Restoring a Vintage JLG 40F Boom Lift for Personal Use

[MikePhua]

The JLG 40F and Its Place in Aerial Equipment History
The JLG 40F boom lift was part of JLG Industries’ early generation of telescopic aerial work platforms, designed for construction, maintenance, and industrial access. Introduced in the late 1970s and produced through the 1980s, the 40F featured a 40-foot vertical reach and a 5-foot basket, powered by a gasoline or Wisconsin air-cooled engine. JLG Industries, founded in 1969 in Pennsylvania, quickly became a leader in access equipment, and the 40F helped establish its reputation for rugged simplicity and mechanical reliability.
Unlike modern lifts with proportional controls and electronic diagnostics, the 40F relied on direct hydraulic actuation and analog switches. Its design was straightforward, making it popular among rental fleets and small contractors. However, as ANSI and OSHA standards evolved, many units were retired or sold into private hands, where they continue to serve in barns, workshops, and rural properties.
Terminology Annotation

• Boom Lift: A type of aerial work platform with a telescoping arm used to elevate workers and tools.
  
• Proportional Valves: Hydraulic valves that allow variable flow based on joystick input, common in newer lifts.
  
• Basket: The operator platform at the end of the boom, often equipped with controls and safety rails.
  
• ANSI/OSHA Compliance: Regulatory standards for safety, inspection, and operation of aerial equipment in commercial use.
  

Identifying and Evaluating an Aging Boom Lift
One operator inherited a JLG boom lift from a neighbor and began using it for personal projects, including barn construction. The lift lacked proportional valves and showed signs of age, prompting a search for its identity and service documentation. Based on serial markings and design features, it was confirmed to be an early 40F model—likely one of the original units sold in Florida during the 1980s.
Key identifiers:

• Serial number format indicating lift height and basket size
  
• Non-factory basket with hand-bent tubing
  
• Absence of proportional hydraulic controls
  
• Wisconsin engine with manual choke and throttle
  

In one lift company in Orlando, technicians recalled building replacement baskets by hand using Greenlee conduit benders, a common practice before standardized parts became widespread. The lift in question bore the hallmarks of such field-built modifications.
Safety Considerations and Restoration Challenges
Restoring a 40F for personal use requires careful attention to safety. Unlike tractors or dozers, boom lifts operate at height, and any failure in hydraulics, structure, or controls can result in serious injury.
Common risks:

• Hydraulic hose degradation and internal rupture
  
• Electrical shorts in control wiring
  
• Cylinder seal failure leading to uncontrolled boom movement
  
• Structural fatigue in welds and pivot points
  

Recommended restoration steps:

• Replace all hydraulic hoses with rated, crimped assemblies
  
• Inspect and rebuild lift cylinders with new seals
  
• Rewire control panel using marine-grade connectors and heat shrink
  
• Reinforce basket welds and inspect for stress cracks
  
• Install safety interlocks or limit switches if absent
  

In one airport maintenance project, a retired scissor lift was rewired and restored using aviation-grade components. The team contacted the original manufacturer for safety bulletins and retrofit recommendations—a practice that should be followed with any vintage lift.
Manuals, Documentation, and Support Options
Finding a manual for a 40F can be difficult. Many dealers have purged old paper archives, and JLG may not actively support legacy models. However, several options remain:

• Contact former lift companies or rental yards for scanned manuals
  
• Reach out to JLG technical support for archived service bulletins
  
• Search enthusiast forums or restoration groups for shared documentation
  
• Use component-level manuals for engines, pumps, and valves
  

In one case, a retired lift technician had scanned his entire paper manual collection and distributed them on CD. While not commercially available, such resources circulate among restoration communities and can be invaluable.
Cost-Benefit Analysis and Practical Use
Restoring a 40F for personal use may be viable, but commercial operation is unlikely to meet current safety standards. ANSI regulations often require full teardown and certification every ten years, and retrofitting old machines to comply can exceed the cost of purchasing a newer unit.
Estimated costs:

• Hose and seal replacement: $1,200–$2,000
  
• Electrical rewiring: $800–$1,500
  
• Basket reinforcement and safety upgrades: $500–$1,000
  
• Engine overhaul (if needed): $1,000–$2,500
  

In contrast, a used modern boom lift with full compliance and proportional controls may cost $10,000–$15,000, depending on condition and hours.
Final Thoughts
The JLG 40F boom lift is a relic of early aerial access engineering—simple, sturdy, and still functional in private hands. Restoring one requires mechanical skill, safety awareness, and a realistic view of its limitations. For personal projects on private property, it can be a valuable tool. But for commercial use, the risks and regulatory hurdles make restoration impractical.
In aerial work, height magnifies every flaw. And when the boom lifts true, the basket holds firm, and the hydraulics obey, even an old machine can rise to the occasion.