NHTSA Complaint #11714021 — 2024 CHEVROLET SILVERADO 3500

NHTSA Vehicle Safety Complaint I am reporting a serious transmission defect in my 2024 Chevrolet Silverado 3500HD LT that creates a high risk of sudden power loss, erratic shifting, or loss of control while driving. Vehicle Details: - Make/Model/Year: Chevrolet Silverado 3500HD LT, 2024 - VIN: 2GC4YTEYXR1263768 - Engine: 6.6L Duramax diesel - Transmission: 10-speed Allison (10L1000) - Mileage at diagnosis: ~46,000 miles - Title: Rebuilt (warranty denied due to branding) Defect Description: The transmission shifts normally when cold (fluid below ~138°F). Once warm (during normal driving), it fails to upshift properly in gears 5-8: holds lower gears, causes high RPMs (3,000+), delays shifts excessively, or refuses to shift. When shifts occur, they are hard and jerky. Automatic (Drive) mode is affected; manual/L mode works normally as a workaround. No warning lights appeared initially, but the issue has worsened and is now frequent at operating temperature. Diagnosis: On January 28, 2026, Seminole GM (1405 N Milt Phillips, Seminole, OK 74868; 405-382-6130) diagnosed a defective valve body requiring replacement. Quote: - Valve Body Control Module (Part #24065357): $687.48 - Transmission Fluid (12 qt @ $10.92): $131.04 - Labor (diagnosis + pan/filter/relearn): $805.50 - Supplies/taxes: ~$140 - Total: $1,763.94 Dealer confirmed this is a common issue; photos of quote available for upload. Safety Risks: At highway speeds, delayed/no upshifts can cause: - Sudden inability to accelerate (merging, passing, hills) - Harsh engagement leading to wheel slip or loss of control - Potential limp mode entry, stranding in low gears This intermittent warm-only failure is unpredictable and dangerous. Context: This matches widespread complaints on 2023-2025 GM HD trucks with the 10L1000 (forums: DuramaxForum, Reddit r/Duramax/r/Silverado, GM-Trucks.com), involving valve body wear/pressure loss. Earlier years had related recalls (e.g., NHTSA 24V-797 for valve issues),