Troubleshooting Track Banging on John Deere 850J and 750J Dozers

[MikePhua]

When operating heavy equipment like the John Deere 850J and 750J dozers, one of the most frustrating issues operators can encounter is the "banging" or "clunking" noise coming from the tracks. This problem is not only irritating but could also indicate underlying mechanical issues that need to be addressed to avoid further damage or performance loss. Understanding the cause of this issue and how to fix it is crucial for maintaining the optimal performance of these dozers.
This article delves into the potential causes of track banging on the John Deere 850J and 750J dozers, along with diagnostic methods, solutions, and preventive measures to ensure the longevity of the tracks and the overall equipment.
Common Causes of Track Banging on Dozers
Track banging on dozers is often a result of misalignment, loose components, or wear and tear. Below are some of the most common reasons why you might experience this problem:
1. Track Tension Issues
Track tension plays a significant role in the overall operation of dozer tracks. If the tracks are too loose or too tight, they can cause a banging sound as they move over the rollers, sprockets, and other components.

• Loose Tracks: If the track is too loose, the track pads may hit the track frame, rollers, and the undercarriage, creating a banging or clunking sound. Loose tracks also increase the risk of derailing, which can lead to further damage.
  
• Over-Tightened Tracks: If the track is too tight, it will create excessive tension on the track components, leading to premature wear of the sprockets, rollers, and idlers. This can cause a repetitive knocking or banging noise as the components strain under pressure.
  

Solution: Always check the track tension regularly using the manufacturer’s specifications. The tracks should be tensioned to the recommended settings for optimal performance and safety. Use the correct tools to measure tension and make adjustments as necessary.
2. Worn or Damaged Rollers and Idlers
Rollers and idlers play a critical role in the smooth movement of the tracks. Worn or damaged rollers can cause irregular contact between the track and the machine, resulting in clunking or banging sounds.

• Worn Rollers: Over time, rollers can become worn out due to constant contact with the tracks. This wear can cause the rollers to become misshapen or out of alignment, creating an uneven surface for the tracks to travel over.
  
• Damaged Idlers: Idlers help guide the tracks around the drive sprockets. If the idlers are damaged or have excessive wear, the tracks may not run smoothly, and this can cause banging or clunking sounds.
  

Solution: Inspect the rollers and idlers for signs of wear, such as pitting, uneven surfaces, or excessive play. If they appear worn or damaged, they should be replaced immediately to prevent further damage to the tracks and undercarriage.
3. Track Pad Wear and Misalignment
Track pads are designed to make contact with the ground, providing traction and stability. However, if the track pads are worn unevenly or misaligned, they can cause the track to jump or bang against the frame as the dozer moves.

• Uneven Track Pad Wear: This occurs when some pads wear down more quickly than others due to improper use or poor maintenance. This can lead to an unbalanced track that may cause noise or a bumpy ride.
  
• Misalignment of Track Pads: Track pads that are not properly aligned with the tracks can cause the tracks to shift or jump as they move over the rollers and sprockets. This misalignment can result in a repetitive banging sound, especially when moving at higher speeds.
  

Solution: Check the track pads for even wear and proper alignment. Replace any worn or misaligned track pads. Track alignment should be adjusted during regular maintenance intervals to prevent any issues from arising.
4. Sprocket Wear and Misalignment
The sprockets play a crucial role in the movement of the tracks. They engage with the track links to propel the machine forward. Worn or misaligned sprockets can cause jerky movement and noise.

• Worn Sprockets: Sprockets can wear out over time due to constant engagement with the track links. If the teeth on the sprockets become worn or chipped, they will no longer mesh smoothly with the track links, resulting in a banging or clunking noise.
  
• Sprocket Misalignment: If the sprockets are misaligned, they will not engage the track links properly, which can lead to uneven movement and excessive noise.
  

Solution: Inspect the sprockets for wear and misalignment. If the teeth are damaged or worn down, the sprockets should be replaced. Regular maintenance and alignment checks will help prevent issues with the sprockets.
5. Track Link Wear and Pin Failure
Track links and the pins that connect them are essential components for maintaining track movement. Over time, the pins can wear out or fail, causing a gap between the links, which results in the tracks clunking or banging against the undercarriage.

• Track Link Wear: Track links wear down over time due to constant movement and friction. If the links become excessively worn, they may not fit properly, causing them to hit or rub against other components.
  
• Pin Wear or Failure: The pins that connect the track links can wear out or even fail, causing a loss of flexibility and improper track movement. This can lead to jerking or banging noises as the machine moves.
  

Solution: Inspect the track links and pins for signs of wear. If the pins are loose, worn, or damaged, replace them immediately. Proper lubrication and maintenance can help extend the life of the track links and pins.
6. Lack of Lubrication or Poor Maintenance Practices
Regular lubrication is essential for the smooth operation of the track system. Lack of proper lubrication can lead to increased friction, wear, and banging noises as the tracks move.

• Dry Components: If the rollers, idlers, or track links are not properly lubricated, they can wear out prematurely, leading to excess play and noise.
  
• Poor Maintenance Practices: Skipping regular maintenance, such as track inspection, tightening, and lubrication, can cause small issues to escalate into more significant problems.
  

Solution: Ensure that all track components are properly lubricated at regular intervals. Follow the manufacturer's guidelines for maintenance and lubrication. Regular maintenance checks will help identify issues before they cause extensive damage.
7. Track Component Compatibility
If the tracks, rollers, or sprockets are replaced with incompatible parts, this can result in poor performance and excessive noise. It’s essential to use the correct parts that match the machine’s specifications.

• Incompatible Parts: Using non-genuine or incorrectly sized components can cause alignment issues, leading to banging noises as the machine operates.
  

Solution: When replacing parts, always use OEM (Original Equipment Manufacturer) or equivalent components. Ensure that they are compatible with your specific model of the John Deere dozer.
Preventive Measures to Avoid Track Banging
To prevent track banging and ensure the longevity of your John Deere 850J or 750J dozer, follow these preventive measures:

1. Regular Track Inspections: Perform routine inspections of the tracks, rollers, sprockets, and undercarriage components. Look for signs of wear, misalignment, or damage.
   
2. Proper Track Tension: Maintain the correct track tension according to the manufacturer’s specifications. This ensures the tracks operate smoothly and reduces the risk of banging.
   
3. Frequent Lubrication: Keep all moving components properly lubricated to minimize friction and prevent premature wear.
   
4. Proper Track Alignment: Ensure that the track pads are aligned and evenly worn. Misalignment can cause the tracks to jump, resulting in noise and potential damage.
   
5. Use Quality Parts: Always use high-quality replacement parts that are compatible with your machine. This will help avoid issues with misalignment, wear, or improper fitting.
   

Conclusion
Track banging on John Deere 850J and 750J dozers is often a sign of underlying issues with the track system, such as poor track tension, worn rollers, misaligned track pads, or damaged sprockets. By understanding the causes of these problems and taking proactive steps for diagnosis and maintenance, operators can keep their machines running smoothly, avoid costly repairs, and extend the life of their dozers.
Regular inspections, timely repairs, and proper maintenance practices are essential to ensure that your John Deere dozer remains in peak condition, minimizing downtime and maximizing productivity on the job site.