JLG Boom Lift 340AJ Service & Maintenance Manual 3122337900 2026

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JLG Boom Lift 340AJ Service & Maintenance Manual 3122337900 2026
Size: 72.40 MB
Format: PDF
Language: English
Brand: JLG
Type of Machine: Boom Lift
Type of Manual: Service & Maintenance Manual, Electrical and Hydraulic Diagrams
Model: JLG 340AJ Boom Lift
Part Number: 3122337900
Publication Date: 2026
Number of Pages: 690 Pages

Contents:
Safety

General​

1.1.1 Disclaimer​

1.1.2 Operation & Safety Manual​

Safety Information​

1.2.1 Safety Alert System and Signal Words​

Safety Hazards​

1.3.1 Personal Hazards​

1.3.2 Equipment Hazards​

1.3.3 General Hazards​

1.3.4 Operational Hazards​

Safety Decals​

Machine Verification​

General Machine Information and Specifications

Specifications​

2.1.1 Machine Specifications​

2.1.2 Machine Dimensional Data​

2.1.3 Engine Data​

2.1.4 Tires​

2.1.5 Critical Stability Weights​

Machine Temperature Chart​

Serial Number Location​

Fluids and Lubrication​

2.4.1 General Information​

2.4.2 Hydraulic Oil​

2.4.3 Changing Hydraulic Oil​

2.4.4 Lubrication Specifications​

2.4.5 Fluids​

2.4.6 Capacities​

2.4.7 Lubrication Schedule​

Machine Characteristics​

2.5.1 Ground Control Keyswitch System​

2.5.2 Platform Control Enable System​

2.5.3 Cold Start System (Diesel)​

2.5.4 Fuel level Cutout System​

2.5.5 Drive System​

2.5.6 Drive Orientation System​

2.5.7 Function Speed Control System​

2.5.8 Oscillating Axle System​

2.5.9 Chassis Tilt Indicator System​

2.5.10 Platform Load Sensing System​

2.5.11 Jib Lift End Of Stroke Dampening​

2.5.12 Emergency Descent System​

2.5.13 Side Entry Platform​

2.5.14 Transport Position Sensing System​

2.5.15 Beyond Transport Position - Drive Speed Cutback System​

2.5.16 Drive/Steer - Boom Function Interlock System (UKCA/CE ONLY)​

2.5.17 MSSO​

2.5.18 Counterweight​

Clearsky Smart Fleet (If Equipped)​

2.6.1 General​

2.6.2 ClearSky Smart Fleet™ — Access Control​

Maintenance and Inspection Schedules

Machine Preparation, Inspection, and Maintenance​

3.1.1 General​

3.1.2 Preparation, Inspection, and Maintenance​

3.1.3 Pre-Start Inspection​

3.1.4 Pre-Delivery Inspection and Frequent Inspection​

3.1.5 Annual Machine Inspection​

3.1.6 Preventive Maintenance​

Service and Guidelines​

3.2.1 General​

3.2.2 Safety and Workmanship​

3.2.3 Cleanliness​

3.2.4 Components Removal and Installation​

3.2.5 Component Disassembly and Reassembly​

3.2.6 Pressure-Fit Parts​

3.2.7 Bearings​

3.2.8 Gaskets​

3.2.9 Bolt Usage and Torque Application​

3.2.10 Hydraulic Lines and Electrical Wiring​

3.2.11 Hydraulic System​

3.2.12 Lubrication​

3.2.13 Battery​

3.2.14 Welding on JLG Equipment​

Preventive Maintenance and Inspection Schedule​

3.3.1 Daily​

3.3.2 First 50 Hours​

3.3.3 Every 150 Hours or 3 Months​

3.3.4 First 300 Hours or 6 Months​

3.3.5 Every 500 hours or 6 months​

3.3.6 Every 600 Hours or 1 Year​

3.3.7 Every 1000 Hours or 1 Year​

3.3.8 Every 1200 Hours or 2 Years​

Pins and Composite Bearing Repair Guidelines​

Tires and Wheels​

3.5.1 Tire Inflation​

3.5.2 Tire Damage​

Fuel Tank Inspection​

Boom Inspection and Maintenance​

3.7.1 Boom Cleanliness Guidelines​

3.7.2 Boom Wear Pad Inspection​

Hydraulic Filter Replacement​

3.8.1 Hydraulic Filter Removal​

3.8.2 Hydraulic Filter Installation​

Turntable Bearing Inspection​

3.9.1 Turntable Bearing Mounting Bolt Condition Check​

3.9.2 Wear Tolerance​

3.9.3 Swing Bearing Torque Value​

Engine General Inspection​

3.10.1 General Maintenance​

3.10.2 Glow Plugs (Kubota Engine)​

3.10.3 Engine Oil Pressure Switch​

3.10.4 Engine Speed Sensor​

3.10.5 Coolant Sensor​

3.10.6 Engine Speed Actuators​

3.10.7 Engine Start​

3.10.8 Alternator Excitation​

3.10.9 Fuel Pump​

3.10.10 Shutdown​

3.10.11 GM Dual Fuel Engine​

3.10.12 Replacing Engine Oil​

3.10.13 Replacing the Oil Filter​

3.10.14 Replacing the Primary Fuel Filters​

Testing, Calibrations and Special Procedures

Special Tools​

4.1.1 Multimeter Basics​

4.1.2 Threadlocking Compound​

4.1.3 Tools Catalog​

Testing Procedures​

4.2.1 Starter​

4.2.2 SkyGuard​

4.2.3 LSS Testing and Evaluation​

Calibration Procedures​

4.3.1 JLG Analyzer​

4.3.2 Calibration Preparation​

4.3.3 Load Sensing System Calibration​

4.3.4 Calibrating Tilt Sensor​

Special Procedures​

4.4.1 Fuel Tank Cleaning and Drying​

4.4.2 Cylinder Drift​

4.4.3 Hydraulic Circuits​

4.4.4 Oscillating Axle Bleeding Procedure​

Wheel Drive Hub​

4.5.1 Roll, Leak and Brake Testing​

4.5.2 Tightening and Torquing Bolts​

4.5.3 Measuring Rolling Torque​

System Software

Load Sensing System (LSS)​

5.1.1 Theory of Operation​

5.1.2 Load Sensing Gauge Removal/ Installation​

JLG Analyzer​

5.2.1 Machine Data Access​

5.2.2 Hand Held Analyzer​

5.2.3 Analyzer Flow Chart​

Analyzer Software Accessibility​

5.3.1 Machine Set-Up​

5.3.2 Personalities​

Function Test​

5.4.1 Drive (Below Elevation):​

5.4.2 Drive (Above Elevation):​

5.4.3 Swing:​

5.4.4 Tower Lift:​

5.4.5 Main Lift:​

5.4.6 Telescope:​

5.4.7 Jib Lift:​

5.4.8 Platform Rotate:​

5.4.9 Test Notes​

ClearSky (CS550) Configuration and Troubleshooting​

5.5.1 ClearSky Smart FleetTM CS550 Configuration​

5.5.2 Troubleshooting​

Fault Codes

Fault Codes Introduction​

Engine Diagnostic​

Machine Fault Codes​

6.3.1 Fault Code Troubleshooting​

6.3.2 ClearSky Smart Fleet DTC Fault Codes​

6.3.3 LSS Troubleshooting​

6.3.4 System Fault Messages​

ClearSky CS550 Troubleshooting Procedures​

Hydraulics

General Information and Safety​

Theories of Operation​

7.2.1 Cylinders​

7.2.2 Valves​

Hydraulic Components​

7.3.1 Hydraulic Oil Tank​

7.3.2 Pressure Setting Procedure​

Torque Values​

7.4.1 Cylinder Torque Specifications​

7.4.2 Valve Torque Specifications​

Electricals

General Information​

8.1.1 Applying Silicone Dielectric Compound to Electrical Connections​

8.1.2 Dielectric Grease Application​

Electrical Connectors​

8.2.1 Deutsch Connectors​

Electrical Component Terminology​

Harness Layouts​

Board Layouts​

8.5.1 Ground Control Module Pin Connections​

8.5.2 Platform Control Module Pin Connections​

AMP Connector​

8.6.1 Applying Silicone Dielectric Compound to AMP Connectors​

8.6.2 Assembly​

8.6.3 Disassembly​

8.6.4 Wedge Lock​

8.6.5 Service - Voltage Reading​

Operator Controls and Switches​

8.7.1 Ground Control Switches​

8.7.2 Platform Control Switches​

Wiring Harness and Connector Label Diagrams​

8.8.1 Connector Labels​

8.8.2 Component Labels​

Telematics Gateway​

8.9.1 Telematics-Ready (TCU) Plug​

Electrical Installation​

Removal and Installation

Wheel and Tire​

9.1.1 Tire Replacement​

9.1.2 Wheel and Tire Replacement​

9.1.3 Removing Wheel and Tire Assembly from Machine​

9.1.4 Wheel Installation​

Chassis/Frame Assembly​

9.2.1 Axle and Drive Assemblies Troubleshooting​

9.2.2 Axle Assembly​

9.2.3 Spindle Assembly​

9.2.4 Drive Hub and Motor​

Boom​

9.3.1 Boom Components Terminology​

9.3.2 Troubleshooting​

9.3.3 Main Boom Powertrack​

9.3.4 Main Boom Assembly​

9.3.5 Jib and Rotator Assembly​

Platform​

9.4.1 Platform (Rapid Replaceable Platform)​

9.4.2 Platform Support (Traditional Design)​

9.4.3 Platform Support (Rapid Replaceable Platform)​

Engine​

9.5.1 Component Terminology​

9.5.2 Engine Serial Number​

9.5.3 Engine Replacement​

9.5.4 Coolant Overflow Tank (GM Engine)​

9.5.5 Overflow coolant tank (Kubota Engine)​

9.5.6 Pump Coupling Kit​

9.5.7 Air Filter Assembly​

9.5.8 Radiator Assembly​

9.5.9 Starter​

9.5.10 Alternator​

9.5.11 Fuel Tank​

Transmission​

Hydraulic Cylinders​

9.7.1 Main Boom Lift Cylinder​

9.7.2 Main Boom Telescope Cylinder​

9.7.3 Tower Boom Lift Cylinder​

9.7.4 Master Cylinder​

9.7.5 Platform Level Cylinder​

9.7.6 Articulating Jib and Jib Lift Cylinder​

9.7.7 Steer Cylinder​

9.7.8 Axle Lockout Cylinder​

Hydraulic Valves​

9.8.1 Valve Installation​

Hydraulic Pumps​

9.9.1 Gear Pump Assembly​

9.9.2 Axial Pump Assembly​

Electrical Components​

9.10.1 Battery​

Turntable​

9.11.1 Swing Motor​

9.11.2 Swing Drive​

Generator and Pulley​

9.12.1 For 2800W and 3500W Generator — GM Engine​

9.12.2 For 2800W and 3500W Generator — Kubota Engine​

9.12.3 For 4000W Generator - Kubota Engine​

ClearSky® LED Motion / Amber Beacon (CS550) (if equipped)​

9.13.1 ClearSky® LED Motion / Amber Beacon (CS550) (if equipped)​

Disassembly and Assembly

Drive Assembly​

10.1.1 Drive Hub​

10.1.2 Drive Motor​

Boom and Jib Assembly​

10.2.1 Main Boom Disassembly/Assembly​

10.2.2 Rotatory Actuator Disassembly/Assembly​

Platform​

Engine Components​

10.4.1 Engine Disassembly, Inspection and Service​

10.4.2 Fuel Tank​

Pumps​

10.5.1 Drive Pump​

10.5.2 Gear Pump​

Hydraulic Cylinders​

10.6.1 Disassembly and Assembly Instructions​

10.6.2 General Information​

10.6.3 Standard of Maintenance​

10.6.4 Inspection After Assembly​

10.6.5 Disassembly Procedure​

10.6.6 Assembly​

Hydraulic Valves​

Turntable​

10.8.1 Swing Motor​

10.8.2 Swing Drive​

Generator Disassembly and Assembly​

Powertrack​

10.10.1 Remove Link​

10.10.2 Install New Link​

10.10.3 Replace Fixed End Brackets​

10.10.4 Replace Moving End Brackets​

Torque/Connection Information

Hydraulic Fittings​

11.1.1 Tapered Thread Types​

11.1.2 Straight Thread Types, Tube and Hose Connections​

11.1.3 Straight Thread Types, Port Connections​

11.1.4 Flange Connection Types​

11.1.5 Tightening Methods​

11.1.6 Assembly and Torque Specifications​

11.1.7 General Tube Type Fitting Assembly Instructions​

11.1.8 Assembly Instructions for American Standard Pipe Thread Tapered Connections.​

11.1.9 Assembly Instructions for British Standard Pipe Thread Tapered Connections​

11.1.10 Assembly Instructions for 37° (JIC) Flare Fittings​

11.1.11 Assembly Instructions for 45° SAE Flare Fittings​

11.1.12 Assembly Instructions for O-Ring Face Seal (ORFS) Fittings​

11.1.13 Assembly Instructions for DIN 24° Flare Bite Type Fittings (MBTL and MBTS)​

11.1.14 Assembly Instructions for Bulkhead (BH) Fittings​

11.1.15 Assembly Instructions for O-Ring Boss (ORB) Fittings​

11.1.16 Assembly Instructions for Adjustable Port End Metric Fittings​

11.1.17 Assembly Instructions for Metric ISO 6149 (MPP) Port Assembly Stud Ends​

11.1.18 Assembly instructions for Adjustable Port End (BSPP) Fittings​

11.1.19 Assembly Instructions for Flange Connections: (FL61 and FL62)​

11.1.20 Double Wrench Method​

11.1.21 FFWR and TFFT Methods​

11.1.22 Adjustable Stud End Assembly​

11.1.23 O-ring Installation (Replacement)​

Torque Charts​

11.2.1 SAE Fastener Torque Chart​

11.2.2 Metric Fastener Torque Chart​

Schematics

Hydraulic Schematics​

Electrical Schematics​