🏷️ Basic Information

Make:

Chevrolet

Model:

C/K

Model Range:

C/K 1500, C/K 2500, C/K 3500, Silverado, Sierra, Cheyenne

Years Covered:

1988, 1989, 1990, 1991, 1992, 1993

Platform Code:

GMT400

👋 Introduction

Positioning:

Essential diagnostic and repair guide for owners and technicians working on the highly popular and robust Chevrolet/GMC C/K pickup and SUV platform of the late 1980s and early 1990s.

Comparison:

Superior to generic repair guides due to its precise, factory-backed specifications and procedures directly applicable to the GMT400 platform, mirroring the content used by dealership professionals.

Features:

Comprehensive, vehicle-specific, dealer-level repair information, detailed wiring diagrams, exploded views, torque specifications, troubleshooting guides.

📋 Manual Details

Coverage Scope:

All models, all repairs A-Z

Estimated Page Count:

1500+

Type:

Factory Service and Repair Manual

Publisher Origin:

Represents content equivalent to Chilton, Haynes, or factory service manuals (FSMs), but typically sourced from OEM or authorized aftermarket publishers specializing in this era.

Language:

English

Format:

Printed Book

📖 Manual Coverage

Powertrain:

Engine mechanical, fuel, ignition, exhaust, cooling, lubrication, clutch, manual transmission, automatic transmission, transfer case (4WD)

Chassis:

Frame, suspension (front/rear), steering, brakes (front/rear disc/drum, ABS), wheels, tires

Electrical:

Battery, charging system, starting system, lighting, instruments, body control modules, HVAC controls, audio system, power accessories, body electrical diagnostics, wiring diagrams

Body:

Body structure, exterior panels, interior trim, doors, windows, seats, HVAC system (components and operation), body sealing

Emissions Control:

Information on emission control devices like EGR, catalytic converters, and evaporative emission control systems.

Maintenance:

Oil change, filter replacement, fluid checks/changes, tune-ups, belt/hose inspection/replacement, brake pad/shoe replacement, tire rotation

Repair:

Engine overhaul, transmission rebuild, suspension component replacement, brake caliper/master cylinder replacement, steering gear repair, electrical component diagnosis and replacement, body panel repair

Diagnostics:

Troubleshooting charts, diagnostic trouble codes (DTCs), wiring diagram interpretation, component testing procedures

Troubleshooting:

Systematic fault finding for engine performance, electrical issues, transmission problems, brake concerns, and HVAC system malfunctions.

Depth:

Vehicle-specific, detailed, from basic maintenance to complete engine and transmission rebuilds, including diagnostic procedures and specifications.

Engine Rebuild:

Complete step-by-step instructions for engine disassembly, inspection, repair, and reassembly, including bearing clearances, ring gaps, and valve seating.

Electrical Diagnostics:

Detailed wiring diagrams are provided for every system, allowing technicians to trace circuits, test components, and diagnose electrical faults effectively.

📊 Manual Specifications

Format Details:

This is a printed publication, not a digital file.

Quality:

High-quality printing with clear diagrams and text, comparable to original dealership manuals.

Binding:

Stapled or perfect bound (typical for workshop manuals).

Paper:

Durable, off-white paper stock, suitable for workshop environments.

⚙️ Engine Specifications

Engine Options:

4.3L V6 (VIN Z, W), 5.0L V8 (VIN H), 5.7L V8 (VIN K), 7.4L V8 (VIN J)

4.3L V6 Hp:

Approx. 160-170 hp (varies by year/tune)

5.0L V8 Hp:

Approx. 175-190 hp (varies by year/tune)

5.7L V8 Hp:

Approx. 210-230 hp (varies by year/tune)

7.4L V8 Hp:

Approx. 230-255 hp (varies by year/tune)

Fuel Delivery Type:

Electronic Fuel Injection (EFI) / Throttle Body Injection (TBI) for earlier models, Central Multi-Port Fuel Injection (CSFI) later in the range.

Fuel Type:

Unleaded gasoline

ECM Details:

ECM (Engine Control Module) calibration for emissions and performance, diagnostic connector available.

Sensor Systems:

Coverage of sensors such as MAP, TPS, ECT, O2, Knock, and Crankshaft Position Sensors (CPS) and their diagnostic procedures.

🔧 Transmission

Standard Transmission Type:

NV3500 5-speed manual (primarily on 1500 series), NP435 4-speed manual (heavy duty).

Automatic Transmission Options:

4L60 4-speed automatic (RWD/4WD), 4L80E 4-speed automatic (heavy duty, 2500/3500).

4Wd Transfer Case:

Manual shift (NP208, NP241) or electronic shift (Autotrac) transfer cases covered for 4WD models.

Atf Type:

Dexron-III Automatic Transmission Fluid (or equivalent).

Manual Transmission Fluid Type:

GL-4 or GL-5 gear oil (specific viscosity varies by transmission model, e.g., 75W-90).

📐 Dimensions

Wheelbase Options:

Various, including 118.0" (Regular Cab), 131.5" (Extended Cab), 153.0" (Crew Cab, some models).

Body Styles:

2WD/4WD Pickup Trucks (Fleetside, Step-side), Chassis Cab, Suburban, Tahoe/Yukon (SUV variants of the platform).

Gvwr Range:

Ranges from approximately 6,000 lbs (C1500) to over 10,000 lbs (C3500HD).

Curb Weight Range:

Varies significantly based on configuration, typically 4,000-6,000 lbs.

🛡️ Safety Features

NHTSA Ratings Era:

As per 1988-1993 era standards, specific NHTSA ratings may not be readily available in a comparable format to modern testing.

ABS Availability:

Anti-lock Braking System (ABS) available on some models, particularly later years and heavier duty trucks.

Seatbelts:

Three-point shoulder belts and lap belts standard, driver-side airbag introduced in later years of the generation (check specific model year).

💡 Technology Features

Audio System:

Factory AM/FM/Cassette stereo systems, with optional CD players in later years. Basic radio controls, speaker configurations vary by trim and cab style.

Cruise Control:

Available as an option on most models, integrated into steering column or dash controls.

Diagnostic Port:

OBD-I diagnostic connector, typically located under the dash or in the engine bay, requires specific breakout boxes for advanced diagnostics.

🔧 Maintenance

Oil Change Interval:

Typically every 3,000-5,000 miles or 3-6 months, depending on driving conditions and oil type used (refer to manual for exact intervals).

Tune Up Interval:

Spark plug replacement recommended around 60,000-100,000 miles, depending on plug type (e.g., platinum).

Transmission Service Interval:

Automatic transmission fluid and filter service recommended every 30,000-60,000 miles. Manual transmission fluid typically lasts much longer.

Engine Oil Specification:

API Service SG or SH, viscosity typically 5W-30 or 10W-30 (refer to specific engine and climate).

Coolant Specification:

Ethylene glycol-based coolant, typically a 50/50 mix with distilled water. GM P/N 1052840 or equivalent.

Brake Fluid Specification:

DOT 3 Brake Fluid (GM P/N 12377976 or equivalent).

Common Wear Items:

Intake manifold gaskets (V8s), rear main seal leaks, HVAC blower motor resistor, fuel pump, catalytic converter, ABS sensor failures (if equipped).

Engine Issues Vortec:

While Vortec heads were introduced late in this generation, early 4.3L V6 engines could suffer from spider injector issues in TBI systems, and later CSFI systems had their own unique problems.

Transmission Issues:

4L60 automatic transmission can develop torque converter clutch (TCC) issues or rear planetary gear failures. Manual transmissions are generally robust.

📚 Vehicle History

Chevrolet Truck Legacy:

Continued Chevrolet's long-standing reputation for building durable and capable trucks, building upon the legacy of the previous C/K generations.

Gmt400 Introduction:

The GMT400 platform marked a significant redesign, featuring a more aerodynamic body, improved interior comfort, and a more refined ride compared to its predecessor.

Subsequent Updates:

Received iterative updates throughout its production run, including minor styling changes, new engine options, and technological enhancements like ABS and airbags.

Production Period:

1988-1998 (GMT400 platform). This manual specifically covers the initial phase of this platform.

Manufacturing Locations:

Primarily assembled in North America (USA, Mexico, Canada).

🏆 Awards & Recognition

Truck Of The Year:

The GMT400 platform was well-regarded for its capabilities and comfort, often featured in 'Truck of the Year' discussions and comparisons during its era.

Consumer Satisfaction:

Generally received positive reviews for durability and work capability, making them enduringly popular in the used market.