The GMC Sierra is one of the best-selling trucks in America — but recent model years have drawn a wave of serious engine and transmission complaints, several of them serious enough to trigger nationwide recalls. If your GMC truck keeps going back to the dealer for the same unresolved problem, it may qualify as a lemon under California law. Here are the defects owners report most, and what they mean for a potential claim.
Quick answer: The GMC truck problems most commonly tied to lemon law claims include 6.2L V8 engine failures, 10-speed and 8-speed transmission defects (harsh shifting, shudder, and rear-wheel lock-up), and lifter/valvetrain issues. If a defect substantially impairs your truck’s use, value, or safety and GMC can’t fix it after a reasonable number of attempts, you may be entitled to a refund or replacement.
Does California lemon law cover GMC trucks?
Yes. California’s lemon law — the Song-Beverly Consumer Warranty Act — covers GMC vehicles, including the Sierra and Canyon, as long as the truck is under the manufacturer’s original warranty (or was sold Certified Pre-Owned with a new warranty). GMC is part of General Motors, and the same protections that apply to other defective trucks apply here. The starting point is confirming your truck qualifies as a lemon.
The most commonly reported GMC truck problems
Based on complaints filed with the National Highway Traffic Safety Administration (NHTSA) and patterns lemon law attorneys see most, these are the issues driving the most recent GMC truck claims:
- 6.2L V8 (L87) engine failure. In April 2025, GM issued recall NHTSA 25V274 covering roughly 600,000 2021–2024 trucks and SUVs — including the Sierra 1500 and Yukon — with the 6.2L L87 V8, citing manufacturing defects in connecting rods and crankshafts that can cause sudden loss of power, knocking, or complete engine failure. The remedy can require a full engine replacement.
- 10-speed transmission defects. In late 2024, GM recalled roughly 462,000 diesel trucks and SUVs (including Sierra models) for a transmission control-valve defect that can cause harsh shifting and, in rare cases, the rear wheels to lock up. The fix is typically a software update — which doesn’t always end the problem.
- 8-speed transmission “shudder.” The 8L90/8L45 8-speed has been linked for years to light-throttle shudder, vibration, and rough shifting (often called the “Chevy Shake”), generating 60-plus technical service bulletins and class-action litigation.
- Lifter and valvetrain issues. The V8 engines’ cylinder-deactivation systems (AFM/DFM) have drawn complaints of ticking or tapping, misfires, and sudden power loss, sometimes requiring lifter, camshaft, or full engine replacement.
- Electrical and other defects. Reported issues include power tailgates opening unexpectedly (traced to water intrusion in the switch), instrument-cluster malfunctions, a low-brake-fluid warning-light software defect, and daytime running lights that stay on.
Why recalls and TSBs matter for your claim
A recall or technical service bulletin is an official acknowledgment that a defect is known to the manufacturer. That can be powerful evidence in a lemon law case — especially when the prescribed “fix” is a software update or calibration that doesn’t actually resolve the problem. If your truck keeps exhibiting the same defect after the recall remedy or repeated dealer visits, that recurring failure is exactly what a lemon law claim is built on. Ask your dealer to check your VIN for open recalls and document every visit.
When a GMC truck qualifies as a lemon
A defect rises to a lemon law claim when it substantially impairs the vehicle’s use, value, or safety, the truck is under warranty, and GMC has had a reasonable number of attempts to fix it without success. For serious safety defects — like loss of propulsion or a transmission that can lock the rear wheels — as few as two repair attempts may be enough. Keep every repair order, note the mileage and dates, and track how many days the truck spent in the shop. See how the process works for the full sequence.
A note on the transmission class action
In June 2025, a federal appeals court decertified the nationwide class action over GM’s 8-speed transmission, meaning affected owners generally can no longer rely on a single group settlement — claims now proceed case by case. For many California owners, that makes an individual lemon law claim one of the clearest paths to a refund or replacement.
What you can recover
If your GMC truck qualifies, the manufacturer may have to repurchase it — refunding what you paid (price, taxes, fees, and finance payments) minus a mileage offset — or provide a replacement. You may also recover incidental costs like towing and rental, and, where the violation was willful, a civil penalty of up to two times your damages. Our buyback guide explains how the refund is calculated, and you can see representative outcomes on our case results page. Because California shifts attorney’s fees onto the manufacturer when you win, this costs you nothing out of pocket.
Think your GMC is a lemon?
American Lemon Law Group will review your truck’s repair history at no cost and tell you whether you have a claim. You can also look up open recalls on your VIN through NHTSA’s recall lookup. Call (877) 311-1133 or request a free case evaluation.
This article is for general informational purposes only and is not legal advice. Defect and recall descriptions reflect information reported by NHTSA, GM, and vehicle owners, not a finding about any specific vehicle. Every case is different and outcomes depend on its facts. Consult a qualified California lemon law attorney about your situation.