Operating and Maintaining the Lull 644 and 844 Telehandlers: A Practical Guide for Owners and Technicians

[MikePhua]

Introduction: Telehandlers That Shaped a Generation
The Lull 644 and 844 telehandlers, produced in the late 1980s and early 1990s, remain iconic in the world of material handling. Known for their rugged build and reliable performance, these machines were widely used in construction, agriculture, and industrial settings. Despite their age, many units are still in operation today, thanks to their mechanical simplicity and the dedication of owners who maintain them. This guide explores key operational insights, maintenance strategies, and field anecdotes that bring these machines to life.
Terminology Clarification

• Telehandler: A telescopic handler used to lift and move materials, often equipped with forks or buckets.
  
• Operator Console: The dashboard area containing gauges, switches, and controls.
  
• Hydraulic Cylinder: A mechanical actuator that uses pressurized fluid to produce linear motion.
  
• Hub Assembly: The component housing the wheel bearings and axle connection.
  
• Delphi Injection Pump: A fuel delivery system used in diesel engines, known for precision metering.
  

Machine Identification and Engine Variants
The Lull 644 and 844 models were produced with various engine configurations depending on the year and serial number. Common engines include:

• Deutz F4L912: An air-cooled 4-cylinder diesel engine with a reputation for durability.
  
• Perkins 4-cylinder diesel: Known for smooth operation and widespread parts availability.
  
• John Deere diesel: Found in later models, often identified by serial numbers beginning with “JD.”
  

Engine identification can be aided by locating the serial number plate in the cab and inspecting the injection pump type. Delphi pumps are typically associated with Perkins engines.
Field Anecdote: The Mystery Engine
One operator in Ohio discovered a 4-cylinder diesel engine in his Lull 644 TT 34 but was unsure of its origin. After consulting with other owners and examining the Delphi injection pump, it was confirmed to be a Perkins engine. This highlights the importance of community knowledge and visual inspection in identifying legacy components.
Hydraulic Cylinder Repairs: A DIY Perspective
Hydraulic cylinders on older Lull telehandlers are prone to leakage due to seal degradation. While some owners opt for professional rebuilds, others tackle the job themselves. Key steps include:

• Removing the cylinder from the frame using a hoist or jack.
  
• Disassembling the cylinder with a spanner wrench or pipe wrench.
  
• Replacing seals and wipers with OEM or aftermarket kits.
  
• Reassembling and pressure testing before reinstallation.
  

In New York, one technician noted that local shops charged exorbitant fees for cylinder rebuilds, prompting him to document the process with photographs for future reference.
Hub Assembly Rebuild: A Slow but Necessary Task
Rebuilding the rear hub assembly is a common maintenance task, especially on machines that have sat idle. The process involves:

• Removing the wheel and brake components.
  
• Extracting the hub and inspecting bearings.
  
• Cleaning and repacking bearings with grease.
  
• Replacing seals and reinstalling the assembly.
  

One owner in Louisiana reported slow progress on his 644 due to competing projects and summer heat, underscoring the patience required for restoration.
Best Practices for Telehandler Maintenance

• Inspect Hydraulic Cylinders Annually
  Look for leaks, pitting, and rod wear.
  
• Change Engine Oil Every 250 Hours
  Use manufacturer-recommended viscosity and filters.
  
• Grease Pivot Points Monthly
  Prevents wear and ensures smooth articulation.
  
• Check Tire Pressure Weekly
  Uneven pressure can affect stability and steering.
  
• Flush Hydraulic Fluid Every 1,000 Hours
  Removes contaminants and maintains system performance.
  

Historical Insight: The Rise of the Lull Brand
Lull telehandlers gained popularity in the 1980s for their unique horizontal boom design, which allowed for precise load placement. The 644 and 844 models were among the most widely adopted, especially in masonry and framing applications. Their legacy continues through JLG, which acquired the brand and integrated its innovations into newer models.
Anecdote: Salvage and Restoration in the Midwest
A technician in Montana acquired a 1990 Lull 844 and began sourcing parts for restoration. He found a salvage yard specializing in Lull components and began replacing the seat, toolbox door, and hydraulic lines. The project became a labor of love, with each part telling a story of the machine’s past.
Final Thoughts: Keeping the Legacy Alive
The Lull 644 and 844 telehandlers may be decades old, but their utility and reliability endure. With access to manuals, community support, and a willingness to learn, owners can keep these machines running for years to come. Whether lifting trusses or trenching pipe, these telehandlers remain a testament to mechanical resilience and operator ingenuity.