HomeAll RepliesReply To: 2021 GMC Sierra 1500 AT4 Lifter Collapse Reply To: 2021 GMC Sierra 1500 AT4 Lifter Collapse Sponsored July 15, 2024 at 10:01 pm #821914 bronnyParticipant 3,643 miles? wow, barely broken in. should definitely be covered under warranty. Sponsored Subscribe to GM Authority For around-the-clock GM news coverage We'll send you one email per day with the latest GM news. It's totally free. First Name Last Name Email Address Subscribe via Email Leave this field empty if you're human: Sponsored