Restoring a 1996 JLG 45HA Articulated Boom Lift

[MikePhua]

The JLG 45HA and Its Industrial Footprint
The JLG 45HA, introduced in the mid-1990s, was part of JLG Industries’ push into hybrid-fuel articulated boom lifts designed for rugged terrain and extended reach. With a working height of approximately 51 feet and a horizontal outreach of 25 feet, the 45HA was built to serve construction, maintenance, and industrial applications. It featured a dual-fuel Ford engine capable of running on gasoline or propane, a 4x4 drivetrain, and a robust hydraulic system. JLG, founded in 1969, became a global leader in aerial work platforms, and the 45HA was one of its most versatile mid-sized models during its production run.
Engine and Hydraulic Fluid Selection
For machines operating in temperate climates like Oregon’s Willamette Valley, engine oil viscosity should balance cold-start protection with high-temperature stability. A 10W-30 or 10W-40 multi-grade oil is suitable for the Ford engine, offering reliable lubrication across seasonal temperature swings.
Hydraulic fluid selection is equally critical. AW32 or AW46 hydraulic oil, such as Citgo’s Costco-branded AW46, is appropriate for moderate climates. AW46 offers better viscosity retention in warmer conditions, while AW32 flows more easily in colder starts.
Terminology annotation:
- AW (Anti-Wear) hydraulic oil: Formulated with additives to reduce wear in pumps and valves.
- Viscosity index: A measure of how much a fluid’s thickness changes with temperature.
- Dual-fuel engine: An internal combustion engine capable of operating on two fuel types, typically gasoline and propane.
Tilt Sensor and Safety Systems
The tilt warning system on the 45HA includes a 5-degree tilt sensor designed to alert the operator when the machine is on a slope that could compromise stability. This sensor typically activates a warning light or audible alarm. A missing horn or disconnected tilt light compromises safety and should be addressed immediately.
There is usually only one tilt sensor mounted near the base of the chassis. Loose wiring or corrosion can disable the alert system, and repairs should include:

• Reconnecting or replacing damaged wires
  
• Testing sensor output with a multimeter
  
• Verifying alarm and light functionality
  

Planetary Hub Gear Oil Maintenance
The planetary drive hubs require periodic gear oil changes to prevent wear and overheating. Each hub has a drain plug and a fill plug. To service:

• Rotate the hub until the drain plug is at the bottom
  
• Remove the plug and drain the oil completely
  
• Rotate the hub until the fill plug is at the 3 o’clock or 9 o’clock position
  
• Fill with gear oil until it reaches the plug hole level
  

Recommended oil: SAE 80W-90 gear oil with EP (Extreme Pressure) additives.
Boom Bushing Failure and Structural Wear
A damaged brass bushing at the main boom pivot may indicate excessive load, lack of lubrication, or misuse. Flattened and deformed bushings suggest high compressive stress, possibly from improper use as a crane or from prolonged operation without grease.
Solutions:

• Replace both bushings and the pivot pin
  
• Inspect wear pads and telescoping sections for signs of abrasion
  
• Clean and re-lubricate all pivot points
  
• Avoid using the lift for unintended lifting tasks
  

Hydraulic Shudder and Boom Extension Issues
Shuddering during tower boom extension, especially when the main boom is horizontal, may result from dry or worn wear pads. While JLG does not officially recommend lubricating wear pads, light application of dry lubricant or silicone spray can reduce friction and improve smoothness.
Additional causes:

• Air in hydraulic lines
  
• Contaminated fluid
  
• Valve hesitation due to electrical faults
  

Governor Adjustment and Idle Control
The Ford VSG-411 engine uses an E-301 electronic governor with an SF actuator to regulate RPM. The governor modulates throttle based on load demand, with three distinct stages:

• Base idle (around 800 RPM)
  
• Mid-range during boom operation (1,500 RPM)
  
• High throttle during drive mode (up to 3,000 RPM)
  

To adjust:

• Back off the carburetor idle screw to allow the actuator to control idle
  
• Set base idle using the governor controller
  
• Inspect for surging above 3,000 RPM, which may indicate faulty wiring or actuator feedback
  

Terminology annotation:
- Governor actuator: A motorized arm that adjusts throttle position based on electronic signals.
- Surging: Rapid fluctuation in engine RPM due to unstable control signals or fuel mixture.
Electrical Faults and Boom Harness Damage
Loss of tower down function from the platform often stems from broken wires in the boom harness. Years of telescoping movement cause cyclic bending, which can fracture conductors inside the powertrak.
Troubleshooting steps:

• Test continuity from platform switch to ground control terminal
  
• Inspect for pinched or taped wires near hydraulic cylinders
  
• Use spare wires in the harness if available
  
• Replace boom cable if multiple functions fail
  

Propane System Restoration and Fuel Lock Valve
The disconnected component near the engine is likely a fuel lock valve, which prevents gasoline flow until oil pressure builds. In dual-fuel systems, this valve ensures safe startup and prevents flooding. If the propane system is incomplete, it should be restored with:

• A certified tank and regulator
  
• Fuel lines rated for propane
  
• Proper routing and shielding from heat sources
  

Sand Contamination and Component Cleaning
Machines used in sandblasting often accumulate copper slag—a coarse abrasive used as a silica-free alternative. This material can bury valves, hoses, and electrical components, leading to corrosion and shorts.
Cleaning advice:

• Remove slag manually and flush with low-pressure water
  
• Inspect valve coils and connectors for damage
  
• Replace weathered hoses and seals
  
• Apply dielectric grease to electrical terminals
  

Conclusion
Restoring a 1996 JLG 45HA requires a blend of mechanical insight, electrical troubleshooting, and hydraulic finesse. From governor calibration to tilt sensor repair, each subsystem plays a role in safe and efficient operation. With careful attention to wear points, wiring integrity, and fluid selection, this classic boom lift can be brought back to full working order—ready to rise above its past and serve reliably once again.