John Deere 4110 / 4115 Technical Manual (P/N TM1984)

• Official John Deere Technical Manual TM1984 (May 2002) for 4110 CST, 4110 HST, and 4115 HST Compact Utility Tractors; a 698-page PDF identified as the North American Version.
• Separate engine repair sections cover the Yanmar 3TNE74 and 3TNE78A diesels, including compression and injection tests, timing work, cooling and lubrication diagnosis, cylinder-head service, and internal overhaul.
• Distinct gear and HST chapters document transmission removal and teardown, differential and final-drive repair, MFWD and PTO service, hydrostatic pump and motor work, pressure testing, and neutral adjustment.
• Hydraulic and steering coverage includes rockshaft and SCV diagnosis, pump-flow and relief-pressure tests, lift and sensitivity adjustments, hydraulic-pump and control-valve repair, and configuration-specific steering tests.
• Electrical material provides gear, HST, and European schematics; harness and connector views; control-module logic; circuit diagnostics; and tests for cranking, preheat, fuel shutoff, charging, PTO, lighting, and safety interlocks.
• Component-specific torque data, pressure and flow specifications, wear limits, clearances, special-tool numbers, theory of operation, diagnostic charts, and repair illustrations appear throughout.

John Deere states that this manual is written for an experienced technician. Its pressure and flow testing, diesel-injection work, electrical diagnosis, precision measurement, and heavy-component handling assume a properly equipped shop. TM1984 is a diagnostic and repair reference, not a substitute for the tractor operator’s manual.

Exact Model and Configuration Coverage

The 4110 is covered in both CST and HST form; the 4115 coverage is HST only. The 4110 uses the Yanmar 3TNE74, specified at 20 hp for CST and 21 hp for HST. The 4115 uses the 24 hp 3TNE78A. The engine chapters also reflect the 4110’s indirect-injection system and the 4115’s direct-injection system.

The publication shows machine PIN, engine, and transaxle serial-number locations but does not define a production serial range. Although identified as the North American Version, it includes a separate European electrical section for road lighting, turn signals, brake and hazard circuits, trailer wiring, and the integrated-regulator alternator, plus a Europe-specific parking-brake adjustment.

Engine and Drivetrain Systems

Each engine chapter has its own specifications, operating theory, troubleshooting, tests, adjustments, and repair procedures. Tests cover compression, valve clearance and lift, injection nozzles and pump timing, transfer-pump pressure and flow, fuel bleeding, cooling-system pressure, and engine-oil pressure. Diagnostic charts trace no-start, low-output, smoke, rough-running, overheating, low-compression, oil-pressure, and fuel-consumption complaints.

Repair coverage reaches engine and front-subframe removal, cylinder heads and valves, guides and seats, pistons and connecting rods, cylinder bores, crankshafts and bearings, camshafts and timing gears, oil pumps, cooling components, injection pumps, nozzles, and governors. The 3TNE78A section also covers starting-motor teardown and testing plus 20-amp alternator service.

The gear power-train section handles the 4110 CST transmission, differential, rear and mid PTO drives, PTO brake, MFWD output shaft, front differential, spindle housings, and final drives. HST procedures address the charge pump, hydrostatic pump and motor, swash and valve plates, valve block, PTO clutch and brake, differential carrier, rear PTO, and transaxle teardown. Warm-up, charge-pressure, PTO-pressure, lubrication-pressure, brake, and neutral-setting procedures support diagnosis before repair.

Hydraulic, Electrical, and Chassis Diagnosis

Hydraulic chapters cover the rockshaft, depth-control linkage, SCV, system relief, speed and sensitivity controls, lift cylinder, and pump. Factory procedures include pump-flow tests with and without an SCV, rockshaft lift-cycle and leakage checks, relief adjustment, and gear/HST steering tests. Wet multiple-disk brake diagnosis, pedal adjustment, brake disassembly, and configuration-specific parking-brake work are also included.

Visual references include full gear and HST electrical schematics, W1 main and W2 rear harness maps, control-module logic tables, the HST hydraulic schematic, the rockshaft hydraulic schematic, and separate gear/HST steering schematics. Electrical diagnosis pairs operating theory and schematics with fault-isolation charts for power, cranking, preheat, fuel supply, engine shutoff, charging, the control panel, lighting, PTO controls, and operator-safety switches.

Specifications, Tools, and Repair Cautions

Reference tables supply model-specific capacities, lubricant requirements, tightening torques, pressure and flow data, electrical values, adjustment specifications, and inspection limits. Named service equipment includes the JDG472 compression-test adapter, JDG692 radiator pressure-test kit, JDG991 fast-idle adjustment tool, JDG757A solenoid-valve socket, and JDG694 hydraulic-pump test fitting.

On the 3TNE74, incorrect cylinder-head-gasket orientation can block the head oil passage. In the HST, the transmission-section gasket controls bearing preload and end clearance; the manual requires a new gasket and rules out RTV or other gasket compounds.

Relieve hydraulic pressure before opening any line, support the tractor and attachments independently of a jack, and isolate the engine and electrical system before drivetrain repair. High-pressure hydraulic and diesel-injection testing requires the protective equipment and test methods specified in the manual.