JLG 60HA Tower Boom Leveling Issues and Structural Diagnostics

[MikePhua]

The 60HA’s Role in High-Reach Access
The JLG 60HA is a hybrid articulating boom lift designed for elevated work in construction, maintenance, and industrial settings. Introduced in the late 1990s, it combines a telescopic upper boom with an articulating lower tower, offering up to 60 feet of platform height and a horizontal outreach of over 40 feet. With a diesel-powered hydraulic system and 500-pound platform capacity, the 60HA became a staple in steel erection, signage, and exterior finishing.
JLG Industries, founded in 1969, pioneered the boom lift category and remains one of the top global manufacturers of mobile elevating work platforms. The 60HA was part of its push toward hybrid boom designs, blending reach and maneuverability. Sales data from 2024 shows that thousands of 60HA units remain in active service, especially in North America and the Middle East.
Understanding the Tower Boom Assembly
The tower boom on the 60HA consists of a vertical mast section that elevates the main boom pivot point. This design allows the upper boom to clear obstacles and reach over structures. The tower is raised and lowered by a hydraulic cylinder mounted within the base frame, and its alignment is critical to overall boom stability.
Terminology note:

• Tower Boom: A vertical mast that elevates the main boom pivot, increasing reach and clearance.
  
• Boom Pivot Pin: The axis around which the boom rotates, mounted atop the tower.
  
• Leveling Sensor: An electronic or mechanical device that monitors boom angle and tower alignment.
  

The tower must remain square to the chassis and level with the base frame to ensure safe operation. Misalignment can cause platform tilt, reduced outreach, and structural stress.
Symptoms of Out-of-Level Tower Boom
Operators may notice several signs when the tower boom is out of level:

• Platform tilts to one side when elevated
  
• Boom drift or sway during extension
  
• Audible creaking or popping from tower base
  
• Uneven wear on pivot pins or bushings
  
• Difficulty stowing boom into transport position
  

In one case, a contractor in Nevada reported that his 60HA’s platform leaned noticeably to the left at full extension. After inspection, the tower boom pivot pin was found to be worn unevenly, causing the boom to cant off-center. Replacing the pin and realigning the tower restored proper geometry.
Another technician in Ontario discovered that the tower cylinder mount had loosened over time, allowing the mast to shift under load. Torqueing the mount bolts and adding shims corrected the issue.
Inspection and Repair Procedures
To diagnose and correct tower boom misalignment:

• Visually inspect tower welds, pivot pins, and cylinder mounts for cracks or deformation
  
• Use a digital inclinometer to measure tower angle relative to chassis
  
• Check hydraulic cylinder for leakage or uneven extension
  
• Inspect bushings and wear pads for signs of binding or scoring
  
• Verify sensor calibration and control module readings
  

If the tower is out of square, disassemble the pivot assembly and inspect for ovalized holes or bent brackets. Replace worn components and reassemble using factory torque specs. Use alignment jigs or laser tools to ensure tower verticality.
Recommended torque specs:

• Tower pivot bolts: 450–500 ft-lbs depending on grade
  
• Cylinder mount bolts: 300 ft-lbs with thread locker
  
• Sensor bracket fasteners: 20–30 ft-lbs
  

Preventive Maintenance and Operator Tips
To prevent tower boom misalignment:

• Grease pivot pins and bushings weekly
  
• Inspect tower welds and mounts monthly
  
• Avoid side-loading the boom during outreach
  
• Use outriggers or leveling jacks on uneven terrain
  
• Monitor boom angle sensors during pre-operation checks
  

One operator in Texas added a visual bubble level to the tower base, allowing quick confirmation of alignment before elevation. Another in Dubai installed a secondary inclinometer on the platform to detect tilt drift during operation.
Design Evolution and Manufacturer Insights
Later JLG models such as the 600A and 600AJ introduced improved tower boom designs with reinforced pivot assemblies and integrated angle sensors. These upgrades reduced misalignment risk and improved platform stability.
JLG’s SkyGuard system now offers enhanced operator protection and real-time diagnostics, including boom angle monitoring and automatic shutdown in unsafe conditions. These features are retrofittable to older models like the 60HA.
Sales trends show increased demand for high-reach articulating booms in urban construction, where compact footprint and vertical clearance are essential. The tower boom remains a key feature in navigating tight spaces and complex structures.
Conclusion
An out-of-level tower boom on the JLG 60HA can compromise safety, performance, and structural integrity. With precise diagnostics, proper alignment tools, and disciplined maintenance, the issue can be resolved and prevented. The tower boom is more than a mechanical extension—it’s a critical link in the lift’s geometry, and when it’s square and true, the entire machine performs with confidence and control.