2023 Chevrolet Silverado 2500

Component/System: The Allison 10‑speed (10L1000) transmission valve body catastrophically failed on [XXX], while driving Sunday afternoon down Galveston Seawall Blvd. The truck abruptly dropped from 45 mph into limp mode in heavy traffic, forcing me to pull into the bike lane to avoid being rear‑ended. The vehicle remains at Classic Chevrolet (Galveston, TX) awaiting the OEM valve body—which is on national backorder—and the complete transmission assembly is likewise unavailable. The failed valve body and transmission are available for inspection upon request. Safety Risk: Unexpected limp mode and gear lock‑up in heavy traffic create an immediate risk of rear‑end collisions or side impacts as surrounding drivers have no warning of sudden deceleration or loss of drive. Reproduction/Confirmation: Classic Chevrolet diagnosed and confirmed the failed valve body on May 12, 2025. Their service advisor and my assigned GM Case Agent (#[XXX]) have both acknowledged the defect but report no parts available for repair. Inspections: The vehicle has been inspected by Classic Chevrolet under warranty. GM Customer Care has reviewed my service orders and correspondence. No police or insurance inspections occurred, as no collision ensued—however, the roadside inspection at Classic Chevrolet confirmed the mechanical failure. Warnings/Symptoms: There were no prior warning lamps, messages, or symptoms before the failure. The valve body failure occurred without any advance indication. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)