Replacing Track Adjusting Rod in Caterpillar 953

[MikePhua]

Introduction
The Caterpillar 953 is a reliable track-type loader widely used in construction, mining, and forestry applications. Developed in the 1970s and 1980s, the 953 series became popular due to its robust undercarriage, durable engine, and high maneuverability in tough terrains. Despite its durability, components like the track adjusting rod require attention over time to ensure proper track tension and machine performance. Improper track tension can lead to accelerated wear, reduced traction, and higher maintenance costs. Understanding the replacement process of the track adjusting rod helps operators maintain productivity and reduce downtime.
Function of the Track Adjusting Rod
The track adjusting rod is a critical component of the undercarriage system. It maintains the correct tension of the tracks by controlling the position of the idler wheel. Proper track tension ensures smooth operation, prevents derailing, and minimizes excessive wear on track links and rollers. If the rod fails or becomes worn, track sagging or over-tightening can occur, negatively impacting the machine's efficiency and increasing fuel consumption.
Common Causes of Track Adjusting Rod Wear

1. Operational Stress
   Continuous operation in rugged terrain exerts pressure on the undercarriage components. The adjusting rod can bend or develop play over time.
   
2. Corrosion and Rust
   Exposure to moisture, mud, and chemicals can accelerate corrosion, weakening the rod and associated hardware.
   
3. Improper Maintenance
   Lack of lubrication or irregular inspection can result in premature wear of bushings, pins, and rod ends.
   
4. Accidental Damage
   Striking obstacles like rocks or debris can bend the rod, misalign the idler, and affect track tension.
   

Tools and Safety Equipment Required

• Hydraulic jacks or lift equipment to support the machine
  
• Wrenches and socket sets compatible with Caterpillar specifications
  
• Hammer and drift pins for bushing removal
  
• Torque wrench to ensure proper tightening of fasteners
  
• Personal protective equipment including gloves, eye protection, and steel-toed boots
  

Step-by-Step Replacement Process

1. Preparation
   Park the loader on a level surface and engage the parking brake. Disconnect the battery to prevent accidental machine movement.
   
2. Relieve Track Tension
   Drain hydraulic pressure or manually retract the idler using jacks to create slack in the track. This allows safe removal of the adjusting rod without overstressing the undercarriage.
   
3. Remove Fasteners
   Carefully remove bolts, pins, and any retaining clips securing the track adjusting rod. Keep all hardware organized for reassembly.
   
4. Extract the Rod
   Use a combination of hydraulic lift and manual tools to slide out the worn rod. Inspect surrounding bushings and idler components for wear or damage, replacing as necessary.
   
5. Install the New Rod
   Align the new track adjusting rod with the idler and mounting points. Carefully insert it without forcing, ensuring it seats properly in the bushings.
   
6. Reattach Hardware
   Reinstall pins, bolts, and retaining clips, tightening to Caterpillar torque specifications. Verify that all connections are secure.
   
7. Reapply Track Tension
   Adjust the idler to the correct tension according to the operator’s manual. Measure sag if necessary, aiming for the recommended 25–35 mm for the 953 series.
   
8. Test Operation
   Start the machine and move it slowly, observing track behavior. Check for unusual noises, misalignment, or uneven tension. Make minor adjustments as needed.
   

Tips and Recommendations

• Regularly inspect track tension and adjusting rods to prevent unexpected failures.
  
• Apply corrosion-resistant grease to rod ends and bushings to extend service life.
  
• Maintain an undercarriage maintenance log to track rod replacements and adjustments.
  
• Always use genuine or high-quality replacement parts to ensure proper fit and longevity.
  

Conclusion
Replacing the track adjusting rod on a Caterpillar 953 is a crucial maintenance procedure to maintain track tension, extend undercarriage life, and ensure safe, efficient operation. By following proper procedures, using the correct tools, and performing routine inspections, operators can minimize downtime and avoid costly repairs. The 953 series, with its rugged design, continues to serve in demanding work environments, and meticulous maintenance of components like the track adjusting rod preserves its reliability and performance.