Removing the Track Adjuster on a Caterpillar 955L Requires Force, Finesse, and Clean Technique

[MikePhua]

The Legacy of the Caterpillar 955L Track Loader
The Caterpillar 955L was introduced in the early 1970s as part of Cat’s evolution in crawler loaders. Built for rugged excavation, demolition, and material handling, the 955L featured a 13X1 serial prefix and was powered by the reliable Cat 3304 engine. With an operating weight of over 30,000 pounds and a bucket capacity exceeding 2 cubic yards, it became a staple in construction fleets across North America and beyond.
Its undercarriage system, including the track adjusters, was designed for durability but required regular maintenance. The track adjuster assembly plays a vital role in maintaining proper track tension, which affects traction, wear, and fuel efficiency. Over time, corrosion, debris, and hydraulic pressure can make removal a challenge.
Terminology Notes

• Track adjuster: A hydraulic or spring-loaded mechanism that maintains track tension by pushing the idler forward.
  
• Idler: The front wheel in the track system that guides and supports the track chain.
  
• Yoke: The bracket that connects the idler to the adjuster piston.
  
• Grease fitting: A port used to inject grease into the adjuster cylinder to build pressure.
  
• Recoil spring: A heavy-duty spring that absorbs shock and maintains tension in older mechanical systems.
  

Preparation Before Removal
Before attempting removal:

• Park the machine on level ground and block the tracks
  
• Clean the adjuster area thoroughly to expose bolts and fittings
  
• Release hydraulic pressure by removing the grease fitting and bleeding the cylinder
  
• Use a pry bar or track jack to relieve tension on the idler
  
• Inspect the yoke and cylinder for rust, cracks, or deformation
  

If the adjuster is seized, apply penetrating oil and allow time for it to work. Avoid hammering directly on the cylinder or yoke, as this can cause structural damage.
A Story from the Red River Basin
In 2009, a contractor in Manitoba attempted to remove the track adjuster on a 955L that had sat idle for five years. The grease fitting was clogged, and the cylinder was packed with hardened clay. After soaking the assembly with rust penetrant and using a hydraulic spreader to push the idler back, the crew finally freed the adjuster. They replaced the seals and reinstalled the unit with fresh grease. The operator said, “It took patience and pressure—not brute force.”
Disassembly Steps and Safety Tips
To remove the adjuster:

• Remove the track chain from the idler using a track press or by separating the master link
  
• Unbolt the yoke from the idler frame
  
• Extract the adjuster cylinder from the recoil housing
  
• Inspect the piston rod for scoring or bending
  
• Replace seals, bushings, and the grease fitting if worn
  

Safety tips:

• Wear eye protection when releasing grease pressure
  
• Use cribbing to support the idler during removal
  
• Avoid standing in the recoil path of the spring
  
• Use torque specs when reinstalling bolts and fittings
  

If the recoil spring is part of the assembly, treat it with caution—it stores significant energy and can cause injury if mishandled.
Reinstallation and Adjustment Procedure
To reinstall:

• Clean all mating surfaces and apply anti-seize to bolts
  
• Insert the adjuster cylinder and align the yoke with the idler
  
• Torque bolts to manufacturer specifications
  
• Inject grease slowly until the track achieves proper sag (typically 1–2 inches between the carrier roller and track)
  
• Cycle the machine forward and backward to settle the track
  

Monitor tension during the first few hours of operation. Over-tightening can accelerate wear on rollers and sprockets, while under-tightening can cause derailment.
Preventive Maintenance and Long-Term Care
To extend adjuster life:

• Inspect grease fittings monthly and keep them clean
  
• Check track tension weekly in high-use environments
  
• Flush debris from the adjuster housing during undercarriage cleaning
  
• Replace seals every 2,000–3,000 hours or during major service
  
• Use high-quality grease rated for heavy equipment
  

Some operators retrofit zerk guards or install remote grease lines for easier access. Others add tension indicators to monitor sag visually.
Final Thoughts
Removing and servicing the track adjuster on a Caterpillar 955L is a task that blends mechanical knowledge with field-tested technique. With proper preparation, clean tools, and respect for the forces involved, even a seized adjuster can be restored to full function. In the world of tracked machines, tension is everything—and the adjuster is the silent guardian that keeps steel moving forward.