CAT 955 Pulling Issues: Troubleshooting and Solutions

[MikePhua]

The CAT 955, a versatile and powerful track loader, has been a staple in heavy machinery for decades. Known for its robust performance and exceptional versatility, the CAT 955 can tackle various tasks, from digging and lifting to grading and pushing. However, like any piece of machinery, it can experience performance issues over time. One common problem is when the loader doesn’t pull straight, which can affect its productivity and performance. This article will delve into the causes of pulling issues in the CAT 955, provide troubleshooting steps, and offer solutions for effective repairs.
Understanding the CAT 955 Track Loader
The CAT 955, introduced by Caterpillar in the mid-20th century, is a track loader designed for heavy-duty tasks. It has been favored for its ability to maneuver in challenging terrain and deliver high operational efficiency. Whether used in construction, mining, or agricultural applications, the CAT 955 has seen widespread use. The loader's design incorporates a hydrostatic transmission system, allowing for smooth control over the drive and work hydraulics.
However, like any machine operating in demanding conditions, the CAT 955 can face issues, especially as it ages. One common issue that can occur is when the loader starts to "pull" or veer off in a direction, either left or right, while being driven. This issue can be annoying and challenging, particularly when precision is needed on the job site.
Common Causes of Pulling Issues in the CAT 955
When a track loader like the CAT 955 starts pulling to one side, there are several potential causes. It’s essential to address these problems early, as they can lead to further damage or reduce operational efficiency.
1. Uneven Track Tension
Uneven track tension is one of the most common causes of pulling in a track loader. If the tracks are not evenly tensioned on both sides, one track may be tighter than the other, causing the machine to pull to one side. Over time, if left unchecked, this can lead to premature wear of the tracks and undercarriage components.

• Symptoms: The loader pulls in one direction, often with a noticeable shift in movement to one side.
  
• Potential Causes: Improper adjustment of track tension or wear in one of the track rollers.
  

2. Track Wear and Damage
Uneven wear or damage to the tracks can also cause a loader to pull in one direction. If one track is worn more than the other, or if the tracks are damaged by rocks, debris, or rough terrain, the machine will not maintain a straight path.

• Symptoms: The loader veers to one side, and there may be noticeable damage or wear on one side of the tracks.
  
• Potential Causes: Worn-out track lugs, broken track links, or excessive wear on one side of the track.
  

3. Imbalanced or Misaligned Undercarriage
The undercarriage plays a critical role in ensuring that the machine operates smoothly. If the undercarriage is misaligned, damaged, or improperly installed, it can lead to pulling issues. This could happen due to wear on the drive sprocket or other undercarriage components.

• Symptoms: The loader moves erratically or fails to maintain a straight path, with visible wear on the undercarriage.
  
• Potential Causes: Misalignment of the undercarriage, uneven wear of the sprockets, or damaged drive components.
  

4. Hydraulic or Transmission Issues
The CAT 955 relies on hydraulic and transmission systems to control its movement. If there is a malfunction in the hydraulic pumps, cylinders, or the transmission, it can cause the machine to pull to one side. This is usually accompanied by other symptoms, such as erratic movement or a delay in response.

• Symptoms: The loader pulls to one side and may also experience sluggish movement or difficulty maintaining speed.
  
• Potential Causes: Hydraulic fluid leaks, low hydraulic pressure, or malfunctioning hydraulic components. Transmission issues, such as low fluid levels or a failing pump, can also contribute.
  

5. Improper Weight Distribution
In some cases, an imbalanced load or improper weight distribution can cause the loader to pull to one side. This typically occurs when the loader is carrying a load that is not centered properly or when the machine is loaded unevenly.

• Symptoms: The loader veers in one direction when carrying a load.
  
• Potential Causes: Unbalanced load, uneven weight distribution, or improper attachment positioning.
  

Troubleshooting Pulling Issues
When the CAT 955 starts pulling in one direction, there are several steps that operators and mechanics can take to identify the root cause.
1. Check the Track Tension
Begin by inspecting the track tension on both sides of the machine. Uneven tension can easily be identified by comparing the tension of the tracks. Ensure that both tracks are adjusted according to the manufacturer’s recommendations.

• Action: Use a track tension gauge to check the tension of both tracks. If one side is too tight or too loose, adjust the tension accordingly.
  

2. Inspect the Tracks for Wear
Next, visually inspect the tracks for any uneven wear or damage. Look for signs of excessive wear on one side or any missing track lugs. If damage is found, it may be necessary to replace the tracks or repair the damaged links.

• Action: Measure the tread wear and inspect the track links for signs of damage. If uneven wear is found, replace the tracks or adjust the machine's operation to prevent further damage.
  

3. Examine the Undercarriage
Misalignment or excessive wear in the undercarriage components can cause pulling. Check the condition of the drive sprockets, rollers, and other undercarriage parts. Ensure everything is properly aligned and functioning.

• Action: Inspect the drive sprockets, rollers, and undercarriage alignment. If misalignment or wear is found, repair or replace the affected components.
  

4. Test Hydraulic and Transmission Systems
If the problem appears to be related to the machine's movement and responsiveness, test the hydraulic and transmission systems. Check for any fluid leaks, low hydraulic pressure, or malfunctioning components that may be contributing to the pulling issue.

• Action: Inspect the hydraulic system for leaks, low fluid levels, or malfunctioning components. Test the transmission for smooth shifting and proper fluid levels.
  

5. Rebalance the Load
If the pulling issue occurs when the machine is carrying a load, check the load distribution. Ensure that the load is centered and evenly distributed to prevent the machine from pulling to one side.

• Action: Reposition the load to ensure that it is balanced. Avoid overloading one side of the loader.
  

Solutions and Preventative Maintenance
1. Track and Tension Adjustments
Proper track maintenance, including correct tension, is essential for smooth operation. Regularly monitor track tension and adjust as needed to prevent uneven wear.
2. Undercarriage Maintenance
Inspect the undercarriage regularly to ensure that all components are in good condition. Replace worn sprockets, rollers, and idlers as necessary to maintain proper alignment and performance.
3. Hydraulic System Maintenance
Regularly check the hydraulic fluid levels and inspect the system for leaks. A well-maintained hydraulic system is key to preventing transmission issues that can cause pulling.
4. Regular Track Inspections
Frequent inspections of the tracks for wear and damage can prevent more severe issues. Replace tracks or track components as soon as wear becomes noticeable to avoid pulling problems.
5. Weight Distribution
Always ensure that the loader is carrying a balanced load, and avoid placing uneven weight on one side of the machine. Proper loading and unloading practices can help prevent pulling caused by weight imbalance.
Conclusion
When a CAT 955 starts pulling to one side, it can be a sign of several potential issues, including uneven track tension, worn tracks, hydraulic malfunctions, or undercarriage problems. By carefully diagnosing and addressing the issue through systematic inspection, operators can resolve pulling problems and keep their machines running smoothly.
By maintaining regular checks on the machine's tracks, undercarriage, hydraulic system, and weight distribution, owners and operators can avoid costly repairs and prolong the life of their CAT 955. Proper maintenance and attention to detail are the keys to ensuring that the machine continues to perform at its best.