Positioning:
The Chevrolet S10 Pickup was a highly popular compact pickup truck, known for its versatility, affordability, and capability, making it a strong competitor against models like the Ford Ranger and Toyota Hilux/Tacoma.
Analysis:
The 1991 S10, part of the GMT400 platform, offered a blend of ruggedness and passenger-car comfort, appealing to both work and personal use. This manual provides the essential information for owners and technicians to maintain and repair this successful model.
Features:
User-friendly step-by-step instructions with accompanying pictures, extensive coverage of all models/engines/trims, and the ability to print specific sections or the entire manual.
Description:
Complete service and repair procedures for all aspects of the 1991 Chevrolet S10 Pickup, including engines, transmissions, chassis, body, and electrical systems.
Estimated:
1500-2000+ (estimated based on typical comprehensive workshop manuals of the era)
Type:
Workshop Service Repair Manual
Engine:
Detailed diagnostics, overhaul, and repair for all available engines (e.g., 2.5L Iron Duke, 4.3L Vortec V6).
Transmission:
Service and repair for manual (e.g., NV3500) and automatic (e.g., TH700R4/4L60) transmissions, including torque converters and clutch systems.
Drivetrain:
Front-wheel drive (FWD) and rear-wheel drive (RWD) configurations, including differentials, axle shafts, and driveshafts.
Suspension:
Front independent suspension (torsion bar or coil spring depending on configuration), rear leaf spring suspension, shock absorbers, and steering components.
Brakes:
Front disc and rear drum brake systems, hydraulic lines, master cylinder, power booster, parking brake.
Electrical:
Comprehensive wiring diagrams, starter, alternator, battery system, lighting, ignition system, fuel injection system (TBI/MPI), and instrument cluster diagnostics.
Body:
Exterior body panels, doors, hood, tailgate, interior trim, seats, glass, and weatherstripping.
HVAC:
Heating, ventilation, and air conditioning system servicing and repair.
Maintenance:
Oil changes, filter replacements, fluid checks and changes, spark plug replacement, belt adjustments, brake fluid flushes.
Diagnostics:
Troubleshooting charts for common symptoms, diagnostic trouble codes (DTCs) for applicable electronic systems, electrical system fault finding.
Repair:
Engine rebuilds, transmission overhauls, suspension component replacement, brake caliper and rotor replacement, starter/alternator R&R, fuel pump replacement.
Installation:
Component installation procedures, e.g., replacing radiator, power steering pump, exhaust system components.
Specifications:
Torque specifications, fluid capacities, diagnostic data, electrical resistance values, alignment specifications.
Depth:
Comprehensive, covering from basic maintenance to major component overhaul and in-depth electrical system diagnostics.
2.5L I4:
Engine Code: LQ5 (Iron Duke). Displacement: 2.5 Liters (151 cu in). Horsepower: Approx. 105-112 hp. Torque: Approx. 130-140 lb-ft. Fuel System: Throttle Body Injection (TBI).
4.3L V6:
Engine Code: LB4 (Vortec V6). Displacement: 4.3 Liters (262 cu in). Horsepower: Approx. 160-165 hp. Torque: Approx. 230-235 lb-ft. Fuel System: Throttle Body Injection (TBI).
Hp Range:
105 - 165 hp (depending on engine option)
Torque Range:
130 - 235 lb-ft (depending on engine option)
Type:
Throttle Body Injection (TBI) for both engines. Some later models introduced Multi-Port Fuel Injection (MPI) on the 4.3L, though less common in '91.
Capacity 2.5L:
Approx. 11.0 Quarts
Capacity 4.3L:
Approx. 13.0 Quarts
Type:
Electronic Spark Control (ESC) and Single Point Ignition (SPI) or Distributorless Ignition System (DIS) depending on engine.
Manual Transmission:
New Venture Gear NV1500 (5-speed manual) often standard on base models with 2.5L engine.
Automatic Transmission:
Turbo-Hydramatic 700R4 (later designated 4L60) 4-speed automatic transmission available with both engines.
Manual Transmission V6:
New Venture Gear NV3500 (5-speed manual) likely available with the 4.3L V6.
Fluid Type Auto:
Dexron-III (or equivalent)
Fluid Capacity Auto:
Approx. 9.5-11.5 Quarts (depending on specific model/transmission)
Fluid Type Manual:
GL-4 Gear Oil (e.g., 75W-90 or 80W-90)
Fluid Capacity Manual:
Approx. 2.0-2.5 Quarts
Wheelbase Standard:
118.2 inches
Wheelbase Long:
122.5 inches (available on some configurations)
Bed Length Standard:
6.5 feet
Bed Length Long:
7.5 feet (on long bed models)
Curb Weight Min:
Approx. 3,000 lbs (2WD, 4-cyl)
Curb Weight Max:
Approx. 4,000 lbs (4WD, V6, long bed)
NHTSA Rollover 1991:
N/A (NHTSA did not provide star ratings for rollover in this era)
IIHS Crash Data:
Data from this period is less granular; focus would be on general structural integrity and occupant protection systems.
ABS:
Anti-lock Braking System (ABS) was often an optional feature, typically on rear-wheel anti-lock (RWAL) systems.
Airbags:
Driver-side airbag was standard equipment for 1991.
Seatbelts:
Front three-point manual seat belts; lap belts for center occupants if applicable.
Audio System:
Basic AM/FM radio, optional cassette player. Aftermarket head units commonly installed.
Gauges:
Analog gauges for speedometer, tachometer (optional), fuel, oil pressure, coolant temperature, and voltmeter.
Cruise Control:
Optional feature on most trim levels.
Connectivity Options:
Limited to the era; no integrated Bluetooth or USB ports. Aftermarket solutions available.
Oil Change:
Every 3,000 - 5,000 miles or 3-6 months (depending on oil type and driving conditions).
Air Filter Replacement:
Every 12,000 - 15,000 miles or annually.
Spark Plug Replacement:
Every 30,000 - 60,000 miles (depending on spark plug type - standard copper vs. platinum).
Transmission Fluid Service:
Automatic: Every 30,000 - 50,000 miles. Manual: Inspect periodically, change as needed or at higher mileage intervals (e.g., 60,000-100,000 miles).
Coolant Flush:
Every 30,000 - 50,000 miles or 2-3 years.
Engine Oil Grade:
10W-30 (or 5W-30 for colder climates) meeting API SF or SG service classification.
Power Steering Fluid:
ATF Dexron-II or Dexron-III
Common Problems:
Rust on cab corners and bed, ball joint wear (especially on early GMT400), exhaust manifold leaks on V6, potential intake manifold gasket leaks on later models (less common in '91), starter motor failures, catalytic converter issues.
Oil Filter Part Number Example:
AC-Delco PF2 (or equivalent like Fram PH8A, WIX 51085)
Air Filter Part Number Example:
AC-Delco A3033C (or equivalent)
Heritage:
Chevrolet has a long history of producing reliable and capable trucks, dating back to the early 20th century. The S10 marked a new era for their compact pickup offerings.
Generation 1991:
The 1991 model year is part of the first generation of the S10 Pickup, built on the GMT400 platform. This generation was a significant redesign, moving to a more modern unibody construction with a separate frame.
Manufacturing Locations:
General Motors assembly plants across North America, including locations like Shreveport, Louisiana, and St. Louis, Missouri.
Production Years Platform:
GMT400 platform production: 1982-2004 (with significant updates and facelifts).
