1977 Cessna 172N / Reims F172N Skyhawk Aircraft Factory Service Manual (P/N D2012-13-RAND-1300-7/76)

This factory service manual provides detailed maintenance procedures for the 1977 Cessna 172 Skyhawk Series, including the 172N, Reims/Cessna F172N and Skyhawk II. The original issue is dated July 1, 1976; the cover carries reference D2012-13-RAND-1300-7/76.

Text search and wiring-sheet navigation: Existing OCR makes much of the text searchable, but some tables and diagram labels are missed. The 64 embedded bookmarks open major sections and individual wiring sheets. Small wiring labels require zooming; portions of the blind-encoder wire table remain faint.

• Engine and ignition: Engine removal and installation, carburetor adjustment, internal magneto timing, and magneto-to-engine timing procedures.

• Fuel system: Tank removal and installation, selector-valve disassembly and reassembly, strainer servicing, and fuel-vent and bleed-passage checks.

• Flight controls: Aileron, elevator and rudder rigging, elevator trim-tab actuator repair, and electric wing-flap motor, switch and linkage checks.

• Landing gear and brakes: Nose gear strut and shimmy dampener servicing, torque-link inspection, master-cylinder repair, and hydraulic brake system bleeding.

• Instrument systems: Pitot-static leak testing, fuel-quantity transmitter calibration, vacuum-system troubleshooting, and instrument removal and replacement.

• Electrical systems: Battery and alternator troubleshooting, external-power checks, lighting circuits, and component wiring diagrams with wire and equipment tables.

• Structural repair: Airframe damage evaluation, skin and spar repairs, control-surface balancing, and repair guidance for plastic and fiberglass components.

Cessna wrote this manual for experienced mechanics, with step-by-step maintenance procedures to assist less-experienced mechanics.

Lycoming Engine, Ignition and Propeller Service

The engine section covers the Lycoming O-320-H2AD installation with a Marvel-Schebler MA-4SPA carburetor and Bendix D4RN-2021 dual magneto. Ignition procedures identify Bendix rotor holding tool 11-8465 and timing light 11-9110.

Engine oil and filter servicing, induction checks, exhaust leak testing, and engine-control adjustment accompany the removal and installation procedures. The starter cautions explain how rotating its terminal bolt can break the internal conductor to the field coils.

Full engine and accessory overhaul is referred to separate manufacturer publications. The fixed-pitch McCauley propeller section covers removal and installation, with repair referred to the propeller manufacturer's instructions.

Fuel Tanks, Selector Valve and Priming Options

The fuel section distinguishes standard and long-range tanks, along with the standard single-cylinder and optional three-cylinder primer arrangements. Selector-valve inspection criteria and a spring-compressor illustration support valve servicing; vent and bleed-passage troubleshooting addresses restricted fuel flow and tank distortion.

Control Rigging and Landing-Gear Diagnosis

Control travel checks reference the SE716 inclinometer, and a fabrication drawing details the Control Column Neutral Rigging Tool. The Flap System Schematic traces the motor-driven cables, pulleys and push-pull rods; separate procedures cover the follow-up linkage and limit switches.

Nosewheel-shimmy troubleshooting separates wheel imbalance, bearing or linkage looseness, and dampener faults. That distinction helps narrow a shimmy complaint before choosing a repair procedure; brake coverage extends to master-cylinder Lock-O-Seal replacement and wheel-brake inspection.

Airframe Inspection, Storage and Structural Repair

Content spans ground handling, lubrication, and 100-hour and annual inspections. Procedures for temporary and indefinite storage are detailed alongside return-to-service checks. Reference Stations diagrams, Jacking and Leveling views, and Lubrication charts identify airframe reference points, lifting locations and service points.

Fuselage, wing and empennage coverage includes repair-versus-replacement criteria and control-surface balancing. The wing attachment cautions explain how misaligned eccentric bushings can damage the spar bolt hole; painting guidance addresses finishes and plastic-component compatibility.

Section 1 lists airframe dimensions, control surface travel limits, and fluid capacities. The Recommended Nut Torques tables list torque values for steel nuts on oil-free cadmium-plated threads in both fine and coarse series. Component sections supply clearances and wear limits.

Instruments, Electrical Circuits and Cabin Systems

Vacuum-system diagnosis covers the pump and relief valve; instrument procedures focus on system testing and removal or replacement, with internal instrument repair assigned to specialist facilities. Cabin heat, defrost and ventilation troubleshooting follows the utility-system controls and ducting.

The Electrical Load Analysis Chart accompanies charging-system diagnosis and wiring coverage for lighting, instruments and electric flaps. Nav-O-Matic autopilots and internal servicing of communications and navigation equipment require separate publications.

For aircraft maintenance, cross-reference these archival specifications with current FAA directives and manufacturer service information, and use calibrated equipment prior to evaluating or servicing aircraft components.

Printable PDF and Included Pages

Supplied as one printable, English-language, 298-page PDF. This total includes six front-matter pages (one blank), the inserted 20-16A/20-16B pair (one blank), and seven other blank pages.