Restoring a 1958 Cat 933 Traxcavator and Sourcing Obsolete Components

[MikePhua]

Quick answer
The 1958 Caterpillar 933 Traxcavator (serial prefix 11A) remains a viable restoration project, but sourcing obsolete parts like top carrier rollers and fuel pump kits requires a mix of aftermarket suppliers, salvage yards, and fabrication. With careful matching of serial numbers and part codes, even rare bronze-bushing rollers can be rebuilt or replaced.
Cat 933 Traxcavator development and legacy
The Caterpillar 933 was introduced in the mid-1950s as a compact track loader designed for grading, excavation, and material handling. Built on a crawler tractor platform, the 933 featured:

• A direct-injection diesel engine (D311 or D315 depending on year)
  
• Mechanical transmission with clutch and gear drive
  
• Hydraulic loader arms and bucket
  
• Steel undercarriage with carrier rollers and track pads
  

The 11A serial prefix identifies early production units, often equipped with bronze-bushing carrier rollers and mechanical fuel pumps. These machines were widely used in forestry, roadwork, and small-scale construction, especially in rural North America.
Common restoration needs and part sourcing
Owners restoring a 933 often face challenges locating:

• Top carrier rollers: Early bronze-bushing style, often obsolete in dealer catalogs
  
• Transfer fuel pump repair kits: Diaphragm failure leads to fuel leakage from relief tubes
  
• Track pads and skid plates: Subject to wear and corrosion
  
• Hydraulic seals and hoses: Often dry-rotted or cracked from age
  

While Caterpillar dealers may list these parts as obsolete, several strategies can help:

• Aftermarket undercarriage suppliers: Brands like TREK, ITP, and ITR offer compatible rollers and pads if part numbers and dimensions are known
  
• Salvage yards: Regional yards may stock dismantled 933s or NOS (new old stock) components
  
• Online part databases: Searching by part number can reveal hidden inventory or surplus listings
  
• Fabrication shops: Rollers and plates can be rebuilt or machined if original specs are available
  

One user located a roller through a Virginia-based yard known for older Cat inventory, while another sourced a diaphragm kit from a Birmingham supplier specializing in vintage fuel systems.
Serial number importance and compatibility
Matching parts to the correct serial number is critical. The 933 underwent several design changes across its production run, affecting:

• Roller dimensions and bushing type
  
• Fuel pump mounting and diaphragm style
  
• Track pad bolt patterns
  
• Loader arm geometry
  

Before ordering, owners should:

• Record the full serial number from the transmission housing
  
• Cross-reference with parts manuals or Cat Classic catalogs
  
• Confirm compatibility with aftermarket suppliers
  

Use case and restoration strategy
In this case, the machine is used seasonally at a Maine camp for light forestry work. For hobby-grade use, rebuilt or aftermarket parts are often sufficient. However, used components from unknown machines may be worn or incompatible.
Recommendations:

• Prioritize new or rebuilt rollers over used ones to avoid premature failure
  
• Install magnets in the final drive housing to capture metal debris
  
• Replace fuel pump diaphragms proactively to prevent leaks and fire risk
  
• Use Cat Classic parts when available, as they often match or exceed salvage pricing
  

Conclusion
Restoring a 1958 Cat 933 Traxcavator is a rewarding challenge that blends mechanical skill with historical preservation. While some parts are obsolete, creative sourcing and community knowledge make it possible to keep these machines running. With proper attention to serial numbers and part specs, even rare components like bronze-bushing rollers and fuel pump kits can be found or rebuilt.