🏷️ Basic Information

Make:

Harley-Davidson

Model:

Dyna

Year:

2004

Platform:

Dyna

Vin Designator:

1HD

👋 Introduction

Positioning:

The 2004 Harley-Davidson Dyna models represented a refined iteration of the classic American cruiser, appealing to riders seeking authentic V-twin performance and a customizable platform. This manual targets owners and independent mechanics who prioritize DIY maintenance and repair.

Competitors:

Competed with other American V-twin cruisers from brands like Indian, and some Japanese cruisers with similar engine configurations and rider focus.

Features:

The 2004 Dyna lineup featured the robust Twin Cam 88 engine, a hallmark of Harley-Davidson's cruiser experience. This manual is crucial for maintaining and repairing these machines, which are known for their distinctive styling, sound, and rider engagement.

📋 Manual Details

Models Covered:

All Dyna models (e.g., Super Glide, Low Rider, Wide Glide, Street Bob, Fat Bob, Sportster - *Note: Sportster is a separate family, manual likely covers Dyna variants ONLY*)

Engine Variants Covered:

All applicable 2004 Dyna engine options (primarily Twin Cam 88, potentially Twin Cam 88B for rigid mount)

Trim Levels Covered:

All trim levels within the 2004 Dyna range

Estimated Page Count:

600-800+ (Typical for comprehensive workshop manuals)

Type:

Workshop Repair Service Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine:

Engine assembly, disassembly, inspection, tuning, top-end components (cylinders, pistons, heads), bottom-end components (crankshaft, connecting rods), valve train, lubrication system, cooling system (air-cooled), fuel injection/carburetion system, ignition system, exhaust system.

Transmission:

5-speed transmission (e.g., Cruise Drive), clutch operation and service, gear shift mechanism, primary drive system, transmission lubrication.

Electrical:

Battery and charging system (alternator, regulator), starting system, ignition system (coil, spark plugs, module), lighting (headlight, taillight, turn signals), instrumentation, wiring diagrams, switches, sensors, EFI control unit.

Chassis:

Frame, front forks and suspension, rear shock absorbers and suspension, steering system, wheel bearings, swingarm, brake system (front and rear), wheel and tire service.

Bodywork:

Fuel tank, fenders, seat, handlebars, controls, footpegs, mirrors, fairings/covers (if applicable to specific models), basic bodywork repair and maintenance.

Maintenance:

Scheduled maintenance, oil changes, filter replacements, chain/belt adjustment, brake pad replacement, tire pressure checks, battery maintenance.

Troubleshooting:

Diagnostic procedures for common issues, fault code interpretation (if applicable), electrical system diagnostics, engine performance issues, braking problems.

Repair:

Step-by-step instructions for component removal, installation, overhaul, and adjustment for all major systems.

Specifications:

Torque specifications for fasteners, fluid capacities, electrical component specifications, engine clearances, wear limits.

Depth:

Comprehensive, covering from basic rider maintenance to full engine rebuilds, transmission overhauls, and electrical system diagnostics.

📊 Manual Specifications

PDF Quality:

High-resolution, typically scanned from original factory publications. Text should be searchable if OCR'd.

Printability:

Printable, allowing users to print specific sections or the entire manual.

Binding:

Not Applicable (Digital PDF)

Paper:

Not Applicable (Digital PDF)

⚙️ Engine Specifications

Engine Type:

Air-cooled, 45-degree V-twin, pushrod actuated overhead valves

Displacement:

88 cubic inches (1450cc)

Bore X Stroke:

3.75 in. x 4.00 in. (95.25 mm x 101.6 mm)

Compression Ratio:

Approximately 8.8:1 (varies slightly by sub-model/carburetor)

Engine Mounting:

Rubber-isolated (for most Dyna models) or rigid mount (e.g., FXDX, FXDXT)

Horsepower Estimate:

Approx. 65-70 HP @ 5500 RPM (at crank, stock tuning)

Torque Estimate:

Approx. 78-82 ft-lbs @ 3500 RPM (at crank, stock tuning)

Fuel Delivery:

Carburetor (e.g., Keihin CV 40mm) or Electronic Fuel Injection (EFI) depending on specific model/region.

Fuel Type:

Unleaded gasoline, minimum 91 octane (RON + MON)/91 AKI recommended.

Ignition Type:

Electronic ignition module, single fire coil.

Oil Capacity W Filter:

Approximately 3.0 US quarts (2.8 L) for Twin Cam 88B (rigid mount) and 3.5 US quarts (3.3 L) for Twin Cam 88 (rubber mount).

Oil Type Recommendation:

Harley-Davidson Genuine V-Twin Oil or equivalent API SG, JASO MA approved SAE 20W-50 or 10W-40 (depending on ambient temperature, consult manual for specifics).

🔧 Transmission

Transmission Type:

5-speed constant mesh, helical cut gears

Primary Drive:

Duplex chain drive, wet clutch

Final Drive:

Belt drive (typically 132-tooth, 1-inch pitch, 13mm belt for most 2004 Dyna models)

Clutch Type:

Wet, multi-plate, diaphragm spring

Transmission Oil Capacity:

Approximately 1.0 US quart (0.95 L)

Transmission Oil Type Recommendation:

Harley-Davidson Genuine Transmission Oil or SAE 75W-90 (API GL-5) or SAE 65W-75 (API GL-4) gear lubricant.

📐 Dimensions

Wheelbase Estimate:

Approx. 62.5 - 64.5 inches (1588 - 1638 mm) depending on model

Dry Weight Estimate:

Approx. 600 - 630 lbs (272 - 286 kg) depending on model

Gross Vehicle Weight Rating Estimate:

Approx. 1000 lbs (454 kg)

Fuel Capacity:

Approx. 4.0 - 5.0 US gallons (15.1 - 18.9 L) depending on model (e.g., 4.0 gal for Low Rider, 5.0 gal for Wide Glide)

🛡️ Safety Features

Crash Test Ratings:

Not applicable in the same way as passenger vehicles. Motorcycle safety is focused on handling, braking, and rider aids.

Braking System:

Dual-piston caliper front brake, dual-piston caliper rear brake. (ABS was not standard on most 2004 Dyna models, but might have been an option on certain high-end variants like FXDXT).

Lighting:

Halogen headlight, incandescent tail/brake lights, incandescent front/rear turn signals.

Frame Construction:

Steel, double-cradle frame designed for stability and rigidity.

Suspension:

Telescopic front forks (e.g., 41mm Showa or similar), dual rear shock absorbers with adjustable pre-load.

💡 Technology Features

Infotainment System:

Base models typically had minimal or no integrated infotainment. Handlebar-mounted radio/CD players and speakers were often aftermarket or dealer-installed options.

ABS:

Anti-lock Braking System (ABS) was generally an optional feature, not standard across all 2004 Dyna models.

Connectivity Features:

No integrated smartphone connectivity or advanced telematics. Focus is on core motorcycle functionality.

🔧 Maintenance

Initial Service:

First service typically at 1,000 miles (1600 km) - includes engine oil change, primary chain case oil change, transmission oil change, chassis lubrication, and inspection of all critical components.

Regular Oil Change:

Every 5,000 miles (8000 km) or annually, whichever comes first. Primary and transmission oil changes recommended at the same interval, or as specified.

Air Filter Replacement:

Inspect every 5,000 miles (8000 km), replace as needed or based on operating conditions.

Spark Plug Replacement:

Typically at 10,000 - 15,000 miles (16,000 - 24,000 km).

Belt Drive Tension:

Check and adjust belt tension every 5,000 miles (8000 km) or as per manual specification.

Engine Oil:

Harley-Davidson Genuine V-Twin Oil or API SG/SH/SJ/SL, JASO MA approved SAE 20W-50 or 10W-40 (refer to manual for ambient temp charts).

Primary Chain Case Oil:

Harley-Davidson Genuine Primary Chain Case Lubricant or Formula+ or equivalent SAE 85W-140 (API GL-5).

Transmission Oil:

Harley-Davidson Genuine Transmission Oil or SAE 75W-90 (API GL-5) or SAE 65W-75 (API GL-4) gear lubricant.

Brake Fluid:

DOT 4 Heavy Duty (for clutch and brake systems, consult manual for specific caliper compatibility).

Cam Chain Tensioner:

Early Twin Cam engines (including some 2004 models) used plastic hydraulic cam chain tensioners that could wear out, leading to noise and potential engine damage. Upgrade to improved tensioners is a common modification.

Exhaust Leaks:

Exhaust header pipe leaks at the cylinder head can occur due to vibration or faulty gaskets.

Wheel Bearings:

While generally durable, wheel bearings can require inspection and replacement over time, especially with high mileage or exposure to water/dirt.

Fuel System Reliability:

EFI systems can be complex; issues might include sensor failures or fuel pump issues. Carbureted models require periodic adjustment and cleaning.

📚 Vehicle History

Heritage:

Harley-Davidson, founded in 1903, is an iconic American motorcycle manufacturer with a rich history of building V-twin cruisers known for their distinctive styling, sound, and build quality.

Evolution:

The Dyna platform was introduced in 1991 as a modern iteration of Harley's cruiser line, evolving from the FXR platform. The 2004 models represent a significant step with the widespread adoption of the Twin Cam 88 engine and improvements in chassis dynamics and rider comfort.

Manufacturing Location:

United States (primarily York, Pennsylvania and Milwaukee, Wisconsin)

Production Years:

Dyna platform produced from 1991 to 2017. 2004 is within the second generation of the Dyna family, post-introduction of the Twin Cam engine.

🏆 Awards & Recognition

Industry Awards:

Harley-Davidson motorcycles, in general, have received numerous accolades over the years for their design, engineering, and cultural impact. Specific awards for the 2004 Dyna models are less commonly cited than the overall brand recognition.

Consumer Ratings:

Highly rated by riders for their classic styling, V-twin character, and customization potential. Reliability can be a point of discussion, often dependent on maintenance and specific model year revisions.