Differences Between CAT 941 and 941B Track Loaders

[MikePhua]

Caterpillar’s Legacy in Track Loaders
Caterpillar introduced the 941 track loader in the late 1960s as part of its expanding lineup of crawler-based earthmoving equipment. Designed to bridge the gap between dozers and wheel loaders, the 941 offered versatility in digging, loading, and grading tasks. It quickly became a staple on construction sites and in agricultural applications. The 941B, released in the mid-1970s, was a refined successor with improved powertrain components and structural upgrades. Together, these models contributed to Caterpillar’s dominance in the track loader market, with thousands sold across North America and Europe.
Radiator and Cooling System Changes
One of the most noticeable differences between the 941 and 941B is the radiator design. The original 941 featured a simpler core, while the 941B incorporated a transmission cooler section integrated into the radiator assembly. This change was driven by the increased horsepower and heat load of the updated drivetrain. While some operators have attempted to swap radiators between the two models, the core dimensions and guard structures differ significantly, making direct interchangeability impractical without custom fabrication.
In one case, a technician attempted to transplant the entire nose assembly from a 941 to a 941B to retain the superior cooling performance. However, mismatched part numbers and mounting points complicated the process. The takeaway: while the idea of swapping parts between generations is tempting, the engineering differences often require more than bolt-on solutions.
Transmission and Steering Configurations
Both the 941 and 941B use torque converter/powershift transmissions, but the internal gearing and steering mechanisms evolved between models. The 941 was offered with either lever or pedal steering, while the 941B standardized pedal steering with 14-bolt clutch drums. This change improved responsiveness and reduced operator fatigue.
Transmission options also varied. The earlier 941 had three possible configurations, while the 941B narrowed it to two—both of which overlapped with the 941’s offerings. However, without access to original build sheets, identifying the exact transmission installed in a given unit is difficult. Caterpillar’s legacy support systems once provided detailed arrangement data, but newer digital platforms have phased out configuration records for older machines.
Final Drive and Gear Ratio Differences
The final drives underwent a significant redesign between the two models. The 941 used a 10-tooth transmission pinion and a 58-tooth bull gear, while the 941B featured a 9-tooth pinion and a 52-tooth bull gear. These changes altered torque delivery and were paired with a revised bevel gear and pinion set in the cross shaft assembly. The goal was to accommodate the increased engine output and improve mechanical efficiency.
Attempting to swap final drives between the two models is risky. Mismatched gear ratios can lead to catastrophic failures, including cracked main cases and stripped gears. One experienced mechanic warned that mixing components could result in misalignment and uneven load distribution, especially under heavy use.
Sheet Metal and Structural Variations
Beyond mechanical components, the 941B introduced several sheet metal upgrades. The front grill plate was redesigned with fewer perforations to reduce dirt ingress, and the lower side plates were made from thicker steel for added durability. The fuse box location also shifted, moving to the opposite side of the kick plate for easier access.
These changes, while subtle, reflect Caterpillar’s ongoing efforts to improve serviceability and longevity. Operators working in dusty or abrasive environments appreciated the reduced maintenance burden and improved protection.
Shared Components and Cross-Model Compatibility
Despite the differences, some parts remain interchangeable. Roller frames, track guards, and certain sheet metal panels can be swapped between the 941 and 941B with minimal modification. Additionally, the 951C and D4E models share transmission and final drive components with the 941B, offering a broader pool of salvageable parts for repairs.
This cross-compatibility has helped keep older machines running, especially in regions where parts availability is limited. In one instance, a rural contractor rebuilt a 941B using donor parts from a retired 951C, saving thousands in replacement costs.
Terminology Clarification

• Torque Converter: A fluid coupling that transmits engine power to the transmission, allowing smooth gear changes under load
  
• Powershift Transmission: A type of transmission that allows gear changes without manual clutching, using hydraulic actuators
  
• Bull Gear: A large gear in the final drive that transmits torque to the track
  
• Pinion Gear: A smaller gear that meshes with the bull gear to drive the final assembly
  
• Bevel Gear: A gear that changes the direction of power flow, typically used in cross shafts
  

Recommendations for Owners and Restorers
When working with legacy Caterpillar track loaders, consider the following:

• Always verify part numbers before attempting swaps
  
• Use parts books and physical measurements to confirm compatibility
  
• Avoid mixing final drive components across models
  
• Retain original gear ratios to prevent drivetrain stress
  
• Salvage shared components from compatible models like the 951C
  

Final Thoughts
The CAT 941 and 941B represent two generations of rugged, reliable track loaders that helped shape modern earthmoving practices. While they share a common lineage, their mechanical differences demand careful attention during repairs and restorations. With thoughtful planning and respect for engineering nuances, these machines can continue to serve for decades—testament to Caterpillar’s enduring legacy in heavy equipment design.