Deere 850K Track Issues and Solutions

[MikePhua]

The John Deere 850K dozer is a powerful and reliable piece of machinery that’s used extensively in heavy construction, land clearing, mining, and other industries. Known for its exceptional performance, durability, and efficient operation, the 850K is a popular choice for contractors and operators. However, like all heavy equipment, the 850K can experience issues over time, and one of the more common problems is related to the track system, including "onion" or "potato" bulges in the tracks.
In this article, we will explore the track issues related to the John Deere 850K, particularly the "onion" track bulge phenomenon. We’ll look at the potential causes, how to diagnose the problem, and the best solutions to ensure your machine operates smoothly and efficiently.
Overview of the John Deere 850K Crawler Dozer
The John Deere 850K is part of the K-Series line of bulldozers from Deere, designed to offer powerful performance, greater fuel efficiency, and advanced operator comfort. It’s equipped with a 9.0L, 6-cylinder engine producing around 270 horsepower, making it ideal for tough applications such as grading, pushing, and digging in challenging terrains.
Some notable features of the 850K include:

• Hydrostatic Transmission: Offers precise control and high efficiency in various working conditions.
  
• Advanced Hydraulics: High-efficiency hydraulics ensure maximum lift and dozing power.
  
• Heavy Duty Undercarriage: Built for durability and to withstand the rigors of heavy digging and pushing.
  

With these features, the 850K is a versatile machine, but problems such as track issues can quickly affect its performance and productivity.
What is "Onion" or "Potato" Bulging in Tracks?
Track bulging, often referred to as "onion" or "potato" bulging, is a phenomenon where a noticeable bump or bulge appears on the surface of the track, often causing uneven wear or making the track feel unbalanced when operating. This issue typically occurs on tracked vehicles like the John Deere 850K, and while it might seem like a minor problem at first, if left unchecked, it can lead to premature wear and expensive repairs.
This bulging occurs because of an uneven distribution of tension in the track, often caused by poor alignment or issues within the track system. While this problem is primarily cosmetic at first, it can also signal deeper issues with the undercarriage, track tensioning system, or even the sprockets or idlers.
Causes of Track "Onion" Bulging in the Deere 850K
There are several factors that can contribute to onion bulging in the tracks of the John Deere 850K. Let’s take a closer look at some of the most common causes:

1. Improper Track Tension: One of the leading causes of track bulging is improper track tension. When the tracks are too loose or too tight, they don’t operate as efficiently, and the uneven tension can cause bulging. If the tracks are too loose, the track will shift and create bulges in certain areas, whereas over-tightening can cause the track to stretch or deform.
   
2. Worn or Damaged Sprockets: The sprockets are critical components that help guide and rotate the tracks. If the sprockets are worn or damaged, they may not mesh properly with the track links, causing uneven tension and leading to bulging. Sprockets that are excessively worn can cause the track to move unevenly, creating the "onion" bulge effect.
   
3. Uneven Track Wear: If the tracks have been used in abrasive or challenging environments without proper maintenance, certain areas of the track may wear down faster than others. Uneven track wear can contribute to bulging as the worn sections of the track cause uneven distribution of force across the undercarriage system.
   
4. Track Roller and Idler Wear: Track rollers and idlers are responsible for supporting and guiding the tracks. If these components are worn out or damaged, the track may not be properly supported, leading to an uneven ride and potential bulging. Worn rollers can cause the track to shift or misalign, contributing to bulging.
   
5. Hydraulic or Suspension Issues: The track system of the 850K relies on a hydraulic tensioning system to maintain proper tension and alignment. If there’s a hydraulic leak or failure in the tensioning system, the tracks can lose their tension or become misaligned, which can lead to bulging.
   

Diagnosing Track "Onion" Bulging
If you notice any unusual bulging or irregularities in the tracks of your Deere 850K, it’s essential to diagnose the problem early to avoid further damage. Here are the steps to take for effective diagnosis:

1. Inspect Track Tension: The first step is to check the track tension. Track tension should be tight enough that the track doesn’t sag but not so tight that it causes unnecessary wear. Follow the manufacturer’s guidelines for proper track tension adjustment.
   
2. Examine the Sprockets: Inspect the sprockets for wear. If the teeth are excessively worn or misshaped, they will need to be replaced. Sprockets with missing teeth or excessive wear can lead to track misalignment and bulging.
   
3. Check for Uneven Track Wear: Inspect the track for signs of uneven wear, which can often be caused by misalignment or improper maintenance. Uneven wear may show as deeper grooves in certain areas of the track, indicating a problem with how the track is moving along the rollers or sprockets.
   
4. Inspect Track Rollers and Idlers: Rollers and idlers should be in good condition without visible signs of wear or damage. Worn or damaged rollers or idlers may cause the track to lose its proper alignment, leading to bulging.
   
5. Hydraulic System Check: If the machine uses a hydraulic system for track tension, ensure that there are no leaks or pressure issues. Insufficient pressure or hydraulic fluid loss can result in improper tensioning, which could cause bulging.
   

How to Fix and Prevent Onion Bulging
Once you’ve identified the cause of the onion bulging, it’s time to take corrective action. Here are some solutions to address the issue and prevent it from recurring:

1. Adjust Track Tension Properly: Ensure that the track tension is set correctly. Refer to the operator’s manual for the proper tensioning guidelines, and use the proper tools to adjust the tension. Regularly check track tension and adjust it as necessary.
   
2. Replace Worn Sprockets and Track Rollers: If the sprockets or rollers are worn or damaged, they should be replaced promptly. Worn sprockets can lead to poor track performance, which will affect the alignment and cause bulging. Similarly, damaged rollers should be replaced to maintain proper track guidance and alignment.
   
3. Regularly Inspect and Maintain the Track: Implement a regular inspection schedule to check for signs of uneven wear, damage, or misalignment. Routine maintenance can help prevent issues like track bulging and extend the lifespan of your undercarriage.
   
4. Hydraulic System Maintenance: Ensure that the hydraulic tensioning system is functioning correctly. Regularly check hydraulic fluid levels and inspect for leaks or other issues. Maintaining the hydraulic system will ensure the track tension is kept within proper limits.
   
5. Proper Operation: Avoid overloading the machine or using it in harsh conditions without proper maintenance. Always operate the dozer within its recommended guidelines to avoid stressing the track system and causing undue wear.
   

Conclusion
The John Deere 850K dozer is a powerful and reliable machine, but issues such as "onion" track bulging can arise if the track system is not properly maintained. Regular inspection and maintenance of the track tension, sprockets, rollers, and hydraulic systems are crucial to ensuring optimal performance. By addressing bulging early and following proper maintenance practices, you can extend the life of your tracks and minimize the risk of downtime, keeping your Deere 850K running smoothly and efficiently for years to come.