Deere 670B Will Not Move: Troubleshooting and Solutions

[MikePhua]

The John Deere 670B is a mid-sized dozer that has been a reliable workhorse for construction, mining, and land-clearing operations. Known for its durable build and powerful performance, the 670B is a favorite among operators in need of a versatile machine capable of handling tough terrains. However, like any piece of heavy equipment, the 670B can experience mechanical issues that hinder its performance. One of the most concerning problems an operator might encounter is when the dozer refuses to move, despite the engine running smoothly.
In this article, we will explore common reasons why the Deere 670B might not move and offer practical solutions to troubleshoot and resolve these issues.
Understanding the John Deere 670B
The Deere 670B is a crawler dozer that features a hydrostatic transmission system, which provides smooth power delivery to the tracks, enabling the machine to move easily across different surfaces. Its key features include:

• Engine Type: Typically powered by a 6.8L John Deere engine, producing around 90-100 horsepower.
  
• Operating Weight: Around 18,000 lbs.
  
• Transmission: Hydrostatic, which eliminates the need for a manual gearshift and allows for variable speed control without interruption.
  
• Blade Options: Available with a variety of blade configurations for grading, pushing, and lifting.
  

This dozer is designed for tough tasks, and its rugged design makes it suitable for both urban construction sites and rural land development. The hydrostatic transmission system is an important part of the machine's drive system, as it controls the movement and speed. If this system malfunctions, the dozer can experience significant operational issues.
Common Reasons Why the Deere 670B Won’t Move
When a Deere 670B refuses to move, it could be due to several different mechanical failures. The cause can range from simple problems like a fluid leak or electrical failure to more complex issues such as a malfunctioning transmission. Below are some of the most common reasons why the 670B might not move:

1. Hydrostatic Transmission Failure
   The hydrostatic transmission is responsible for the machine’s ability to move. If there is an issue with this system, such as low fluid levels, a fluid leak, or a malfunctioning pump, the machine may fail to move. Common symptoms of a hydrostatic transmission problem include the engine running, but no power is being transferred to the tracks.
   
2. Low Hydraulic Fluid
   Both the transmission and the tracks rely on hydraulic fluid to function properly. If the hydraulic fluid is low or contaminated, it can cause the system to fail. This can result in a loss of movement, erratic movements, or a complete lack of motion. Low fluid levels might also cause overheating in the hydraulic system.
   
3. Faulty Drive Motors or Pump
   The drive motors and pump in the 670B are crucial to the movement of the machine. If these components fail or become worn, the machine may not move. This can be especially true for older dozers or those that have undergone heavy usage.
   
4. Electrical System Issues
   Electrical problems such as a faulty starter motor, bad connections, or damaged wiring can also prevent the dozer from moving. The Deere 670B relies on electrical systems to start the engine and engage the transmission. If there’s an electrical failure, the machine may not operate as intended.
   
5. Damaged Tracks or Undercarriage
   While less common, issues with the undercarriage or damaged tracks can also prevent the machine from moving. If the tracks are severely damaged or if there is a significant issue with the drive sprockets, the dozer may struggle to move.
   
6. Engine Power Loss
   Although the engine may run, a loss of power or poor fuel quality can reduce the ability of the machine to move effectively. If the engine is not generating enough power, the tracks will not turn as required.
   

Troubleshooting the Deere 670B: Steps to Take
When the Deere 670B is not moving, it’s crucial to perform a thorough diagnostic to identify the root cause of the problem. Follow these steps to troubleshoot the issue:

1. Check Hydraulic Fluid Levels
   Begin by inspecting the hydraulic fluid levels. Low fluid levels are one of the most common reasons for a lack of movement in the 670B. Check the fluid reservoir and ensure that the fluid is at the correct level. If it’s low, refill the system with the recommended hydraulic fluid and test the machine again. Also, inspect for any leaks that could have caused fluid loss.
   
2. Inspect the Transmission and Hydraulic Lines
   A fluid leak in the hydrostatic transmission system or hydraulic lines can result in a loss of power. Inspect all hoses and fittings for signs of leakage or damage. If you find any issues, replace the damaged components and refill the hydraulic system with the appropriate fluid.
   
3. Test the Drive Motors
   If the fluid levels and hydraulic system appear fine, but the machine still won’t move, the next step is to check the drive motors and pump. A malfunctioning drive motor or pump can prevent the transmission system from operating properly. If you suspect a failure in these components, they may need to be serviced or replaced.
   
4. Examine the Electrical System
   Check the electrical system for any issues, such as blown fuses, damaged wiring, or a faulty starter motor. Ensure that the battery is fully charged and that the connections are secure. A weak or dead battery can also prevent the 670B from starting or moving.
   
5. Look for Track or Undercarriage Damage
   If the engine and hydraulic system are functioning correctly, inspect the tracks and undercarriage. If the tracks are worn or have become disengaged from the sprockets, it will be impossible for the dozer to move. Replace any damaged components or adjust the tracks as necessary.
   
6. Perform an Engine Diagnostic
   If everything else checks out, there may be an issue with the engine itself. Perform a diagnostic test to ensure that the engine is running at full power and that there are no issues with the fuel system. Check for any performance issues such as a rough idle, misfires, or smoke that could indicate an engine problem.
   

When to Seek Professional Help
If you’ve gone through the troubleshooting steps and the 670B still won’t move, it’s time to consult a professional mechanic or technician who specializes in John Deere equipment. Certain issues, such as a malfunctioning hydrostatic transmission or problems with the internal components of the drive motors, can be complex to fix without the proper expertise.
John Deere dealers and service centers can provide the necessary tools, knowledge, and parts required to repair the machine. Additionally, they can perform a more thorough diagnostic using specialized diagnostic equipment to pinpoint the problem.
Preventive Maintenance for the Deere 670B
To avoid future issues with the 670B not moving, it’s essential to follow a regular maintenance schedule. This includes:

• Regular fluid checks and changes: Ensure that hydraulic fluid and engine oil levels are consistently checked and replaced at the recommended intervals.
  
• Hydraulic system inspections: Inspect hoses and components for signs of wear or leaks.
  
• Engine and transmission service: Periodically inspect the engine, transmission, and related components to catch any potential issues early.
  
• Track maintenance: Regularly inspect the tracks and undercarriage for wear, adjusting as necessary.
  

By staying on top of maintenance, you can prevent many common issues from causing the dozer to stop moving, ensuring that your Deere 670B continues to perform reliably on the job site.
Conclusion
When a John Deere 670B fails to move, it can be frustrating, but the problem is often solvable with a systematic approach to troubleshooting. By carefully inspecting the hydraulic system, transmission, electrical components, and tracks, you can pinpoint the issue and make the necessary repairs. If the problem persists, seeking professional help from a John Deere service center is the best course of action. With proper maintenance and prompt repairs, your Deere 670B will continue to deliver reliable performance for years to come.