Troubleshooting Jerky or Bucking Behavior in Bobcat 1835B Skid Steers

[MikePhua]

Bobcat 1835B skid steers are widely known for their versatility, robust performance, and compact design, making them a favorite for construction, landscaping, and agricultural tasks. However, like any piece of heavy equipment, these machines can develop issues over time. One common problem reported by operators is "jerky" or "bucking" behavior, which can affect their operation and overall performance. This article explores potential causes of jerky or bucking behavior in Bobcat 1835B skid steers and provides solutions and preventive measures for maintaining smooth operation.
Understanding Jerky or Bucking Behavior in Skid Steers
Jerky or bucking behavior in a skid steer refers to sudden, unexpected movements that cause the machine to lurch forward or backward in a disruptive, uneven manner. This issue can affect the machine’s ability to move smoothly, making tasks like grading, lifting, or hauling difficult and inefficient.
These symptoms can vary from minor jolts when operating at low speeds to more pronounced bucking during acceleration or when attempting to lift heavy loads. Identifying the root cause of this behavior is critical, as it can point to specific mechanical or hydraulic issues within the skid steer.
Common Causes of Jerky or Bucking Movement
There are several possible reasons for jerky or bucking behavior in a Bobcat 1835B skid steer. The most common causes include issues with the drive system, hydraulic system, or even operator errors. Let’s take a closer look at these potential causes.
1. Hydraulic System Malfunction
The hydraulic system plays a crucial role in controlling the movement of the skid steer, particularly in its drive motors and bucket operations. If there is a malfunction or restriction within the hydraulic system, it can lead to jerky movements.

• Low Hydraulic Fluid: Insufficient hydraulic fluid can cause inconsistent pressure, leading to jerky movements when operating the drive motors or other hydraulic-powered components.
  
• Air in the Hydraulic Lines: Air bubbles trapped in the hydraulic fluid can cause pressure surges, resulting in uneven movements. This can occur due to improper maintenance or leaks in the hydraulic system.
  
• Faulty Hydraulic Pump or Valves: A failing hydraulic pump or malfunctioning valves can cause irregular fluid flow, affecting the machine's ability to move smoothly.
  

Solution: Check hydraulic fluid levels regularly, replace damaged hydraulic lines, and ensure that there are no air bubbles in the system. If issues persist, inspect the hydraulic pump and valves for wear or damage.
2. Drive Motor Problems
The drive motors in a Bobcat 1835B skid steer are responsible for propelling the machine. If these motors experience wear or malfunction, it can result in jerky, uneven movements. The issue might stem from:

• Worn Drive Belts: The drive belt may slip or wear down over time, causing inconsistent power delivery to the drive motors. This could lead to a sudden lurching of the skid steer.
  
• Drive Motor Failure: If one of the drive motors is not functioning properly or is partially seized, it could cause one side of the skid steer to move erratically, resulting in bucking motions.
  

Solution: Regularly inspect and replace drive belts as part of routine maintenance. If a drive motor is found to be defective, it should be repaired or replaced immediately.
3. Hydraulic Coupler or Fitting Issues
In some cases, the couplings and fittings that connect hydraulic hoses and valves can become loose or damaged. These issues may not only lead to leaks but also cause inconsistent pressure or interruptions in the flow of hydraulic fluid. This can result in jerky or bucking behavior.
Solution: Tighten any loose couplings or fittings. Look for visible leaks in hydraulic lines, especially around the couplers, and replace damaged parts as needed.
4. Malfunctioning Joystick Controls
The joystick controls in a Bobcat 1835B skid steer are responsible for directing the machine’s movement. If these controls become worn or miscalibrated, they may send incorrect signals to the hydraulic system, causing the machine to jerk or buck unexpectedly.

• Worn Joystick Components: Over time, the internal components of the joystick can wear down, resulting in inconsistent signals or delayed responses.
  
• Electrical or Wiring Issues: Electrical issues, such as faulty sensors or wiring, can disrupt the communication between the joystick controls and the hydraulic system.
  

Solution: Check the joystick controls for wear or irregular operation. Recalibrate or replace faulty components as necessary. Inspect the wiring and connections for any signs of corrosion or loose connections.
5. Improper Operator Techniques
While mechanical and hydraulic issues are often the root cause of jerky movements, operator technique can also play a role. Improper use of the throttle, sudden or aggressive movements with the joystick, or jerky acceleration can contribute to uneven motion.
Solution: Train operators on smooth operation techniques. Encourage gradual acceleration and deceleration rather than sudden bursts of speed. Practicing smooth, controlled movements will reduce the likelihood of jerky or bucking behavior.
6. Poor Ground Conditions
Uneven or unstable ground conditions can also contribute to jerky movements in skid steers. If the machine is operating on a rough surface or encountering obstacles, it may struggle to maintain smooth movement, leading to jerking or bucking.
Solution: Assess the terrain before operation and avoid areas with excessive debris, holes, or loose gravel. Using the proper attachments, such as a grading bucket, can help smooth out the ground before proceeding with tasks.
Preventive Maintenance and Troubleshooting Tips
To prevent jerky or bucking behavior, regular maintenance and careful operation are essential. Below are some tips to keep your Bobcat 1835B skid steer running smoothly:

• Check Hydraulic Fluid: Ensure that the hydraulic fluid is clean and at the proper level. Replace it regularly and always use the recommended fluid type.
  
• Inspect Drive Motors: Regularly inspect drive motors, belts, and associated components for signs of wear or damage.
  
• Calibrate Joysticks: Regularly calibrate joystick controls to ensure that they are properly aligned and functioning.
  
• Perform Routine Inspections: Conduct a thorough inspection of the hydraulic system, drive motors, and electrical components to identify any potential issues early on.
  
• Use the Machine Properly: Train operators to handle the skid steer with care, using smooth acceleration and deceleration to avoid jerky movements.
  

Conclusion
Jerky or bucking behavior in the Bobcat 1835B skid steer can be caused by a range of factors, from hydraulic system issues to mechanical faults or operator errors. Regular maintenance, careful inspections, and proper handling techniques can significantly reduce the likelihood of encountering these issues. By addressing potential problems early and keeping the machine well-maintained, operators can enjoy smooth, efficient performance from their skid steer, improving both safety and productivity on the job site.