Gehl 553 Boom Extension Chain Failure and Field Repair Strategy

[MikePhua]

The 553 and Gehl’s Compact Telehandler Lineage
The Gehl 553 is a compact telehandler designed for light construction, agricultural handling, and utility work. Introduced in the early 2000s, it featured a rated lift capacity of approximately 5,500 lbs and a maximum lift height of around 18 feet. Its compact frame and mechanical simplicity made it popular among small contractors and rental fleets.
Gehl, founded in 1859 in Wisconsin, has long specialized in compact equipment. The 553 was part of their push into the telehandler market, offering a balance between reach, maneuverability, and serviceability. Though no longer in production, the 553 remains in active use across North America, often maintained by independent operators and small shops.
Boom Extension System and Chain Configuration
The boom extension mechanism in the Gehl 553 relies on a chain-driven system rather than hydraulic cylinders alone. This design uses:

• Two extension chains
  
• One retraction chain
  
• Chain anchor points at the boom base and tip
  
• Guide rollers and tensioners
  
• Internal boom channels for chain routing
  

The chains are responsible for synchronizing the movement of nested boom sections. When the operator activates the extension function, hydraulic pressure moves the primary boom section, and the chains pull the secondary section forward. Retraction works in reverse, with the retraction chain pulling the inner boom back.
In one fleet in Alberta, a 553 was used for tree trimming. A falling limb struck the boom, snapping one of the extension chains and leaving the boom partially extended and immobile.
Symptoms of Chain Failure and Diagnostic Clues
When a boom extension chain fails, operators may observe:

• Boom extends partially but stops abruptly
  
• Hydraulic pressure builds but no movement occurs
  
• Audible clunk or snap during operation
  
• Chain ends visible inside boom channel
  
• Uneven boom alignment or binding
  

In one case from Texas, a technician noticed that the boom would retract but not extend. Upon inspection, both ends of a broken chain were visible—one near the boom tip and the other inside the rear channel. The chain had snapped cleanly, likely from impact stress.
Repair Strategy Without Boom Removal
While full boom disassembly is possible, many operators prefer field repairs that avoid removing the boom. A successful method includes:

• Fishing the new chain through the boom using a guide rod
  
• Taping the chain to a flexible rod (e.g., ground rod or conduit)
  
• Feeding the rod through the boom channel from rear to front
  
• Using gorilla tape or zip ties to secure the chain during pull-through
  
• Aligning chain ends with anchor points and securing with bolts or pins
  

Recommended tools:

• Ground rod or flexible conduit (6–8 feet)
  
• Gorilla tape or heavy-duty zip ties
  
• Flashlight and inspection mirror
  
• Torque wrench for anchor bolts
  
• Chain tension gauge (optional)
  

In one rebuild in Maine, a technician used a fiberglass fish tape and a magnet to guide the chain through the boom. The repair took under two hours and restored full extension function without removing the boom.
Preventive Measures and Chain Longevity
To prevent future chain failures:

• Inspect chain tension monthly
  
• Lubricate chains with dry film lubricant to avoid debris buildup
  
• Avoid shock loads or sudden stops during boom operation
  
• Replace chains every 2,000 hours or sooner if wear is visible
  
• Install boom guards or deflectors in forestry or demolition work
  

Recommended upgrades:

• Use high-strength alloy chains with corrosion-resistant coating
  
• Add chain inspection ports to boom housing
  
• Install limit switches to prevent overextension
  
• Use chain tensioners with visual indicators
  

In one municipal fleet in France, adding chain inspection ports reduced downtime and improved maintenance scheduling. The machines were used for streetlight maintenance and required frequent boom cycling.
Conclusion
Boom extension chain failure in the Gehl 553 telehandler can be resolved without full boom removal using creative field techniques and careful alignment. With proper inspection, tensioning, and protection, operators can extend the life of the chain system and maintain reliable boom performance. Whether lifting pallets or trimming trees, the 553 remains a capable machine—when its extension system is kept in top shape.