GMC Sierra 2500/3500 2020-2024

Keep your heavy-duty GMC truck performing at its best with the Haynes Repair Manual for the 2020–2024 GMC Sierra 2500HD and 3500HD. Built for serious towing, hauling, and demanding jobsite work, these trucks are engineered for durability and power. This step-by-step repair manual provides the detailed guidance you need to maintain and repair your Sierra HD with confidence. Expert Guidance You Can Trust Every Haynes manual is developed from complete hands-on strip-downs and rebuilds performed by experienced technicians and editors. The result is a clear, practical guide packed with step-by-step instructions, torque specifications, detailed illustrations, and helpful tips that make even complex repairs easier to understand. Whether you’re performing routine maintenance or tackling major repairs, this manual helps you save money and keep your truck running like new. Models Covered GMC Sierra 2500HD (2020–2024) GMC Sierra 3500HD (2020–2024) Engines Covered 6.6L V8 Turbo-Diesel Duramax (L5P) 6.6L V8 Gasoline (L8T) – Online coverage Common GMC Sierra 2500 / 3500 Issues (and How This Manual Helps) Duramax DEF system warning lights – Diagnose emissions issues and service SCR components commonly appearing after 60,000 miles. Turbocharger performance loss – Inspection, troubleshooting, and replacement procedures often needed around 80,000 miles. Allison transmission shifting delays – Fluid service procedures and diagnostic checks for trucks with 50,000+ miles. Suspension wear and steering play – Step-by-step replacement for bushings, tie rods, and ball joints. Brake system servicing – Detailed procedures for rotor and brake pad replacement plus ABS sensor diagnostics. Cooling system leaks – Water pump and radiator replacement to prevent overheating during heavy towing. Driving Habits That Impact Maintenance Snow plowing or rough terrain – Accelerates suspension wear; this manual includes full component replacement procedures. Frequent towing and hauling – Adds stress to brakes and turbo systems; detailed servicing and repair instructions included. High mileage driving – Regular fluid changes and cooling system checks are critical; service intervals and troubleshooting flowcharts are provided. Older or high-mileage trucks – Covers common issues like timing chain wear and ABS sensor failures with clear repair guidance. What’s Inside the Haynes Repair Manual Complete maintenance, repair, and rebuild procedures Factory torque specifications and technical data Service schedules and fluid capacity charts Troubleshooting flowcharts for drivetrain, DEF system, electrical, and cooling systems Detailed coverage of brakes, suspension, steering, HVAC, bodywork, and wiring Hybrid format: printed manual plus online technical coverage From routine maintenance to complex repairs, the Haynes Repair Manual for the 2020–2024 GMC Sierra 2500HD and 3500HD gives truck owners and technicians the knowledge needed to get the job done right.