2021 GMC Sierra 1500 Suspension Problems

Vehicle: 2021 GMC Sierra SLT | VIN: [XXX] Dealership: Carl Black GMC Roswell, GA (11225 Alpharetta Hwy, 30076) | Invoice #[XXX] | Service Date: [XXX] Paragraph 1 – Suspension Hazard: Dealership diagnosed a worn left upper ball joint (popping sound on left turns) and installed Rough Country aftermarket upper control arms on my stock-height Sierra SLT. These arms are designed for lifted suspension and alter factory caster/camber geometry, placing extreme stress on ball joints. This can cause sudden ball joint separation, wheel collapse, and total loss of steering control at speed. The dealership admitted on the invoice they "could not find branding" on original parts and chose non-OEM lift components without my consent or any safety disclosure. Paragraph 2 – Brake Failure & No Safety Warning: The same service included a full front/rear brake job (pads + resurfaced rotors) using their certified technicians and parts. After pickup, the brakes failed to operate properly. When I returned, the service manager refused to correct their own workmanship and instead quoted $1,900 to repair the very brakes they just serviced. Most critically, at vehicle pickup they issued no written or verbal safety warning—no "do not drive" instruction—despite the brakes being knowingly compromised, endangering me and the public. Paragraph 3 – Requested Action: The service manager was unprofessional, condescending, and refused accountability. I request an immediate NHTSA investigation into Carl Black GMC's unauthorized use of lift-kit suspension parts on stock vehicles, failure to warranty their own brake service, and reckless omission of safety warnings at delivery. This dealership pattern poses an imminent public risk. Please escalate. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11752674

Incident

Jul 16, 2026

The contact owns a 2021 GMC Sierra 1500. The contact stated that while her son was driving 55 MPH and depressing the brake pedal, the vehicle failed to slow down as intended. The driver attempted to use the parking brake to slow the vehicle, but the vehicle failed to slow down. The message “Braking System Failure” was displayed. The driver pulled over to the side of the road, and the passenger’s side front wheel detached and started leaning to the right before the vehicle came to a stop. The driver exited to inspect the vehicle and became aware that the front passenger’s side wheel was lying on the ground. The vehicle was towed to an independent mechanic, but was not diagnosed. The vehicle was then towed to another dealer, where it was diagnosed, and it was determined that the passenger’s side upper and lower control arms, ball joints, rack and pinion, brake rotor and pads, hub, outer tie rod, brake line, speed wheel sensor, wheel and tire, and suspension parts needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 77,000.

NHTSA ID

11733285

Incident

Apr 17, 2026

Mileage

77,000 mi

Transmission Shuttering which was confirmed from from GMC dealership , but refused to do any repairs after confirmation or diagnostic and test driving. Demanded a 220$ fee be paid before releasing my vehicle back. Also gave GMC Bulliten # 25-NA-148 which states the same issues I'm currently having.

NHTSA ID

11722823

Incident

Feb 13, 2026

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, there was an abnormal clunking sound coming from the rear suspension. The check engine warning light was illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the rear suspension. The vehicle was repaired, but the failure reoccurred 4,000 miles later. The contact stated that while reversing, the contact heard an abnormal clunking sound coming from the rear suspension. The contact also stated that there was also a strong antifreeze odor permeating the interior of the vehicle. The vehicle was taken back to the dealer, but not yet diagnosed. The vehicle was not repaired. The manufacturer was notified of the failure, and a case was opened. The failure mileage was 38,000.

NHTSA ID

11640645

Incident

Feb 4, 2025

Mileage

38,000 mi

Front upper control arm ball joint separated from socket.

NHTSA ID

11628321

Incident

Nov 13, 2024

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving 40 MPH, the front driver's side wheel separated and fell underneath the front end of the vehicle, causing the vehicle to veer towards oncoming traffic. The contact was able to pull to the side of the road, where the vehicle was awaiting to be towed. The contact related the failure to NHTSA Campaign Number: 21V718000 (Suspension); however, the VIN was not included. The dealer was notified of the failure. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was 37,470.

NHTSA ID

11590543

Incident

May 24, 2024

Mileage

37,470 mi

I took my truck to the dealership because of my issues and they said they had many trucks going in with the same issue but there was no fix to it. The issues Popping Noise Heard On Hard Turns and/or Going Over Speed Bumps, Creaking Noise While Turning Wheel Left and/or Right, Clicking Noise Heard On Slow Sharp Turns.Also when you go over a bump the truck makes a spring loud noise to the point that the whole truck bounces. shifter is also very hard when you try to change gears.

NHTSA ID

11479962

Incident

Jun 1, 2022

On 22 December 2020, I received a 2021 GMC Sierra 1500 SLT X31 Truck. The day that I drove it I notice that the Truck was riding as though it had a low Tire issue. It was riding bouncy. I had no low tire light. I checked the Tire Pressure and they all was over inflated. I brought the pressure back to range, but the Truck was riding the same over rough and bumpy roads that the rear end of the Vehicle was shifting from side too side when you hit a bumpy or on rough roads. it felt like the rear end was coming off the ground very frighten. I called GM they assigned a case number and I took the Truck to Three dealership with the same answer that all bolts were tighten to Spec. Ok I get that, but did not address the problem that the truck is doing. I am not comfortable driving this truck especially when you have no I deal when your terrain will change and the back end of y0our Vehicle moves from side to sider on you.

NHTSA ID

11430578

Incident

Dec 22, 2020