Interior Trim and Console - GM Square Body Trucks (1973-1987)

Overview

The interior trim and console components of GM Square Body trucks encompass all decorative and functional interior elements including door panels, dash trim, center consoles, and various interior accent pieces. These components define the cabin's appearance and functionality while housing critical controls and providing storage solutions.

Square Body interiors varied significantly across model years and trim levels, from basic work truck configurations with minimal trim to fully-loaded Silverado and Scottsdale packages featuring woodgrain accents, upgraded door panels, and floor-mounted consoles. Understanding these variations is crucial for proper restoration, replacement, or upgrading of interior components.

The interior trim system includes:
- Door panels and trim pieces
- Dashboard trim and bezels
- Center consoles (floor and mini)
- Pillar trim and headliner moldings
- Kick panels and floor trim
- Interior accent pieces and emblems

Common Issues

Door Panel Problems

• Sagging door panels: Caused by deteriorated backing board and failed mounting clips
• Cracked vinyl/plastic: UV damage and age cause brittle, cracked surfaces
• Missing or broken armrests: High-wear components that frequently crack or detach
• Failed door panel clips: Brittle plastic clips break, causing panels to rattle or fall off

Console Issues

• Cracked console lids: Hinge stress and UV exposure cause lid cracking
• Broken mounting brackets: Console mounting points crack or break loose
• Missing or damaged trim pieces: Small trim pieces are easily lost during disassembly
• Worn console hinges: Spring-loaded hinges weaken over time

Dashboard Trim Problems

• Warped or cracked bezels: Heat and UV damage cause instrument cluster and radio bezels to warp
• Missing trim screws: Specialized trim screws are often lost or stripped
• Faded woodgrain trim: Adhesive-backed woodgrain peels or fades with age
• Broken mounting tabs: Plastic trim pieces develop stress cracks at mounting points

Parts & Materials Needed

Tools Required

• Phillips head screwdrivers (various sizes)
• Flat blade screwdrivers (for prying clips)
• Door panel removal tools or plastic pry bars
• Trim removal tools (plastic wedges)
• Socket set (7mm, 8mm, 10mm common)
• Needle-nose pliers
• Heat gun (for vinyl work)
• Adhesive scraper

Common Replacement Parts

Door Panels (1973-1980)

LMC Truck:
- Basic door panels: 34-1436 (left), 34-1437 (right)
- Deluxe door panels: 34-1438 (left), 34-1439 (right)
- Door panel clips: 34-1445 (set of 10)
- Armrest pads: 34-1441

Door Panels (1981-1987)

LMC Truck:
- Base door panels: 34-1456 (left), 34-1457 (right)
- Custom/Silverado panels: 34-1458 (left), 34-1459 (right)
- Door panel clips: 34-1465 (updated design)

Center Console Components

Classic Industries:
- Complete floor console (1973-1980): INT1040
- Complete floor console (1981-1987): INT1041
- Console lid: INT1042
- Console mounting brackets: INT1043
- Mini console (column shift): INT1045

Dashboard Trim

LMC Truck:
- Instrument bezel (1973-1980): 34-1301
- Instrument bezel (1981-1987): 34-1302
- Radio bezel: 34-1305
- A/C control bezel: 34-1306
- Woodgrain trim kit: 34-1310

Materials and Supplies

• 3M Super 77 spray adhesive
• SEM plastic prep and adhesion promoter
• Interior vinyl cleaner/conditioner
• Plastic welding rods (for crack repair)
• Foam backing material (1/4" and 1/2" thickness)
• Trim adhesive tape (3M VHB)

Step-by-Step Guide

Door Panel Removal and Installation

Removal (1973-1980)

1. Remove window crank handle
   - Use door handle removal tool or wrap shop rag around base
   - Push in and rotate counterclockwise to release retaining clip

2. Remove door handle escutcheon
   - Remove two Phillips screws behind handle
   - Carefully pull escutcheon away from door

3. Remove armrest
   - Locate two screws in armrest cup
   - Remove screws and lift armrest up and out

4. Remove door panel clips
   - Starting at bottom, carefully pry panel away from door
   - Work around perimeter, releasing plastic clips
   - Lift panel up and out to clear door lock rod

Installation

1. Inspect and replace clips
   - Check all mounting clips for cracks or damage
   - Replace any broken clips with new parts

2. Position panel
   - Align panel with door frame
   - Ensure door lock rod passes through proper opening

3. Secure panel
   - Press firmly around perimeter to engage clips
   - Install armrest with original screws
   - Install door handle escutcheon
   - Install window crank handle

Center Console Installation

Floor Console (1973-1987)

1. Prepare mounting points
   - Remove seats if necessary for access
   - Clean floor area thoroughly
   - Locate factory mounting holes or drill new ones per template

2. Install mounting brackets
   Torque specifications: - Floor mounting bolts: 15 ft-lbs - Bracket to console: 8 ft-lbs

3. Route wiring (if equipped with console lights)
   - Connect power wire to fuse block (10A fuse)
   - Route ground wire to nearby body ground

4. Install console assembly
   - Position console over mounting brackets
   - Secure with provided bolts
   - Test all functions before final assembly

Dashboard Trim Installation

Instrument Cluster Bezel

1. Remove steering wheel (if necessary for clearance)

2. Remove existing bezel
   - Locate retaining screws (typically 4-6 screws)
   - Carefully pull bezel away from dash

3. Install new bezel
   - Ensure proper alignment with instrument cluster
   - Secure with original screws (do not overtighten)
   - Verify all warning lights are visible

Year/Model Differences

Early vs. Late Design Changes

1973-1980 Characteristics

• Door panels: Horizontal ribbed design with integrated armrests
• Console: Larger floor console with more angular design
• Dashboard: Chrome trim pieces standard, woodgrain optional
• Mounting: Different clip designs and mounting points

1981-1987 Updates

• Door panels: Smoother design with separate armrest components
• Console: Revised styling with rounded edges
• Dashboard: More integrated plastic trim pieces
• Color options: Expanded interior color choices

Model-Specific Variations

C10/C20 Regular Cab

• Standard equipment: Basic door panels, column-mounted shifter
• Console options: Mini console available with column shift
• Trim levels: Work Truck, Custom, Silverado packages

K10/K20 4WD Models

• Transfer case: Floor console modified for transfer case shifter
• Door panels: Identical to 2WD models
• Special equipment: Additional gauge packages more common

K5 Blazer

• Rear panels: Additional rear door panels (1973-1991)
• Console: Modified for shorter wheelbase
• Cargo area: Special rear trim pieces and panels

Suburban

• Extended panels: Longer door panels for extended doors
• Third row: Additional trim pieces for rear seating area
• Cargo area: Extensive rear trim and panel systems

Trim Level Differences

Base/Work Truck

• Plain vinyl door panels
• No console (column shift only)
• Minimal dashboard trim
• Basic interior colors (typically black or blue)

Custom/Scottsdale

• Upgraded door panels with cloth inserts
• Optional floor console
• Chrome dashboard accents
• Expanded color options

Silverado (1975-1987)

• Premium door panels with carpeted lower sections
• Standard floor console
• Woodgrain dashboard trim
• Premium interior colors and materials

Tips & Best Practices

Restoration Tips

• Document before disassembly: Take photos of all connections and mounting points
• Save all hardware: Original screws and clips are often difficult to replace
• Work in clean environment: Interior components show dirt and scratches easily
• Test fit before final assembly: Ensure proper alignment before securing permanently

Material Selection

• OEM vs. Aftermarket: OEM parts offer best fit but aftermarket provides color options
• Grain matching: Ensure all vinyl/plastic pieces have matching grain patterns
• Color accuracy: Interior colors fade differently; consider complete replacement for best match

Installation Best Practices

• Temperature considerations: Install vinyl components at room temperature (70°F+)
• Adhesive curing: Allow 24 hours cure time for adhesive-mounted components
• Hardware torque: Use proper torque specifications to avoid cracking plastic
• Clip orientation: Ensure door panel clips are properly oriented before installation

Common Mistakes to Avoid

• Forcing clips: Broken clips are expensive to replace; use proper removal tools
• Over-tightening screws: Plastic trim pieces crack easily with excessive torque
• Mixing years: Early and late components are not always interchangeable
• Ignoring backing boards: Door panel backing boards must be solid for proper mounting

Troubleshooting

Door Panel Issues

Panel Won't Stay Attached

Symptoms: Panel falls away from door or rattles
Diagnosis:
- Inspect door panel clips for damage
- Check door frame clip receptacles for damage
- Verify correct clip type for year/model

Solutions:
- Replace broken clips with correct part numbers
- Repair damaged door frame receptacles with plastic welding
- Ensure clips are fully engaged during installation

Sagging Door Panels

Symptoms: Panel sags at bottom, pulls away from door frame
Diagnosis:
- Remove panel and inspect backing board
- Check for moisture damage or deterioration
- Examine clip mounting points in backing board

Solutions:
- Replace backing board if damaged
- Reinforce mounting points with additional material
- Consider upgrading to later-style panels with improved backing

Console Problems

Console Lid Won't Stay Closed

Symptoms: Lid pops open or won't latch properly
Diagnosis:
- Inspect latch mechanism for wear or damage
- Check lid alignment with console base
- Examine hinge operation

Solutions:
- Adjust latch mechanism if possible
- Replace worn latch components
- Realign lid with proper shimming

Broken Console Mounting

Symptoms: Console moves or shifts during use
Diagnosis:
- Check floor mounting points for damage
- Inspect console mounting brackets
- Verify all mounting hardware is present

Solutions:
- Repair or reinforce floor mounting points
- Replace damaged mounting brackets
- Use thread locker on mounting bolts

Dashboard Trim Issues

Warped or Cracked Bezels

Symptoms: Visible warping, cracks, or poor fit around instruments
Diagnosis:
- Remove bezel and inspect for heat damage
- Check mounting points for stress cracks
- Evaluate feasibility of repair vs. replacement

Solutions:
- Minor warping: Carefully heat and reform using controlled heat
- Stress cracks: Plastic weld from behind, sand and refinish
- Severe damage: Replace with new or good used bezel

Loose or Missing Trim Pieces

Symptoms: Trim pieces rattle, fall off, or are missing
Diagnosis:
- Identify specific trim piece and mounting method
- Check for broken mounting tabs or clips
- Verify correct part number for year/model

Solutions:
- Source correct replacement parts
- Repair mounting tabs with plastic welding if possible
- Use appropriate adhesive for non-mechanical mounting

Color Matching Issues

Faded or Mismatched Components

Symptoms: Interior components don't match in color or texture
Diagnosis:
- Compare components in natural light
- Identify which pieces are original vs. replacement
- Determine if fading is uniform or localized

Solutions:
- Minor fading: Use vinyl/plastic restoration products
- Significant mismatch: Replace entire component sets for uniformity
- Custom applications: Consider professional dying or reupholstering

This comprehensive guide covers the essential aspects of Square Body interior trim and console systems, providing the technical detail and practical guidance needed for successful restoration or repair projects.