John Deere 4475, 5575, 6675, 7775 Skid Steer Loader Technical Manual (P/N TM1553)

• Coverage and document identity: John Deere 4475, 5575, 6675, and 7775 skid steer loaders, serial 010001 and higher; technical manual TM1553, April 1995, supplied as a 433-page PDF.
• Maps the four models to their diesel configurations—3015D001 (3TNE84), 3017D001 (3TNE88), 4020D001 (4TNE84), and 4022D001 (4TNE88)—with engine testing, removal, internal repair, timing, fuel-system, and cooling-system procedures.
• Separates the 4475/5575 intermediate-shaft and chain-drive system from the 6675/7775 gearbox and final-drive arrangement, then covers axle, sprocket, chain-case, gearbox, and parking-brake repair.
• Details hydrostatic pump and motor diagnosis through efficiency, case-drain, case-pressure, and high-pressure relief testing, followed by disassembly, inspection, assembly, model-specific motor repair, 6675/7775 shimming, and post-replacement startup checks.
• Covers the EATON charge pump and main control valve, boom and bucket lockout solenoids, lift and bucket cylinder repair, pressure and flow testing, drift checks, and model- and serial-specific cylinder changes.
• Provides electrical schematics and circuit diagnosis for the electronic instrument panel, cranking, charging, manual and automatic preheat, warning circuits, hydraulic lockout, lighting, switches, relays, solenoids, grounds, and wiring harnesses.
• Adds coverage for 800, 900, and 911 backhoe hydraulics, steering adjustment and repair, model-specific cab and boom tilting, boom-lock diagnosis, Quick-Attach repair, and jacking and cribbing procedures.

Serial Coverage and Engine Builds

TM1553 identifies these machines by product serial number rather than a blanket model-year range. The cover specifies serial 010001 and higher. The model-to-engine assignments matter when selecting specifications and repair procedures: the 4475 uses the 3015D001 (3TNE84), the 5575 uses the 3017D001 (3TNE88), the 6675 uses the 4020D001 (4TNE84), and the 7775 uses the 4022D001 (4TNE88).

The engine section goes beyond routine maintenance. It contains model-specific general and repair specifications, operational tests, compression and fuel-injection-nozzle testing, injection-pump timing, valve-clearance adjustment, and cooling and lubrication diagnosis. Repair chapters cover engine removal with or without tilting the cab, plus the cylinder head, valves, pistons, connecting rods, cylinder block, crankshaft, bearings, flywheel, camshaft, timing gears, oil pump, water pump, injection equipment, starter, and alternator.

Gear Drive, Hydrostatic, Hydraulic, and Electrical Systems

The gear-drive chapters keep the two chassis groups separate. The 4475/5575 arrangement uses an intermediate drive shaft and separate final-drive chains, while the 6675/7775 system adds individual gearboxes. Both receive troubleshooting, axle and chain-case service, chain and sprocket replacement, and assembly information matched to the correct configuration.

The manual distinguishes the EATON 70144 tandem pumps and 74318 motors used on 4475/5575 machines from the 70344 tandem pumps and 74624 motors used on 6675/7775 loaders. It documents pump and motor efficiency checks, case-drain and relief testing, teardown and inspection, the 6675/7775 motor-shimming procedure, and startup after pump or motor replacement.

Loader hydraulics include the EATON 25300 B2 charge pump, the EATON 34673-AAC three-spool open-center main control valve, boom and bucket lockout circuits, and lift and bucket cylinder repair. The electrical section follows individual circuits from theory of operation through diagnosis and testing, including the electronic instrument-panel module and safety-related hydraulic lockout circuit.

Serial-Break Cylinder Data, Backhoe Scope, and Service References

A key hydraulic serial break is documented for the bucket cylinders: the design changes beginning with 6675 serial 10449 and 7775 serial 10326. Old and new piston parts are not interchangeable within a cylinder, and both cylinders must remain in a matched configuration. The manual also distinguishes earlier threaded-head and later retaining-ring lift-cylinder designs used on 4475/5575 machines.

Backhoe coverage is hydraulic-system focused. The 800, 900, and 911 chapters address boom, dipperstick, stabilizer, and boom-swing circuits, along with control-valve repair, crossover-relief service, hydraulic cylinders, and the 911 dipperstick extension.

Representative visual references include the Electrical Schematic, Wiring Harness views, Hydrostatic System Schematic, Hydraulic System Schematic, Brake System Exploded View, and Backhoe Hydraulic System Schematic, with separate boom-swing layouts for 800 versus 900/911 backhoes. Factory tool references include the JDE118 Valve Guide Driver, D15001NU Magnetic Follower Holder Kit, JDF13 Nozzle Cleaning Kit, D01074AA Hydraulic Tester, and MG9862308 Cab Jack Kit.

Specifications are organized by system and include component torque tables, approved lubricants and fluid capacities, hydraulic pressure and flow test data, wear limits, clearances, electrical test values, and adjustment information. A four-page alphabetical index provides direct references to systems and procedures.

The manual flags damage-sensitive operations. Incorrect flex-plate orientation can damage the hydrostatic pump seal, while running after hydrostatic component replacement without establishing charge pressure can severely damage pumps and motors. Cab tilting, raised-boom work, and hydraulic testing require the documented boom-lock, cab-jack, cribbing, pressure-relief, and machine-support procedures.