Introduction

Restoring a Triumph TR7 or TR8 can be one of the most rewarding projects in the classic car world. These distinctive wedge-shaped sports cars, while controversial when new, have gained significant appreciation among enthusiasts. This comprehensive guide will walk you through every aspect of bringing your TR7 or TR8 back to its former glory.

Before You Start: This guide assumes you have basic mechanical knowledge and access to appropriate tools. Some procedures require professional assistance or specialized equipment.

The TR7 and TR8 share most components, with the main differences being the engine and associated systems. This guide covers both models, noting differences where applicable.

Planning Your Restoration

Initial Assessment

Before diving into your restoration, conduct a thorough assessment of your TR7 or TR8. This evaluation will guide your approach and help establish realistic expectations.

Assessment Tools Needed:

  • Flashlight or inspection light
  • Small magnet (to detect body filler)
  • Basic hand tools
  • Camera for documentation
  • Notebook for taking notes

Key Areas to Inspect:

  1. Body Structure: Check for rust in critical areas including door frames, rear wheel wells, floor pans, and around the rear window.
  2. Engine Condition: Assess compression, oil leaks, and overall mechanical condition.
  3. Electrical Systems: Test all lights, gauges, and electrical components.
  4. Interior: Evaluate seats, dashboard, and trim condition.
  5. Documentation: Verify VIN numbers and gather any maintenance records.
Critical Rust Areas: Pay special attention to the rear suspension mounting points and floor pan integrity. These are safety-critical areas that can be expensive to repair properly.

Budgeting Your Restoration

Triumph restorations can vary widely in cost depending on the car's condition and your desired end result. Here's a breakdown of typical costs:

Category Basic Restoration Concours Restoration Notes
Bodywork & Paint $3,000 - $6,000 $8,000 - $15,000 Varies greatly with rust extent
Engine Rebuild $2,500 - $4,000 $4,000 - $7,000 TR8 V8 typically more expensive
Interior $1,500 - $3,000 $3,000 - $6,000 Convertible tops add $800-1,200
Electrical $500 - $1,500 $1,500 - $3,000 Consider complete rewiring
Miscellaneous $1,000 - $2,000 $2,000 - $4,000 Tools, supplies, unexpected items

Workspace Setup

A proper workspace is crucial for a successful restoration. Ideally, you'll need:

  • Covered Space: A garage or workshop large enough for the car plus workspace around it
  • Good Lighting: Both general and task lighting
  • Power Supply: 110V and 220V outlets for various tools
  • Ventilation: Essential for painting and chemical work
  • Storage: Organized space for parts and tools

Bodywork & Paint

The bodywork phase is often the most time-consuming and expensive part of a TR7/8 restoration. British Leyland's quality control issues mean most cars will need significant attention.

Rust Repair

TR7/8 cars are notorious for rust in specific areas. Addressing these issues properly is crucial for a lasting restoration.

[Image: Common rust areas on TR7/8 body]

Priority Rust Areas:

  1. Rear Wheel Wells: The most common problem area. Often requires patch panels or complete replacement.
  2. Door Frames: Lower door frames and A-pillar bases frequently rust through.
  3. Floor Pans: Check under carpets and seats for rust-through.
  4. Rear Window Area: Water intrusion often causes rust around the rear window frame.
  5. Rocker Panels: Hidden rust can compromise structural integrity.

Rust Repair Tools:

  • Angle grinder with cutting discs
  • Wire brushes and sandpaper
  • Rust converter/neutralizer
  • Welding equipment (MIG recommended)
  • Body filler and application tools
  • Primer and painting supplies

Rust Repair Process:

  1. Cut out all affected metal, going well beyond visible rust
  2. Clean surrounding metal with wire brush and rust converter
  3. Fabricate or purchase replacement panels
  4. Weld in new metal, ensuring proper fit and alignment
  5. Grind welds smooth and apply body filler as needed
  6. Prime all bare metal immediately to prevent further rust
Safety Warning: Welding and grinding create dangerous fumes and sparks. Always use proper ventilation, protective equipment, and fire safety precautions.

Panel Work & Bodywork

After addressing rust issues, focus on achieving smooth, straight panels ready for paint.

Panel Preparation Steps:

  1. Sand all surfaces to remove old paint and rust
  2. Apply body filler to low spots and imperfections
  3. Sand filler smooth, checking with guide coat
  4. Apply primer-surfacer to fill minor imperfections
  5. Sand primer with progressively finer grits (400-800)
  6. Clean panels thoroughly before final paint

Painting Process

A quality paint job requires proper preparation and technique. Consider professional help for base coat/clear coat systems.

Color Matching: Original Triumph paint codes can be found on the VIN plate. Many classic car paint suppliers can match original colors.

Mechanical Systems

Engine Rebuild

Both the TR7's 2.0L four-cylinder and the TR8's 3.5L V8 are generally reliable engines when properly maintained.

TR7 Four-Cylinder Engine

The TR7's engine is related to the Triumph Dolomite Sprint engine and features:

  • SOHC design with timing chain
  • Wet sleeve cylinders
  • Relatively simple carburetion (or fuel injection on later models)

Engine Rebuild Tools:

  • Engine hoist and stand
  • Complete socket and wrench sets
  • Torque wrench (accurate to specification)
  • Cylinder bore gauge
  • Plastigauge for bearing clearances
  • Ring compressor and installation tools

Common TR7 Engine Issues:

  1. Timing Chain Stretch: Replace chain, tensioner, and guides
  2. Head Gasket Failure: Often due to overheating; check head for warpage
  3. Oil Leaks: Replace all seals and gaskets during rebuild
  4. Carburetor Problems: Rebuild or replace Zenith-Stromberg carburetors

TR8 V8 Engine

The TR8's Rover V8 is a proven design originally from Buick:

  • Aluminum block and heads (lightweight)
  • Simple pushrod design
  • Generally more reliable than the four-cylinder
V8 Advantage: The aluminum V8 is actually lighter than the iron four-cylinder, improving the car's balance and performance.

Transmission

Most TR7/8 cars came with either a 4-speed or 5-speed manual transmission. Some later models offered a 3-speed automatic.

Manual Transmission Service:

  1. Drain old gear oil and inspect for metal particles
  2. Remove transmission for thorough inspection
  3. Replace worn synchros and gear sets as needed
  4. Install new seals and gaskets
  5. Refill with proper specification gear oil

Suspension & Steering

The TR7/8 features independent suspension all around with MacPherson struts in front and a complex trailing arm setup in the rear.

Suspension Rebuild Process:

  1. Remove all suspension components for inspection
  2. Replace rubber bushings with polyurethane upgrades
  3. Rebuild or replace shock absorbers/struts
  4. Check ball joints and tie rod ends
  5. Perform wheel alignment after reassembly
Safety Critical: Suspension work affects vehicle safety. Have alignment checked professionally and test drive carefully after any suspension work.

Electrical Systems

British electrical systems have a reputation for issues, but the TR7/8 is actually more reliable than earlier British cars. However, age-related problems are common.

Common Electrical Problems:

  • Ground Connections: Corrosion causes many electrical gremlins
  • Lucas Components: Switches and relays may need replacement
  • Wiring Harness: Consider complete replacement on high-mileage cars
  • Alternator: Upgrade to higher output unit if adding accessories

Electrical System Upgrade:

  1. Install new main wiring harness
  2. Upgrade fuse box to blade-type fuses
  3. Add relays for high-current circuits
  4. Install modern electronic ignition
  5. Consider LED lighting upgrades
[Image: TR7/8 wiring diagram and common electrical components]

Interior Restoration

TR7/8 interiors were well-designed for their era but materials don't age well. Most restorations require significant interior work.

Interior Components:

Seats

  • Reupholster with correct materials and patterns
  • Rebuild seat frames if necessary
  • Replace worn seat adjusters and slides

Dashboard

  • Repair or replace cracked dashboard pad
  • Rebuild gauges or source good used units
  • Replace console trim and switches

Convertible Tops (if applicable)

  1. Remove old top and inspect frame
  2. Repair or replace damaged frame components
  3. Install new top with proper alignment
  4. Adjust top mechanism for smooth operation

Interior Tools:

  • Upholstery tools and heavy-duty sewing machine
  • Plastic trim removal tools
  • Dashboard repair materials
  • Carpet installation tools

Final Assembly

The final assembly phase brings all your hard work together. Take your time and pay attention to details.

Assembly Order:

  1. Install drivetrain (engine and transmission)
  2. Connect exhaust system
  3. Install suspension components
  4. Mount wheels and tires
  5. Complete electrical connections
  6. Install interior components
  7. Add fluids and perform initial start-up
  8. Road test and make adjustments
First Start: Take your time with the first start-up. Check for leaks, unusual noises, and proper operation of all systems before driving.

Break-in Period

After a complete restoration, follow proper break-in procedures:

  • Keep RPMs below 3000 for first 500 miles
  • Vary engine load and speed
  • Change oil at 500 miles and 1500 miles
  • Check all fluid levels regularly
  • Monitor for any unusual noises or behavior

Resources & Suppliers

Parts Suppliers

  • Rimmer Bros - Comprehensive TR7/8 parts catalog
  • British Parts Northwest - Quality reproduction parts
  • Racetorations - Performance and restoration parts
  • Moss Motors - General British car parts

Technical Resources

  • TR7/8 Club Forums - Active online communities
  • Bentley Service Manual - Essential technical reference
  • Triumph Wedge Owners Association - Specialized club
  • Classic Car Magazines - Restoration articles and tips

Professional Services

Consider professional help for:

  • Machine shop work (engine rebuilding)
  • Paint and bodywork
  • Electrical troubleshooting
  • Upholstery work
  • Wheel alignment and suspension setup
Documentation: Keep detailed records of your restoration including photos, receipts, and part numbers. This documentation adds value and helps with future maintenance.