Fiat-Allis FR220.2 Final Drive Planetary Carrier Failure and Rebuild

[MikePhua]

The Fiat-Allis FR220.2 and Its Industrial Legacy
The Fiat-Allis FR220.2 wheel loader was part of a robust lineage of earthmoving machines produced during the 1980s and early 1990s. Fiat-Allis, a joint venture between Italy’s Fiat and the American Allis-Chalmers, was known for blending European design finesse with American mechanical durability. The FR220.2 was a mid-to-large class loader, typically weighing over 20 tons and powered by a turbocharged diesel engine delivering upwards of 220 horsepower.
These loaders were widely deployed in mining, quarrying, and large-scale construction, especially in North and South America. Though Fiat-Allis eventually merged into Fiat-Hitachi and later CNH Industrial, the FR220.2 remains a respected machine among operators and rebuilders for its straightforward mechanical systems and rugged drivetrain.
Understanding the Final Drive and Planetary Carrier Assembly
The final drive in a wheel loader transmits torque from the transmission to the wheels, reducing speed while multiplying force. In the FR220.2, this system includes a planetary gear set housed within the wheel hub. The planetary carrier holds multiple pinion gears that rotate around a central sun gear, distributing torque evenly and allowing high load capacity.
Key components include:

• Planetary Carrier: Holds the pinion gears and rotates with the wheel hub.
  
• Sun Gear: Central gear driven by the axle shaft.
  
• Ring Gear: Fixed gear that meshes with the pinions.
  
• Pinion Shafts and Bearings: Support the pinion gears and allow smooth rotation.
  
• Carrier Housing: Encloses the entire assembly and supports structural loads.
  

This design is ideal for heavy-duty applications but requires precise tolerances and clean lubrication to prevent gear damage.
Failure Scenario and Damage Assessment
In one documented case, a planetary gear in the FR220.2 broke a tooth, which then became lodged between other gears, causing the carrier housing to crack. This type of failure is typically triggered by:

• Metal fatigue from prolonged high-load operation
  
• Insufficient lubrication or contaminated oil
  
• Shock loads from sudden directional changes
  
• Manufacturing defects or improper heat treatment
  

Once a gear tooth breaks, the debris can jam the gear train, leading to catastrophic failure. In this instance, the housing itself fractured, rendering the entire assembly unusable.
Terminology Clarification

• Planetary Gear Set: A gear system with one sun gear, multiple planet gears, and a ring gear, used for torque multiplication.
  
• Carrier Housing: The structural casing that holds the planetary assembly.
  
• Torque Load: The rotational force applied to a component.
  
• Fatigue Failure: Cracking or breakage due to repeated stress cycles over time.
  

Replacement Options and Manufacturer Background
The original part number for the planetary carrier assembly was identified as 76036102A. While Fiat-Allis no longer manufactures parts, many components were sourced from third-party suppliers such as Dana Graziano, an Italian company known for producing axles and drivetrains for industrial equipment. Dana Graziano has supplied parts for brands like CNH, Liebherr, and Terex, and their axles are often tagged with serial plates that can help identify compatible replacements.
Operators seeking replacements have several options:

• Salvage yards specializing in legacy equipment
  
• European suppliers with access to Dana Graziano parts
  
• Custom fabrication shops capable of machining new carriers
  
• Rebuilt assemblies from remanufacturers
  

Inspection and Identification Tips
To confirm axle origin and part compatibility:

• Look for a metal tag or stamped serial number on the axle housing
  
• Cross-reference part numbers with Dana or CNH catalogs
  
• Measure gear dimensions and spline counts for matching
  
• Inspect bearing surfaces and shaft tolerances before reassembly
  

One technician in Alberta noted that many FR220.2 units used Dana axles, and locating the tag on the main housing was key to sourcing the correct replacement.
Repair Strategy and Preventive Measures
Once a planetary carrier fails, the repair process involves:

• Full disassembly of the final drive
  
• Removal of all gear debris and inspection for secondary damage
  
• Replacement of the carrier, pinions, bearings, and seals
  
• Cleaning and flushing of the housing to remove metal fragments
  
• Reassembly with proper torque specs and fresh gear oil
  

To prevent future failures:

• Change final drive oil every 500 hours or annually
  
• Use high-viscosity gear oil rated for extreme pressure (EP)
  
• Avoid sudden directional changes under load
  
• Monitor for unusual noise or vibration during operation
  

Field Anecdote and Lessons Learned
A contractor in Michigan shared his experience rebuilding a FR220.2 final drive after a similar failure. He sourced a replacement carrier from a decommissioned unit in Ohio and rebuilt the assembly over a weekend. The loader returned to service with improved performance, and he began inspecting planetary gears every 1,000 hours as a preventive measure.
Interestingly, he had previously worked on a Terex loader with a similar Dana axle, and the parts were nearly identical—highlighting the interchangeability of components across brands.
Conclusion
The final drive planetary carrier in a Fiat-Allis FR220.2 is a critical component that demands careful maintenance and precise repair. While failures can be severe, sourcing replacements is possible through salvage networks and European suppliers. With proper lubrication, inspection, and torque management, these legacy machines can continue operating reliably in demanding environments. The FR220.2, like many Fiat-Allis machines, proves that solid engineering and thoughtful rebuilds can extend the life of even decades-old iron.