🏷️ Basic Information

Make:

Harley-Davidson

Model:

45 SV & Servi-Car

Years Covered:

1940-1958

Model Codes:

U, UL, ULH, WL, WLA, WLD, G, GE, GCS

👋 Introduction

Market Position:

Essential resource for owners and restorers of vintage Harley-Davidson flathead motorcycles.

Competitive Analysis:

This manual consolidates information for the iconic 45 cubic inch (750cc) flathead V-twin engine, covering both civilian and military variants, along with the unique Servi-Car model, offering a singular source for a wide range of related vehicles.

Key Features:

Detailed diagrams, step-by-step repair procedures, troubleshooting tips, and specifications for a broad range of Harley-Davidson models from the late 1940s and 1950s.

📋 Manual Details

Language:

English

Format:

Service/Repair Manual

Page Count:

300+

Manual Type:

Comprehensive Service and Repair Manual

📖 Manual Coverage

Engine Overhaul:

Complete disassembly, inspection, reassembly, tuning of EL, F, FL, and UL series engines.

Transmission:

Service and repair of 3-speed and 4-speed constant mesh transmissions.

Electrical System:

Wiring diagrams, ignition system service (magneto and battery ignition), lighting, charging systems.

Fuel System:

Carburetor service and tuning (Linkert M-series), fuel tank and line maintenance.

Suspension:

Front fork service (leading link, springer), rear suspension components and maintenance.

Braking System:

Drum brake service, adjustment, and relining procedures.

Frame And Bodywork:

Frame inspection, alignment, body panel repair, fender mounting.

Servi Car Specifics:

Detailed instructions for Servi-Car models, including drivetrain, cargo bed, and unique components.

Routine Maintenance:

Oil changes, filter replacement, spark plug service, chain adjustment, lubrication points.

Engine Rebuild:

Piston replacement, ring installation, valve grinding, crankshaft and connecting rod service.

Transmission Rebuild:

Gear inspection, bearing replacement, shift mechanism repair.

Carburetor Tuning:

Detailed steps for Linkert M-series carburetor adjustment for optimal performance.

Ignition Timing:

Methods for setting ignition timing on magneto and battery systems.

Wheel Bearing Service:

Inspection, repacking, and replacement of wheel bearings.

Troubleshooting Guide:

Diagnostic procedures for common starting, running, and electrical issues.

Depth:

Comprehensive from basic maintenance to full engine and transmission overhauls, including electrical troubleshooting.

📊 Manual Specifications

File Format:

Digital (likely PDF)

Print Quality:

High-resolution scans of original factory manuals, suitable for printing.

Binding Type:

N/A (Digital Format)

Paper Type:

N/A (Digital Format)

⚙️ Engine Specifications

Engine Type:

45 cubic inch (750cc) OHV (Overhead Valve) Flathead V-twin

Bore X Stroke:

3.00 in x 3.125 in (76.2 mm x 79.4 mm)

Compression Ratio:

Varies by model and year, typically 5.0:1 to 6.5:1

Engine Variants Covered:

EL (61ci, but manual likely covers overlap or related tech), F, FL, UL, ULH (74ci), WLA (Military), WLD (Police), GE (Servi-Car).

Horsepower:

Approximately 23-30 HP depending on model and tuning

Torque:

Approximately 35-40 ft-lbs

Carburetor:

Linkert M-series (M-3, M-5, M-6, M-74, M-88, etc.)

Fuel Type:

Gasoline (octane rating appropriate for era, typically leaded)

🔧 Transmission

Type:

3-speed or 4-speed constant mesh, foot shift, hand clutch (initially), later foot clutch with foot shift.

Optional Types:

4-speed transmissions became more common in later years.

Clutch Type:

Dry, multi-plate clutch (initially hand-operated, later foot-operated).

Drive Type:

Chain drive (primary drive from engine to transmission, secondary drive from transmission to rear wheel).

Final Drive:

Chain drive

📐 Dimensions

Wheelbase:

Varies by model, typically 57-60 inches

Ground Clearance:

Approximately 5-6 inches

Dry Weight:

Approximately 400-550 lbs depending on model and equipment.

Gross Vehicle Weight Rating:

Not typically specified in the same way as modern vehicles, but capacity for rider, passenger, and cargo.

🛡️ Safety Features

Safety Ratings:

N/A (Pre-modern safety rating era)

Active Features:

Drum brakes, basic lighting (headlight, taillight).

Passive Features:

Robust steel frame construction.

💡 Technology Features

Infotainment System:

N/A (Basic instrumentation: speedometer, ammeter, oil pressure gauge on some models).

🔧 Maintenance

Oil Change Interval:

Every 1,000-2,000 miles or annually, depending on usage and oil type.

Spark Plug Replacement:

Every 5,000-10,000 miles, or as needed based on condition.

Transmission Oil Change:

Every 5,000-10,000 miles or annually.

Chain Lubrication Adjustment:

Lubricate every 500 miles, adjust as needed to maintain proper tension.

Engine Oil:

SAE 50 or SAE 60 monograde motor oil (e.g., HD 360, or compatible vintage oil with ZDDP additive for flat tappets).

Transmission Oil:

Harley-Davidson Transmission Oil or equivalent (e.g., SAE 80W-90 gear oil, though specific vintage recommendations may differ).

Primary Chaincase Oil:

Harley-Davidson Primary Chaincase Oil or SAE 50 motor oil.

Brake Fluid:

N/A (Mechanical drum brakes, no hydraulic fluid required)

Known Issues:

Oil leaks (especially from engine case seals and transmission), carburetor flooding or stalling (Linkert M-series sensitivity to tuning), electrical component reliability (points, condensers, regulators), weak ignition spark at higher RPMs, drum brake performance limitations.

Common Repairs:

Seal replacement, carburetor rebuilding, ignition system overhaul, brake shoe relining or replacement.

📚 Vehicle History

Brand Heritage:

Harley-Davidson, founded in 1903, has a long history of producing reliable and powerful motorcycles, particularly known for its V-twin engines and military applications.

Model Evolution:

The 45 cubic inch flathead engine was a cornerstone of Harley-Davidson's lineup for decades, evolving from earlier designs into reliable workhorses. The WLA model was famously produced in large numbers for the US military during WWII. The Servi-Car model, introduced in 1932, provided a stable three-wheeled platform for commercial use, becoming a common sight in delivery services.

Production Period:

The 45ci flathead engine was in production from the 1930s through the early 1970s. The specific models covered by this manual (1940-1958) represent a significant portion of their service life and popular use.

Key Variants:

WL (Civilian), WLA (Military), WLDR (Race), Servi-Car (G series).

🏆 Awards & Recognition

Recognitions:

These models are highly regarded within the vintage motorcycle community for their historical significance, iconic design, and the enduring legacy of the flathead engine.