🏷️ Basic Information

Make:

Jaguar

Model:

420

Model Code:

XJ6 Series 1 (platform shared, visually distinct)

Production Years:

1966-1968

Chassis Prefix:

420

👋 Introduction

Segment:

Luxury Saloon / Executive Car

Key Competitors:

Rover P5B, Rover P6, Mercedes-Benz W108/W109, BMW E3

Styling:

Elegant 'Sovereign' styling, derived from the Jaguar XJ6 but with a more formal grille and quad headlights.

Performance Credentials:

Blend of Jaguar's performance heritage with increased luxury and comfort for the executive market.

Audience:

Senior executives, discerning drivers seeking a balance of performance, luxury, and classic British style.

📋 Manual Details

Documentation Type:

Service Repair Manual and Parts Catalogue

Estimated Page Count:

300-400 pages (typical for combined manuals of this era)

Manual Format:

Combined Service Manual and Parts List/Catalogue

Language:

English

Format Type:

Print Replica / PDF (digital versions are common for sales)

📖 Manual Coverage

Powertrain:

Engine (XK Series 4.2L I6), Fuel System, Ignition System, Cooling System, Exhaust System

Transmission:

Manual (Moss Gearbox), Automatic (BorgWarner Model 8)

Chassis:

Front Suspension (Double Wishbone, Coil Springs, Anti-Roll Bar), Rear Suspension (IRS - Independent Rear Suspension, Semi-Trailing Arms, Coil Springs), Steering System (Power Assisted Steering), Brakes (Dunlop Disc Brakes - Front and Rear)

Electrical:

Starting System, Charging System (Generator/Alternator), Lighting, Instrumentation, Wipers, Horn, Radio (Optional)

Bodywork:

Body Shell, Doors, Hood, Trunk Lid, Bumpers, Glass, Seats, Interior Trim

Routine Maintenance:

Oil Changes, Filter Replacements, Spark Plug Service, Lubrication Points, Air Filter Service

Engine Repair:

Engine Overhaul, Piston/Ring Replacement, Valve Grinding, Bearing Replacement, Timing Chain Service

Transmission Repair:

Manual Gearbox Overhaul, Automatic Transmission Service and Repair (adjustments, seal replacement)

Brake System Repair:

Brake Pad/Shoe Replacement, Disc/Drum Machining, Caliper Overhaul, Fluid Bleeding

Electrical Troubleshooting:

Wiring Diagrams, Component Testing, Fault Diagnosis

Suspension And Steering Repair:

Bushings, Ball Joints, Shock Absorber Replacement, Steering Rack/Box Service

Fuel System Repair:

Carburetor Overhaul (SU HS8/HD8), Fuel Pump Service, Fuel Line Replacement

Ignition System Repair:

Distributor Service, Coil Replacement, HT Lead Replacement

Depth Level:

Comprehensive (from basic maintenance to full engine and transmission rebuilds, with detailed part identification)

Part Identification:

Illustrated parts breakdown with part numbers for most components

📊 Manual Specifications

Digital Format:

PDF (Searchable Text, High Resolution Images)

Print Quality:

High-resolution scans suitable for professional printing

Binding Type:

N/A (for digital format), Typically Spiral or Perfect Bound (for printed versions)

Paper Type:

N/A (for digital format), Glossy/Matte Paper (for printed versions)

⚙️ Engine Specifications

Engine Type:

DOHC Inline 6-Cylinder (Jaguar XK Series)

Displacement:

4.2 Liters (4235 cc)

Bore X Stroke:

92.08 mm x 106.00 mm

Compression Ratio:

8.0:1 or 8.5:1 (depending on market/spec)

Horsepower Bhp:

Approx. 245 bhp @ 5500 rpm

Torque Lb Ft:

Approx. 283 lb-ft @ 3500 rpm

Carburetion:

Twin SU HD8 or HS8 Constant Velocity Carburetors

Fuel Type:

Premium Unleaded Gasoline (Octane rating dependent on market, historically 95-98 RON)

Cooling Type:

Water Cooled

Oil Capacity Quarts:

7.5 US Quarts (with filter)

🔧 Transmission

Type:

3-Speed Automatic (BorgWarner Model 8)

Type:

4-Speed Manual (Moss Gearbox, with Overdrive on 4th gear)

Automatic Features:

Column or floor shift selection, smooth engagement.

Manual Features:

Synchromesh on all gears, overdrive for highway cruising.

📐 Dimensions

Length Mm:

4905 mm (193.1 in)

Width Mm:

1734 mm (68.3 in)

Height Mm:

1372 mm (54.0 in)

Wheelbase Mm:

2728 mm (107.4 in)

Front Track Mm:

1359 mm (53.5 in)

Rear Track Mm:

1334 mm (52.5 in)

Curb Weight Kg:

Approx. 1600-1700 kg (3527-3748 lbs)

Gross Vehicle Weight Kg:

Approx. 2000 kg (4409 lbs)

🛡️ Safety Features

Crash Test Era:

Pre-modern crash testing standards; focus on structural integrity and passenger protection for the era.

Braking System:

Dunlop disc brakes on all four wheels, servo-assisted.

Steering System:

Power assisted recirculating ball steering.

Seatbelts:

Front seatbelts standard, rear optional depending on market.

Body Construction:

Monocoque chassis construction providing good rigidity for its time.

💡 Technology Features

Audio System:

Original Lucas or Motorola Radios (optional, often AM/FM)

Power Steering:

Standard power-assisted steering for reduced driver effort.

N A:

No modern electronic connectivity features typical of the era.

🔧 Maintenance

Oil Change Interval:

Every 3,000 miles or 6 months (typical for the era).

Tune Up Interval:

Every 6,000-12,000 miles (depending on specific items like ignition points, plugs).

Engine Oil Viscosity:

SAE 20W/50 or 10W/30 (depending on climate, consult manual for precise recommendation).

Coolant Type:

Ethylene Glycol based antifreeze mixture (50/50 with water).

Brake Fluid Type:

DOT 3 or DOT 4 Hydraulic Brake Fluid (check manual for exact specification).

Transmission Fluid Auto:

Dexron-III (or equivalent for BorgWarner Model 8).

Transmission Fluid Manual:

EP 90 Gear Oil.

Power Steering Fluid:

Type-A Automatic Transmission Fluid or specific power steering fluid as per manual.

Rust And Corrosion:

Common issue on classic cars; sills, wheel arches, and floor pans are typical areas.

Engine Oil Leaks:

Gaskets (rocker cover, sump) and oil seals can degrade over time.

Carburetor Synchronization:

SU carburetors require regular adjustment for optimal performance and fuel economy.

Irs Bushings:

Wear in the rubber bushings for the independent rear suspension can lead to noise and imprecise handling.

Electrical Gremlins:

Ageing wiring looms and connections can cause intermittent faults.

Oil Filter:

Examples: Fram PH2, equivalent Jaguar parts.

Spark Plugs:

Examples: NGK BPR5ES, Champion N12YC.

📚 Vehicle History

Jaguar Legacy:

Jaguar's reputation for building powerful, elegant, and successful sports and luxury cars since the 1930s.

Predecessors:

Drew heavily from the Mk II Jaguar saloon and the platform of the Jaguar XJ6 Series 1.

Distinction From Xj6:

Designed to fill a gap in the Jaguar lineup, offering a more traditional Jaguar grille and styling compared to the XJ6.

Manufacturing Location:

Coventry, England

Production Volume:

Relatively limited production run compared to other Jaguar saloons, contributing to its collector status.

🏆 Awards & Recognition

Classic Car Status:

Recognized as a desirable classic Jaguar, appreciated for its blend of performance and luxury.

Historical Reviews:

Praised by contemporary automotive press for its smooth ride, powerful engine, and refined interior.