Honda GL 1000 Gold Wing 1975–1979 Shop Manual (P/N HC 72459)

Honda’s GL 1000 Gold Wing Shop Manual (P/N HC 72459), in its July 1978 U.S. printing, covers 1975–1979 models. Its 18 sections address maintenance schedules, troubleshooting, adjustments, and mechanical and electrical repair.

Printable PDF and Wiring-Diagram Detail

Search, navigation and small labels: PDF text search and embedded bookmarks are not available. The section contents pages provide navigation references. Small wiring-diagram labels require magnification; some wire-color codes in the 1975–1977 diagram remain soft.

Supplied as a single printable, English-language 327-page PDF, including the original cover and table-of-contents page.

Flat-Four Engine, Drivetrain and Electrical Service

These highlights are a selection of the manual’s contents, rather than a complete contents list. Other topics include fuel-tank removal and side-stand inspection.

• Engine repair: Engine removal and installation, timing-belt service, cylinder-head disassembly, valve-guide replacement, valve-seat grinding, and crankshaft and bearing inspection.

• Tune-up and fuel: Step-by-step carburetor synchronization and dynamic ignition-timing procedures, carburetor disassembly, float-level adjustment, and fuel-pump pressure and volume tests.

• Lubrication and cooling: Oil-pressure testing, main and scavenge pump inspection, coolant replacement, cooling-system pressure tests, and radiator, fan, thermostat and water-pump checks.

• Clutch and transmission: Wet-clutch inspection, friction-disc replacement, shift-mechanism diagnosis, transmission disassembly and reassembly, and output-shaft torque-damper service.

• Final drive: Drive-hub and driveshaft removal, ring-and-pinion backlash checks, bearing-preload inspection, control-spacer selection, and coupling and universal-joint inspection.

• Brakes and chassis: Hydraulic brake bleeding, caliper and master-cylinder inspection, fork service, steering-bearing replacement, and wheel, axle and brake-disc inspection.

• Electrical troubleshooting: Starter-motor inspection, ignition and charging-system tests, switch and instrument checks, and separate wiring diagrams for early and late models.

This manual suits mechanically qualified owners and technicians with the required tools; Honda recommends dealer-only service for the safety-marked maintenance items.

Engine Teardown and Valve Timing

Repair depth: Cylinder-head maintenance can be performed with the engine in the frame. Lower-end and internal transmission repairs require engine removal and crankcase separation. Bearing-selection charts match crankshaft, crankcase and connecting-rod codes to color-coded replacement inserts, with Plastigauge checks to verify clearance.

Crankshaft assembly and cylinder-head component views support identification during repair. Engine-mount torque-sequence charts, cylinder-head tightening illustrations and valve-timing-mark views provide reassembly references.

Timing-belt handling: The manual warns that turning a camshaft with the belts removed and the pistons at top dead center can cause valve-to-piston contact and engine damage.

When working on heavy components or pressurized systems, always verify you are using the correct lifting equipment and protective gear to prevent personal injury or damage to the motorcycle.

Carburetor Versions and Tune-Up References

The fuel chapter distinguishes pre-emission and emission-controlled configurations. Its idle-drop mixture procedure applies to motorcycles manufactured after December 31, 1977; earlier versions have their own pilot-screw settings.

Vacuum-gauge hookup and stroboscopic timing views show the test arrangements. Primary and secondary fuel-circuit drawings explain delivery at different throttle openings, alongside the air-cutoff valve’s function during deceleration.

Cooling-System Diagnosis and Pump Replacement

The cooling chapter relates overheating and coolant loss to circulation, fan operation, radiator-cap performance and possible cylinder-head gasket leakage. Pressure-test observations help distinguish external leaks from internal leakage.

Water-pump coverage includes removal, inspection and assembly replacement. The manual specifically directs replacement of a worn or damaged pump rather than internal pump repair.

Clutch and Final-Drive Service Limits

Clutch outer-drum and scavenge-pump work require engine removal, while friction-disc service is described with the engine in the frame. An engine-flushing procedure addresses debris from disintegrated clutch friction discs.

The final-drive chapter explains preload and gear-engagement checks. Damage to the ring gear, pinion gear or rear pinion bearing calls for replacement of the drive-hub assembly.

Year-Specific Steering, Brakes and Wheels

Separate sections distinguish 1975–1977 and 1978–1979 steering bearings, brake specifications and wheel assemblies. The front master-cylinder inspection also identifies the different 1979 dimensions.

ComStar wheel runout is not adjustable, and its rear tire is not interchangeable with the earlier wire-spoked-wheel tire. These distinctions help identify the applicable inspection data and replacement components.

Electrical Tests and Generator Access

System-specific troubleshooting lists and illustrated test setups connect symptoms with the relevant checks before components are selected for replacement. Tests cover starter-relay continuity, ignition-coil output, ballast resistance, rectifier operation, regulator performance and instrument sensors.

Reserve-lighting tests apply to the earlier models; the manual identifies that system as absent on 1978–1979 machines. Junction-box connector views support the later wiring diagram.

Charging-system components can be tested on the motorcycle, but AC-generator service requires engine removal.

Selected Carburetor Bore and Float-Level Data

The year-by-year carburetor table lists 32 mm venturi bores for 1975–1977 and 31 mm for 1978–1979, including emission-controlled versions. The same table separates jetting and pilot-screw settings by configuration.

Float level is listed at 21 mm (0.827 in) across the specified carburetor models, with a separate illustration showing the measurement reference.