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Part of the John Deere Repair Manuals.
This is the full John Deere factory technical repair manual for the 770A, 770AH, 772A and 772AH motor graders, the same shop-level book a dealer tech pulls off the shelf. It opens with general information and lubrication, then works through the running gear front to back: wheels, axles and the suspension system, the power shift transmission and torque converter, the 6531 cu. in. diesel engine, transfer drive and steering. Brakes get their own two sections, service and parking-emergency, with full teardown and adjustment. The electrical section covers batteries, charging, starting and wiring, and the frame, cab and sheet metal sections walk the structure and operator's station. The back half is where a grader manual earns its keep: the main hydraulic system, the grading device (moldboard, circle and drawbar), ground conditioning tools like the scarifier and ripper, the Automatic Blade Control (ABC) system, and a dedicated system testing section for chasing hydraulic and electrical faults with real test points instead of guesswork.
What's Inside This John Deere 770A-772A Manual
| System | Pages | Key Topics |
|---|---|---|
| General Information | 17-80 | Specifications, Predelivery, Delivery and After-Sale Services, Lubrication |
| Wheels, Axles and Suspension System | 81-202 | Wheel Bearings, Tire and Rim Service, Axle Housings, Oscillation and Suspension Repair |
| Transmission and Torque Converter | 203-282 | Power Shift Clutch Packs, Controls Linkage, Gears and Shafts, Torque Converter Service |
| 6531 Cu. in. Diesel Engine | 283-446 | Removal and Installation, Crankshaft and Main Bearings, Cylinder Head, Fuel Injection, Turbocharger |
| Engine Auxiliary Systems | 447-464 | Cooling System, Air Intake and Exhaust, Engine Mounting, Fuel Tank and Lines |
| Transfer Drive and Steering System | 465-516 | Transfer Case, Tandem Drive Chains, Power Steering Pump and Valve, Steering Cylinders |
| Service Brakes and Parking-Emergency Brakes | 517-552 | Brake Disc and Caliper Service, Hydraulic Brake Circuit, Parking Brake Linkage and Adjustment |
| Equipment Attaching | 553-556 | Drawbar Mounting, Blade Attaching Points, Front-Mounted Attachment Linkage |
| Electrical Systems | 557-634 | Batteries, Starting Circuit, Alternator and Regulator, Lighting, Wiring Harness and Schematics |
| Frame, Chassis and Supporting Structure | 635-648 | Main Frame Inspection, Articulation Hitch, Bottom Guards, Bumpers |
| Operator's Station | 649-706 | Cab Enclosure, Seat and Seat Belt, Heating and Air Conditioning, Controls and Instrument Panel |
| Sheet Metal, Safety and Convenience | 707-726 | Hoods and Panels, Guards and Shields, Safety Decals, Convenience Accessories |
| Main Hydraulic System | 727-812 | Hydraulic Pump and Manifold, Circle Drive Circuit, Blade Lift and Tilt Circuits, Filters and Reservoir |
| Grading Device | 813-908 | Moldboard, Circle Turn Mechanism, Drawbar, Blade Side Shift and Tip |
| Ground Conditioning Tools | 909-942 | Scarifier, Ripper, Front-Mounted Tool Linkage and Hydraulics |
| Automatic Blade Control (Abc) and System Testing | 943-1330 | Abc Sensors and Solenoid Valves, Grade Control Setup, Hydraulic and Electrical System Test Points |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| 770A, 770AH, 772A, 772AH | ||
| Engine Gross Power (SAE) | 160 hp (119 kW) | p. 17 |
| Engine Net Power (SAE) | 150 hp (112 kW) | p. 17 |
| Engine Bore and Stroke | 4.56 x 4.75 in. (116 x 121 mm) | p. 17 |
| Engine Piston Displacement | 466 cu. in. (7.638 L) | p. 17 |
| Engine Compression Ratio | 14.9 to 1 | p. 17 |
| Engine Maximum Torque | 465 lb-ft (630 Nm) @ 1,300 rpm | p. 17 |
| Fuel Tank Capacity | 70 gal. (265.0 L) | p. 18 |
| Cooling System Capacity | 10 gal. (38 L) | p. 18 |
| Front Wheel Retaining Cap Screw Torque | 130 lb-ft (177 Nm) | p. 38 |
| JD770-A / JD772-A rear wheels | ||
| Rear Wheel Retaining Cap Screw Torque | 300 lb-ft (407 Nm) | p. 39 |
John Deere 770A-772A Common Problems This Manual Covers
Circle drive or blade lift circuit loses pressure and the blade creeps or drifts under load.
Start with fluid level and filter condition, then move to the pump output and relief valve settings covered in the Main Hydraulic System section. A creeping blade under load usually traces to a worn circle drive motor, a leaking lift cylinder seal, or a control valve spool that is not sealing, and the section's test points let you isolate which one before tearing into the circle or the cylinders.
Manual Section: Main Hydraulic SystemPower shift transmission is slow to shift or slips under load.
Slow or slipping shifts point to worn power shift clutch packs, a control linkage out of adjustment, or low torque converter charge pressure. The Transmission and Torque Converter section gives the clutch pack inspection procedure and the converter pressure test so you can confirm whether the fault is mechanical wear in the clutches or a hydraulic control problem before a rebuild.
Manual Section: Transmission and Torque ConverterEngine shows low power or excessive smoke under load.
Low power with smoke on this turbocharged diesel points to fuel injection, turbocharger boost, or air intake restriction. The engine section covers the fuel injection system and turbocharger service, and walks the inspection steps so you can separate a fouled injector or a failing turbo from a simple clogged air filter before condemning the injection pump.
Manual Section: 6531 Cu. In. Diesel EngineSteering feels heavy, delayed, or wanders at working speed.
Heavy or delayed power steering is usually a pump output, relief valve, or steering cylinder seal issue rather than a mechanical linkage fault on these graders. The Steering System section covers the pump and valve service and the cylinder rebuild procedure, letting you confirm hydraulic pressure at the test point before replacing the pump or cylinders.
Manual Section: Steering SystemFrequently Asked Questions
The circle drive on my 770A leaks down and the blade drifts overnight, where do I start?
The Main Hydraulic System section covers the circle drive circuit end to end, from the pump and manifold through the control valve to the circle turn motor. Work the pressure and leakage test points there first to isolate whether the fault is a worn circle drive motor, a leaking control valve spool, or a bad seal at the circle itself before you pull anything apart.
My 772A Automatic Blade Control keeps hunting and won't hold grade, what's the fix?
The Automatic Blade Control section walks the sensor and solenoid valve layout and gives the setup and calibration steps for grade control. A hunting ABC circuit is almost always a sensor mounting or solenoid response issue rather than a hydraulic problem, and the manual's test points let you confirm which side of the system is at fault before you start swapping parts.
Does this manual cover the torque converter and power shift transmission separately?
Yes. The Transmission section covers the power shift clutch packs, controls linkage and gears, and includes the torque converter service and rebuild procedures in the same section, so you have both the mechanical teardown and the hydraulic clutch control in one place.
Is the wiring for the 770AH and 772AH articulated models different from the 770A?
The Electrical Systems section covers the shared battery, starting and charging circuits plus lighting and instruments common to all four models, with wiring schematics that note where the articulated AH variants differ. Check the schematic legend for your serial range before tracing a harness fault.
What's covered for the scarifier and ripper attachments?
The Ground Conditioning Tools section covers the scarifier and ripper linkage and their hydraulic circuits separately from the main blade hydraulics, including mounting and the hydraulic hookup back to the main system.
