Understanding the John Deere 35D Excavator's Low-Speed Travel Issue

[MikePhua]

The John Deere 35D compact excavator, renowned for its versatility and reliability, is equipped with a two-speed travel system that allows operators to switch between high-speed (rabbit) and low-speed (turtle) modes. This feature is essential for maneuvering in various terrains and optimizing fuel efficiency. However, some operators have reported issues where the machine remains stuck in low-speed mode, even when the switch is engaged. This article delves into the potential causes of this problem and offers insights into troubleshooting and resolution.
Common Causes of Stuck Low-Speed Mode

1. Faulty Two-Speed Switch
   

The two-speed switch, located on the operator's console, is responsible for toggling between travel speeds. A malfunction in this switch can prevent the system from recognizing the change, causing the machine to remain in low-speed mode. Visual inspection for any signs of wear or damage is recommended.

1. Electrical Issues
   

The two-speed system relies on electrical signals to function correctly. Loose or corroded wiring connections can disrupt these signals, leading to the system defaulting to low-speed mode. Inspecting and cleaning all related electrical connections can help resolve this issue.

1. Solenoid Valve Malfunction
   

The solenoid valve controls the hydraulic flow that determines the travel speed. If the solenoid valve becomes clogged or fails, it can restrict hydraulic flow, causing the machine to remain in low-speed mode. Cleaning or replacing the solenoid valve may be necessary.

1. Hydraulic System Contamination
   

Debris or contaminants in the hydraulic system can obstruct the flow of hydraulic fluid, affecting the performance of the two-speed system. Regular maintenance, including changing filters and flushing the system, can prevent such issues.
Troubleshooting Steps

1. Inspect the Two-Speed Switch
   

Begin by checking the two-speed switch for any visible signs of damage or wear. Ensure that it is functioning correctly and making proper contact.

1. Check Electrical Connections
   

Examine all electrical connections related to the two-speed system for looseness or corrosion. Clean and tighten connections as needed.

1. Test the Solenoid Valve
   

Listen for any unusual noises when the two-speed switch is engaged. A hissing sound may indicate a problem with the solenoid valve. If suspected, the valve should be cleaned or replaced.

1. Flush the Hydraulic System
   

If contamination is suspected, flush the hydraulic system to remove any debris. Replace filters and check for any blockages in the lines.
Preventive Maintenance Tips

• Regular Inspection
  

Conduct routine inspections of the two-speed system components to identify potential issues before they become major problems.

• Hydraulic Fluid Maintenance
  

Regularly check and replace hydraulic fluid to ensure optimal performance of the two-speed system.

• Electrical System Care
  

Keep electrical connections clean and secure to prevent signal disruptions.
Conclusion
The John Deere 35D's two-speed travel system is a vital feature that enhances its operational efficiency. Understanding the potential causes of issues like being stuck in low-speed mode and implementing regular maintenance can ensure the longevity and reliability of the machine. By following the troubleshooting steps and preventive maintenance tips outlined above, operators can address and prevent such issues, keeping their equipment in optimal working condition.