 suspension only gives you bigger sway bars, Stiffer spring and shock to match. None of that will affect a good alignment. You need someone that knows Corvettes to go over everything. Alignment guys often to not give the suspension a good going-over

The car has been aligned twice. What was changed from the first to the second alignment. That, at least might tell you which end of the car to focus on first. You might use your DIC to pull codes and see if there are any codes related to the steering wheel sensor. Kind of a long shot, but the SWPS, Yaw sensor, etc all input to stability control and traction control. Do you messages on the DIC like TC activated, or AH activated when the problem occurs?. That’s what I’d do with a drive test to duplicate the problem.

 

There are not any codes displayed and the condition is continuous.

The first alignment was because I felt the car did not handle well after I bought it. I installed new tires and had it aligned again. I was still not happy with the way the car drove so I had it aligned a third time. Most of the alignment values changed each time in front and rear. I really do not think alignment shops even with the best equipment can install the laser wheel alignment reflectors accurately on the wheels much better than half of a degree. I would need to drive 200 to 250 miles to a larger city where I can find a shop that specializes or has a lot of knowledge about Corvettes. Perhaps the fact that each alignment shows changes are needed is an indication that something is worn and does not remain in the correct position. I might try to check the car myself in my garage before any additional alignments. My initial thought is that the toe-in is changing under power and causing the car to steer accordingly. I can feel the car try to steer right with barely enough acceleration to change speed.

 

where do you live? If you find someone that tracks their C5, we are usually budget constrained and know how to correct poor handling issues. In reality, the suspension is elegantly simple. There is no magic dialing one in, and the C5 is a superb handling car.

I sense you suspect something is loose that the alignment guys aren’t checking. I named a few possibilities Even with 40k miles, the history may not be known unless you bought it new or know the previous owner..

Front Upper control arms The fronts bolt to the frame check the torque car jacked up wheel removed.
Rear upper control arms. Look for a missing bolt, or welds of the bolt pocket broken or distorted.
Check the ball joints for wear and loose nuts.
Wheel back on still in the air. Have an assistant hold the steering wheel still. use all your strength to check in-out movement vertically and horizontally. The movement of any wheel should be tiny, like .005 inches. If the slop is bigger, start looking for the source.
Check the 2 bolts that mount the steering rack to the cradle. These bolts are a bitch, and one goes through a shock absorbing bushing. Pry the rack to see if it goes up. Those shock absorbing bushings are getting 20YO, common to find a bad one
with the tires taking the weight of the car have a assistant turn he steering wheel. make sure even small steering wheel inputs make a change
Delaminated leaf springs, doubt that is a problem
Bad sway bar end links, or the two bushings where the sway bar is attached to the cradle. The sway bar needs to slide and rotate in those two bushings to work properly. Ditto rear sway bar
Do the same wheel shake to the rear wheel.

I’m about to pour a glass of Jameson. Good Irish whisky may clear brain fog. I may have some more things to look at.

 

Thanks. These are some issues I did not know about. I will check them as soon as I get back from entering my C3 in a multi-day show. I did replace the front and rear sway bar links...the bushings in those links were deteriorating.

Something must be a bit loose and I might be a bit picky as to how my car drives. I expect it to be as good as my previous C5's and C6's.

Thanks..