Verifying Rim Compatibility for Caterpillar Motor Graders

[MikePhua]

Caterpillar’s Grader Line and the Role of Wheel Specifications
Caterpillar motor graders have long been a cornerstone of road construction and maintenance, with models like the 120H, 140H, and 160H widely deployed across municipal fleets and private contractors. These machines rely on precise wheel and tire configurations to maintain grading accuracy, traction, and load distribution. While engine power and blade control often take center stage, rim specifications—such as bolt pattern, center bore, and width—play a critical role in ensuring safe and efficient operation.
The 14.00-R24 tire size is commonly used on mid-size graders, offering a balance between flotation and ground pressure. Matching these tires with the correct rim is essential, especially when sourcing aftermarket or take-off assemblies.
Understanding Bolt Patterns and Center Bore Dimensions
One of the most important parameters in rim compatibility is the bolt circle diameter (BCD), which defines the spacing of the lug holes. For Caterpillar graders using 10-bolt rims designed for 14.00-R24 tires, the standard bolt circle is approximately 285 mm, with a center bore of 228.85 mm. These dimensions are consistent across many OEM and aftermarket rim manufacturers, allowing for interchangeability between one-piece and three-piece rim designs.
Terminology notes:

• Bolt circle diameter (BCD): The diameter of the circle formed by the centers of the bolt holes
  
• Center bore: The diameter of the hole at the center of the rim that fits over the hub
  
• One-piece rim: A solid rim structure without removable bead rings
  
• Three-piece rim: A modular rim with separate components for easier tire mounting
  

While three-piece rims are often used in heavy-duty applications for ease of service, one-piece rims are preferred for simplicity and reduced maintenance.
Identifying Rim Origins and Cross-Application Potential
In some cases, take-off rims may originate from telehandlers or other off-road equipment. For example, OTR part number 1001091168 was identified on a set of nearly new 14.00-R24 Goodyear SG-2B tires mounted to 10-bolt rims. While the tires were clearly grader-grade, the rims may have been originally designed for telehandlers, which sometimes share similar bolt patterns but differ in offset, hub depth, or mounting style.
To confirm compatibility:

• Measure the bolt circle and center bore directly using calipers
  
• Compare rim part numbers with Caterpillar’s SIS (Service Information System) database
  
• Cross-reference with known grader rim part numbers, such as Cat 6G1527, which fits multiple models
  
• Contact rim manufacturers for application charts or fitment guides
  

If the rims match the bolt pattern and bore but differ in offset or hub depth, adapters may be theoretically possible—but practical implementation is often limited by structural constraints.
Challenges in Retrofitting and Adapter Fabrication
Retrofitting non-standard rims to a grader is rarely straightforward. Many grader hubs use a central locking nut and rim clamps rather than traditional lug bolts. This means the rim must interface with a disk that mounts separately to the hub, and the rim itself clamps onto that disk. Without bolt holes in the existing wheel disk, fabricating adapters becomes complex and potentially unsafe.
Recommendations:

• Avoid modifying structural components unless certified by an engineer
  
• Use OEM-style rims whenever possible to preserve safety and resale value
  
• If adapters are considered, ensure they meet load ratings and maintain proper offset
  
• Document all modifications for future service and inspection
  

In most cases, selling mismatched rims separately and sourcing correct grader rims is more practical than attempting retrofits.
A Story from the Field
In Alberta, a contractor purchased a set of nearly new 14.00-R24 tires with 10-bolt rims at auction, believing they were from a Caterpillar grader. Upon inspection, the rims matched the bolt circle and bore but lacked the mounting features required for his machine. After contacting the manufacturer and verifying the part number, he learned the rims were designed for a telehandler. While the tires were valuable, the rims were not compatible. He sold the rims to a local equipment dealer and used the proceeds to buy proper grader rims, ultimately saving time and avoiding costly fabrication.
Recommendations for Buyers and Sellers of Take-Off Assemblies
To ensure proper fitment and maximize resale value:

• Always verify rim part numbers and dimensions before purchase
  
• Request documentation from sellers, including machine origin and mounting style
  
• Use manufacturer databases or contact support teams for compatibility charts
  
• Inspect rims for signs of foam filling, which may affect resale and handling
  
• Consider separating tires and rims for resale if compatibility is uncertain
  

For buyers seeking to upgrade or replace grader tires, purchasing assemblies with confirmed fitment can reduce downtime and installation costs.
Conclusion
Rim specifications for Caterpillar motor graders are more than just numbers—they determine whether a tire assembly will perform safely and efficiently under demanding conditions. With bolt circle diameters, center bores, and mounting styles varying across equipment types, careful verification is essential. Whether sourcing from auctions, salvage yards, or aftermarket suppliers, understanding the nuances of rim compatibility ensures that every grader stays grounded, aligned, and ready to shape the road ahead.