What is the contact info for the Part Allegation department? Most people would be out of their minds that their car has been down for almost 9 months, yet your first post is a question if ball joints are an issue. Please posts pics of the damage. GM won't walk away on a safety related failure item because that just opens them up to lawsuits that could cost them millions of dollars. How do you use your warranty BEFORE you take it to a dealership????

 

Start with calling their Customer service number 1-800-284-2271 to start your case. Part Allegation Department number that I called was 1-866-446-6963. After you notify them, they will likely advise you to then take it to the dealership. This is what I gather from their advice. At least that way they will have less reasons to excuse themselves from not addressing the problem.

 

The number shown is the dealer direct access # into the PAC (Product Assistance Claim) team is 866-446-6963, it is not intended for customers. Customers are supposed to call 800-231-1841.

Post pics of the damage please.

 

I'm surprised your car is not a total loss. **** happens, cars are not like aircraft where every nut, bolt, component has non-destructive testing and certification. I'm sure there are many suspension components that have stress fractures, inclusions and other flaws that get used in new car assembly. It's easier and cheaper for manufactures to deal with it and warranty those claims than totally prevent them.

Yes, photos of the damage please.

 

This is very interesting. I had a total brake failure event while tracking my 2021 C8 Z51.

People have disputed what I said happened because they think the failure was due to brake fluid boiling. Supposedly the pedal should get spongy as compressible bubbles are formed in the fluid. I didn't get ANY sort of warning message on the DIC. I could feel a slight difference in brake feel in the corner prior to the failure, but it wasn't a corner that you enter at super high speed and the braking zone was very short there, so I just didn't think to "knock it off" and pressed on into the higher speed turn that happens to be high banked with a guard rail. I often brake semi-late and hard going into braking zone before entering balance. The brakes just totally gave out and the DIC screen said "BRAKE SYSTEM FAILURE" with a solid red background. The pedal became super stiff and there was just no braking feel whatsoever. I was inches away from hitting the wall, but managed to make the turn and then drove straight off the track to cool the brakes down. Had to do the reset procedure to get the car out of limp mode.

I had paid the local chevy dealer to install Motul 660 RBF and I had some question in my mind after this failure if they properly installed that RBF. I also had the fluid in the car for nearly a year and have heard that Motul 660 doesn't last that long.
I have since switched to Castrol SRF and brakes have been working fine since then. I checked them very closely and didn't see any issues with pistons or calipers. I put my carbotech street pads back on and haven't tracked it since then because I also have an odd "crunching" sort of sound coming from the front suspension.
It started on the right side of the car, but now both the left and right side are making a metallic sort of crunch when going over uneven pavement, but going over curb into my driveway doesn't do it. I am thinking it is either a problem with my ARB/sway bar, problem with MSRC shocks (due to paragon lowering collars 3/4"), but am a bit concerned that it could be some sort of crack in the suspension developing. I saw a picture of a tracked C8 that tore through some of the aluminum in the front where the upper control arm mounts. There is an area there that is weak. On visual inspection, everything looks great! I have no DOT4 leaks around front end lift, banjo's, shocks look mint, bellows aren't crumpled, lift works as good as new. MSRC system works and you can feel night/day difference in ride feel so I have to assume the MSRC shock internals are good. I just have this god awful CRUNCHING (see attached around the 0:27 second mark) sound and so I have been very hesitant to go back on the track with it.