Odd feeling with rear when at wot or under boost

[DJ-Silver 2SS]

So I figured before I went to beat on my local service department, I'd post here and see what you guys think. Here's alittle background:
13' ZL1, had rear end chatter/noise, so the dealership completed the changing fluid, noise still there, then they ordered a new center section and replaced it about 4-5 weeks ago. Within a couple days after the replacement, I started to hear a loud binding/clunking noise when the rear suspension was articulating indepentantly, like going over a speed bump at an angle, or backing into my driveway. Techs went back over it finding the axle nuts did not maintain their torque and the axles were sliding around about an 1/8"-1/4". Ordered and replaced the axle nuts.
Now my issue, when I am rolling along, and I downshift or just really get into boost, the back of the car sways horribly, like something is not right. I have never had this feeling before and it honestly makes the car a bit uncontrollable. At first i thought I was breaking loose, but it's not. After 10k miles, this concerns me. I know what I'm looking for and at as I have built a few cars, but I don't have a lift available, so now I have to rely on the dealership.... Does anyone have an idea what the issue is, or what I should look at before taking it back to the dealership?

[Sven59]

Is it just swaying or are the tires breaking loose?

[DJ-Silver 2SS]

I just edited that, no the tires are not breaking loose. I thought that at first, but it is not. Something is not right back there.

[u812]

I suggest you don't waste any time with the dealer your using. I also had problem with my 2010 going thru seals grinding. Most dealers just don't know how to work on them.
Took it to Vengeance racing in Cumming and got it fixed right.

[Sven59]

Originally Posted by DJ-Silver 2SS

I just edited that, no the tires are not breaking loose. I thought that at first, but it is not. Something is not right back there.

I would take it back to the dealer again it sounds like something is loose. I have never experienced anything like that, the car is always solid unless the tires are breaking loose.

[DJ-Silver 2SS]

Originally Posted by u812

I suggest you don't waste any time with the dealer your using. I also had problem with my 2010 going thru seals grinding. Most dealers just don't know how to work on them.
Took it to Vengeance racing in Cumming and got it fixed right.

Warranty versus out of pocket. I was up at vengeance about 10 days ago and I will go with them to upgrade, but I am staying with warranty, and the 10 minute drive versus 3 hour drive. Thanks for the idea.

[DJ-Silver 2SS]

Originally Posted by Sven59

I would take it back to the dealer again it sounds like something is loose. I have never experienced anything like that, the car is always solid unless the tires are breaking loose.

It is something new to me. I've never had a car lay over like this. I just wanna have fun with my car..... thanks.

[MMXI SS]

I had a similar issue after some suspension work on my SS. Almost feels loose under hard acceleration. Check the alignment! BTW, I haven't had any issues with the ZL1

[Drew P]

If you dont have a lift, just take it to the dealer and tell them you are a "car freak" and want to accompany the vehicle. I took my car in for some warranty work and they let me back in the bays with the car as they put in on the lift. You can just casually sniff around for yourself while you are back there. Most techs I have dealt with were cool with it based on the car you are bringing in. Just a thought.

[DJ-Silver 2SS]

I will check with the alignment. That's a new one to me. So far the service department is pretty cool. I'll post some info after I get back.

[Chevrolet Customer Svc]

Originally Posted by DJ-Silver 2SS

So I figured before I went to beat on my local service department, I'd post here and see what you guys think. Here's alittle background:
13' ZL1, had rear end chatter/noise, so the dealership completed the changing fluid, noise still there, then they ordered a new center section and replaced it about 4-5 weeks ago. Within a couple days after the replacement, I started to hear a loud binding/clunking noise when the rear suspension was articulating indepentantly, like going over a speed bump at an angle, or backing into my driveway. Techs went back over it finding the axle nuts did not maintain their torque and the axles were sliding around about an 1/8"-1/4". Ordered and replaced the axle nuts.
Now my issue, when I am rolling along, and I downshift or just really get into boost, the back of the car sways horribly, like something is not right. I have never had this feeling before and it honestly makes the car a bit uncontrollable. At first i thought I was breaking loose, but it's not. After 10k miles, this concerns me. I know what I'm looking for and at as I have built a few cars, but I don't have a lift available, so now I have to rely on the dealership.... Does anyone have an idea what the issue is, or what I should look at before taking it back to the dealership?

Apologies to hear of these vehicle concerns. If assistance is needed, please contact us privately and I'll look into this matter further.

Kindest regards,

William R.
Chevrolet Customer Care

[knowitman]

It might not be breaking loose, but it could be the traction control switching back and forth between left and right sides to maintain traction.

[DJ-Silver 2SS]

Originally Posted by knowitman

It might not be breaking loose, but it could be the traction control switching back and forth between left and right sides to maintain traction.

I was kinda thinking the same thing, but its not that. TC and stability are not lighting up either. It feels like the whole car rolls over like an old 4 door sedan that you push into a corner.

[Exigent]

Check the alignment. If it feels like the rear of the car is trying to do the steering, have them pay particular attention to the rear toe-in.