2024 GMC Sierra 3500 HD Service and Repair Manual

This factory service and repair manual for the 2024 GMC Sierra 3500 HD accounts for six trims: AT4, Denali, Denali Ultimate, Pro, SLE and SLT. Body coverage runs to five configurations, from four-door crew cab and extended cab pickups to a two-door standard cab pickup and cab and chassis units with four or two doors. Both engines measure 6.6 liters — the turbocharged diesel V8 at 403 cubic inches, the naturally aspirated gasoline or flex-fuel V8 at 401 — and both are overhead-valve.

Engines covered

• 6.6L V8 (403 cu in) — OHV, turbocharged, diesel
• 6.6L V8 (401 cu in) — OHV, naturally aspirated, gasoline or flex-fuel

Body styles covered

• 4-door crew cab pickup
• 4-door extended cab pickup
• 4-door cab & chassis
• 2-door cab & chassis
• 2-door standard cab pickup

Trims covered

• AT4
• Denali
• Denali Ultimate
• Pro
• SLE
• SLT

Known issues on the 2024 Sierra 3500 HD. Three recalls attach to this model year. The gravest is a steering gear shaft that can fracture and part from the steering arm, taking away steering control altogether. The other two both concern the power-unlatching tailgate, where water reaching the gate-release switch can short it and let the gate drop open while the truck is moving, spilling loose cargo. Of 44 complaints, power train leads, then the electrical system and service brakes. Steering, wiring and brake diagnostics are all set out in this manual.