1991 GMC R3500

Introduction: The 1991 GMC R3500 is a heavy-duty pickup truck that was available with various engine and transmission options. It is known for its powerful engines and rugged construction. The R3500 was well-regarded for its capabilities but also had some common issues.

Engine

5.7L V8

• Intake manifold gasket failure: Description/Symptoms: Coolant or oil leaks, overheating, poor engine performance. Solution: Replace the intake manifold gasket. Estimated Cost to Fix: $500 - $1000+
• Valve train noise: Description/Symptoms: Ticking or tapping noises from the engine. Solution: Replace the lifters or timing chain. Estimated Cost to Fix: $1000 - $2000+

7.4L V8

• Fuel injector failure: Description/Symptoms: Engine misfires, rough idle, poor fuel economy. Solution: Replace the fuel injectors. Estimated Cost to Fix: $500 - $1000+
• Ignition coil failure: Description/Symptoms: Engine misfires, hard starting, no spark. Solution: Replace the ignition coil. Estimated Cost to Fix: $200 - $500

Transmission

4L80E 4-speed automatic

• Transmission slipping: Description/Symptoms: Gears slip or hesitate during shifting. Solution: Rebuild or replace the transmission. Estimated Cost to Fix: $2000 - $4000+
• Torque converter shudder: Description/Symptoms: Vibration or shuddering during acceleration. Solution: Replace the torque converter. Estimated Cost to Fix: $1000 - $2000

TH400 3-speed automatic

• No issues found

Suspension

• Rear leaf spring failure: Description/Symptoms: Sagging rear end, uneven tire wear. Solution: Replace the leaf springs. Estimated Cost to Fix: $500 - $1000+
• Ball joint wear: Description/Symptoms: Loose steering, clunking noises. Solution: Replace the ball joints. Estimated Cost to Fix: $200 - $500 per joint

Electrical

• Alternator failure: Description/Symptoms: Dim headlights, battery drain, charging system warning light. Solution: Replace the alternator. Estimated Cost to Fix: $500 - $1000+
• Battery failure: Description/Symptoms: Difficulty starting, dead battery, corrosion on terminals. Solution: Replace the battery. Estimated Cost to Fix: $100 - $200

Exterior

• Rust on body panels: Description/Symptoms: Surface rust, pitting, holes. Solution: Repair or replace the affected panels. Estimated Cost to Fix: Varies depending on the extent of damage
• Headlight switch failure: Description/Symptoms: Headlights not working, intermittent operation. Solution: Replace the headlight switch. Estimated Cost to Fix: $200 - $500

Interior

• HVAC blower motor failure: Description/Symptoms: No air flow from vents. Solution: Replace the blower motor. Estimated Cost to Fix: $200 - $500
• Instrument cluster failure: Description/Symptoms: Gauges not working, erratic readings. Solution: Replace the instrument cluster. Estimated Cost to Fix: $500 - $1000+

Summary: The 1991 GMC R3500 is a capable truck but does have some common issues. Engine and transmission problems can be costly to repair, while suspension and electrical issues are typically less expensive. Rust and interior issues are also common but can vary in severity and repair cost. Overall, the R3500 is a reliable vehicle but owners should be aware of the potential issues before purchasing one.