JLG 120HX Boom Lift Service Manual
114 pages · Publication 3120686
Added to your cart. View cart
- Models
- 120HX
- Manual type
- Service Manual
- Pages
- 114
- Publication
- 3120686
- Condition
- Brand new

What's inside
From the manual's own table of contents: 159 sections, 204 entries. See sample pages (PDF, 495 KB)
Maintenance1 topic
- Capacities
Engine Crankcase1 topic
- Component Data
Hydraulic Filter - Inline1 topic
- Performance Data
Show all 159 sections
Wheelbase1 topic
- Function Speeds (Machines Built Prior to S/N 38697)
Ground to 120’ to Ground3 topics
- Function Speeds (Machines Built After S/N 38697)
- Torque Requirements
- Lubrication
Lubrication Specifications1 topic
- Pressure Settings - PSI (Bar)
Frame Mounted Control Valve3 topics
- Serial Number Locations
- Major Component Weights
- Boom Tape
w/Boom Wipers4 topics
- Cylinder Specifications
- Critical Stability Weights
- General
- Servicing and Maintenance Guidelines
Lubrication and Servicing1 topic
- Lubrication Information
Changing Hydraulic Oil2 topics
- Cylinders - Theory of Operation
- Valves - Theory of Operation
Crossover Relief Valves1 topic
- Boom Chains
Inspection Procedure2 topics
- Wear Pads
- Drift Test
Lift Cylinder1 topic
- Cylinder Checking Procedures
Frame Jack Cylinders1 topic
- Cylinder Removal and Installation
Master Level Cylinder Installation1 topic
- Cylinder Repair
Assembly1 topic
- Boom Maintenance
Installation1 topic
- Tilt Alarm Switch
Voltmeter Adjustment1 topic
- Limit Switch Adjustments
Horizontal Cut-Out Switch2 topics
- Throttle Checks and Adjustments - Deutz Engine
- Pressure Setting Procedures
Frame Valve1 topic
- Swing Bearing
Swing Bearing Torque Values5 topics
- Drive Torque Hub
- Swing Torque Hub
- swing brake
- Drive Brake
- Free Wheeling Option
To Engage Drive Motors and Brakes (Normal Operation)1 topic
- PQ Controllers
RAMP Adjustment2 topics
- Boom Marking Tape Installation
- Boom Length/Angle Sensor Adjusting Procedure
Lift Down Speed Limit Adjustment1 topic
- Load Management System
Load Management System Daily Check6 topics
- Load Management System Adjustment
- Turntable Springs
- Drive Motor Adjustment Procedure
- Preventive Maintenance and Inspection Schedule
- Troubleshooting
- Hydraulic Circuit Checks
Inside this manual
Real pages from this service manual (114 pages). Open the sample pages (PDF, 494 KB)
- Specifications, page 20: SECTION 1 - SPECIFICATIONS
- Troubleshooting, page 83: SECTION 3. TROUBLESHOOTING
- Diagram, page 110: Figure 3-6. Hydraulic Schematic - (Sheet 1 of 2)
Other manuals for this machine
Save 10% on 2 manuals, 15% on 3 or more. Other manuals for the 120HX are listed below. Editions cover different serial number ranges: check the serial coverage and tick only the ones that match your machine.
Added to your cart. View cart
This is a service manual
Here's how it compares to the other manual types.
Service manual
Factory repair procedures and technical information such as specifications, troubleshooting, and wiring and hydraulic diagrams, for the models and systems the manual covers. See What's inside for its topics.
Operator's manual
Safe operation, controls, maintenance schedules, lubrication points, inspections, and basic checks. Repair procedures are in the service manual.
Parts manual
Illustrated diagrams with factory part numbers for identifying components and ordering parts. Repair procedures are in the service manual.
Engine service manuals are sometimes sold separately, since certain machine models were offered with more than one engine option.
What it's used for
Factory manual for in-house farm and construction shop use. Straightforward, complete, and easy to follow. It contains the OEM information dealership service departments and parts counters use to diagnose problems, identify components, and perform maintenance or repairs correctly.
Service shops and owner/operators who repair their own equipment
Identifying correct parts and seeing how assemblies come apart and go back together
Keeping equipment running with less downtime
Factory manual, 114 pages
Quantity one is the manual described above.
Fast free USA shipping
Ships in 1 business day.
60-day returns
Free if the mistake is ours. A manual ordered in error must come back unopened in its shrink-wrap; you pay return shipping and a 20% restocking fee applies. Return policy
Other editions and similar models
Questions about model, serial number, engine coverage or contents? Contact us before purchasing and we'll help confirm it's the right manual. Please verify the manual type, machine model, serial number range and engine coverage before purchasing: manuals ordered in error carry a 20% restocking fee (return policy).