Ford A66 Front Axle Challenges

[MikePhua]

Incident Overview
During a routine task of seating a tire on a Ford A66 loader, a sudden wheel failure occurred—a ring came loose, causing rapid deflation and the tire to dislodge forcefully. To everyone’s relief, no one was nearby when the event unfolded. In its wake, the wheel and connected axle slid clean out of the housing, revealing a failure of the axle “keeper”—a bolted clamp designed to secure the axle in place. The keeper had fractured, allowing the axle to drop out of its housing.
Maintenance and Repair Process
Once inspected, the internal components revealed that the keeper had marred the serrations in the planetary gear housing. Fortunately, these were cleaned and smoothed effectively. The repair involved some trial-and-error shimming to achieve proper bearing preload:

• Disassemble, insert various thickness shims, re-tighten, check axial play
  
• Repeat until minimal but appropriate endplay is achieved
  

After reassembly, the loader ran smoothly and has now driven over ten miles with tires filled with slime, maintaining air pressure consistently. The handful of users involved highlighted the loader’s unexpected value, purchased cheaply and rebuilt with simple parts and dedication.
Practical Fix Tips
A seasoned technician offered a clever way to determine ideal shim thickness:

• Insert three lead shot balls—slightly thicker than desired shims—spaced evenly inside the axle end
  
• Torque down the keeper, remove it, and measure the balls with a micrometer
  
• Average their thicknesses to identify the correct shim pack size
  

This technique can save time and ensure accurate bearing preload without endless disassembly.
Underlying Issues and Insights
Several users suggested that keeper failure doesn’t occur in isolation. It often indicates deeper problems like bearing fatigue or internal misalignment. Consequently, experts recommend removing the entire axle and “trumpet” housing for a thorough inspection—not just a quick fix. This helps assess damage to final drive components beyond just the keeper.
Some speculated that the initial tire incident merely exposed a weakness that was already building, emphasizing the importance of preemptive maintenance on aging parts.
Safety and Repair Advice

• Always use proper supports—never rely on unstable blocks or jacks that could collapse under load.
  
• Use sturdy timber cribbing or certified stands when dismantling heavy axle assemblies.
  
• Conduct a comprehensive teardown of the axle system to inspect internal gears, bearings, seals, and the retention keeper.
  

Conclusion
The Ford A66 loader’s front axle ordeal is a reminder of the hidden wear and expectations surrounding aging machinery. A seemingly minor component failure—like a broken keeper—can cause dramatic results. Yet, with a modest investment of time, careful diagnosis, and smart shimming, such failures can be rectified. The loader’s story—rescued, rebuilt, and still serving—reflects the dedication of its owner and the enduring maintainability of older machinery.
With preparation and know-how, even unexpected mechanical failures can be managed, restoring functional value and reliability to well-used equipment.