Sourcing Undercarriage Parts for the Fiat-Allis 8B Dozer

[MikePhua]

The Fiat-Allis 8B and Its Historical Legacy
The Fiat-Allis 8B crawler dozer was a product of a transatlantic collaboration between Fiat of Italy and Allis-Chalmers of the United States. This partnership, formalized in the early 1970s, aimed to combine European engineering finesse with American industrial muscle. The 8B was introduced as a mid-size dozer with an operating weight around 18,000 to 20,000 pounds, powered by a robust 6-cylinder diesel engine and equipped with a torque converter transmission and planetary final drives.
Fiat-Allis machines were widely adopted in North and South America, especially in road building, land clearing, and agricultural development. By the mid-1980s, the company had sold tens of thousands of units globally. However, after Fiat-Allis dissolved in the early 1990s, parts support became fragmented, leaving many owners reliant on aftermarket suppliers and salvage yards.
Terminology Annotation

• Undercarriage: The assembly of track chains, rollers, idlers, sprockets, and pads that supports and propels a crawler machine.
  
• Track Chain Pitch: The distance between pin centers in a track link, critical for matching replacement parts.
  
• Carrier Roller: A roller mounted above the track frame to support the upper run of the track chain.
  
• Segmented Sprocket: A sprocket design composed of multiple bolt-on segments for easier replacement.
  

Challenges in Finding Replacement Parts
Owners of the Fiat-Allis 8B often face difficulty sourcing undercarriage components due to the machine’s age and the discontinuation of OEM support. Common parts needed include:

• Track chains and pads
  
• Bottom rollers and carrier rollers
  
• Idlers and recoil springs
  
• Sprockets and final drive seals
  

The original undercarriage was built to metric specifications, which complicates interchangeability with more common Caterpillar or Komatsu parts. Additionally, some 8B models used proprietary track pitch dimensions, making aftermarket matching a challenge.
Strategies for Identifying Compatible Parts
To locate suitable replacements:

• Measure Track Pitch and Link Height: Use calipers and tape to record dimensions and compare with known part catalogs.
  
• Check Serial Number Plate: Identify the exact model variant and production year, which affects undercarriage configuration.
  
• Consult Cross-Reference Charts: Some aftermarket suppliers maintain compatibility tables between Fiat-Allis and other brands.
  
• Use Salvage Yards: Contact heavy equipment recyclers who specialize in legacy machines.
  

In one successful case, a contractor in Missouri matched his 8B’s track chain to a D5-size aftermarket assembly by verifying pitch and bushing diameter. Though not identical, the modified setup performed reliably for over 1,000 hours.
Aftermarket Suppliers and Custom Fabrication
Several U.S.-based suppliers offer undercarriage parts for legacy machines:

• Berco (Italy-origin, U.S. distribution)
  
• General Gear & Machine
  
• Pivot Equipment Parts
  
• ConEquip Parts
  
• Linder Industrial Machinery (regional support)
  

Some suppliers offer custom fabrication for obsolete components. This includes:

• Machining new rollers from billet steel
  
• Rebuilding idlers with new bushings and seals
  
• Casting sprocket segments using original patterns
  

While more expensive than off-the-shelf parts, custom solutions can extend the life of rare machines and preserve historical equipment.
Preventative Maintenance and Wear Management
To maximize undercarriage longevity:

• Maintain Proper Track Tension: Over-tight tracks accelerate roller and bushing wear.
  
• Clean Debris Daily: Mud and gravel trapped in the undercarriage increase abrasion.
  
• Rotate Track Pads Periodically: Even wear reduces stress on links and bolts.
  
• Use High-Quality Lubricants: Sealed and lubricated chains last longer in abrasive environments.
  

In one forestry operation, a 8B dozer extended its undercarriage life by 30% through daily cleaning and monthly pad rotation. The operator also installed bolt-on wear strips to protect the track frame.
Preserving Fiat-Allis Heritage
Despite the brand’s disappearance, Fiat-Allis machines remain in use across farms, ranches, and small construction outfits. Enthusiasts and restorers continue to maintain these machines, often fabricating parts or salvaging components from donor units.
In 2019, a vintage equipment show in Indiana featured a fully restored 8B with a custom-built blade and rebuilt undercarriage. The owner sourced parts from three different states and used a combination of Berco rollers and locally machined idlers. The machine drew attention not just for its performance, but for the dedication behind its preservation.
Conclusion
Sourcing undercarriage parts for the Fiat-Allis 8B dozer requires persistence, measurement accuracy, and a willingness to explore aftermarket and salvage options. While OEM support has vanished, a network of suppliers, machinists, and enthusiasts keeps these machines alive. With proper care and creative sourcing, the 8B can continue working—and inspiring—for decades to come.