Case 850 Transmission Issues: Diagnosis and Solutions

[MikePhua]

The Case 850 is a versatile and powerful track loader, known for its performance in demanding construction and agricultural environments. However, like any heavy machinery, it can experience transmission issues over time. These issues can lead to reduced efficiency, increased downtime, and costly repairs. Understanding common transmission problems, how to diagnose them, and the potential solutions is crucial for any operator or technician working with the Case 850.
The Case 850: A Brief Overview
The Case 850 track loader is widely recognized for its durability and ability to handle tough worksite conditions. Manufactured by Case Construction Equipment, the 850 model is used in applications such as grading, digging, lifting, and hauling materials. The machine is powered by a reliable engine and equipped with a robust transmission system that supports its wide range of tasks.
The transmission system in the Case 850 is designed to transfer power from the engine to the tracks, allowing for the movement and operation of the loader. This system is essential for the smooth operation of the equipment and its ability to navigate various terrains. Over time, however, mechanical wear, fluid issues, or environmental factors can cause the transmission to fail.
Common Transmission Issues in the Case 850
Several common transmission issues may arise in the Case 850, affecting the loader's ability to perform optimally. These include problems related to fluid levels, mechanical components, or electrical connections that control the transmission.
1. Slipping Transmission
One of the most common issues reported with the Case 850 is a slipping transmission. This occurs when the transmission fails to engage properly, resulting in the machine losing power while under load or failing to move at the correct speed. A slipping transmission can be caused by several factors, including low fluid levels, worn-out components, or a damaged torque converter.
Potential Causes:

• Low Transmission Fluid: Inadequate fluid levels can cause improper lubrication, leading to overheating and slipping gears.
  
• Worn-out Clutch Plates: The clutch plates are responsible for engaging and disengaging the gears. If they are worn or damaged, the transmission may slip.
  
• Torque Converter Issues: The torque converter regulates the flow of power from the engine to the transmission. A malfunction here can lead to slipping or a loss of power.
  

Diagnosis and Solutions:

• Check Fluid Levels: Always begin by checking the transmission fluid levels. If the fluid is low, top it up with the recommended type and quantity of transmission fluid.
  
• Inspect Clutch Plates: If the fluid level is fine and slipping persists, inspect the clutch plates for wear or damage. Worn clutch plates may need to be replaced.
  
• Examine the Torque Converter: If the torque converter is malfunctioning, it may require rebuilding or replacement.
  

2. Harsh Shifting or Difficulty Changing Gears
Another issue that may arise in the Case 850 is difficulty when shifting gears, or the transmission may engage harshly. This can cause the machine to jerk or hesitate when transitioning between gears, which can be uncomfortable for the operator and potentially damaging to the transmission.
Potential Causes:

• Contaminated or Old Fluid: Transmission fluid that has become contaminated or degraded over time can affect the smooth shifting of gears.
  
• Faulty Shift Solenoids or Valves: The shift solenoids control the fluid flow to engage the gears. If these solenoids are faulty, the machine may have difficulty shifting smoothly.
  
• Worn-out Synchronizers: Synchronizers help synchronize the rotation of the gears during shifts. Over time, these parts can wear out and cause difficulty in gear engagement.
  

Diagnosis and Solutions:

• Flush the Transmission Fluid: Start by draining the old fluid and replacing it with fresh, clean fluid. This will remove contaminants and help improve shifting performance.
  
• Inspect Shift Solenoids: If fluid replacement doesn’t resolve the issue, check the shift solenoids for wear or malfunction.
  
• Replace Worn Synchronizers: If the synchronizers are the cause, they may need to be replaced to restore smooth shifting.
  

3. Overheating Transmission
Transmission overheating is another common issue in the Case 850. Overheating can cause severe damage to internal components, leading to costly repairs and significant downtime. High transmission temperatures are typically the result of insufficient cooling or overloading the machine.
Potential Causes:

• Low Fluid Levels: As mentioned earlier, low fluid levels can cause friction within the transmission, leading to overheating.
  
• Blocked or Dirty Transmission Cooler: A dirty or clogged cooler can restrict fluid flow and cause the transmission to overheat.
  
• Excessive Load: Overloading the machine beyond its rated capacity can put excessive strain on the transmission, causing it to overheat.
  

Diagnosis and Solutions:

• Check Fluid and Cooling System: Ensure the fluid is at the proper level and that the transmission cooler is clean and functioning correctly. If necessary, clean or replace the cooler.
  
• Monitor Operating Conditions: Always ensure the machine is not overloaded. Refer to the operator’s manual for weight capacity limits and adjust the load accordingly.
  

4. No Movement or Limited Movement
In some cases, the Case 850 may fail to move at all, or it may only move slowly or intermittently. This issue is often linked to a problem with the hydraulic system or transmission control system.
Potential Causes:

• Hydraulic Pump Failure: The hydraulic pump is responsible for supplying fluid to the transmission. If the pump is faulty, it can cause a lack of movement or limited movement.
  
• Transmission Control Valve Malfunction: The transmission control valve regulates the flow of hydraulic fluid to the transmission. A malfunctioning valve can result in no movement or slow response.
  

Diagnosis and Solutions:

• Inspect Hydraulic Pump: Check for any signs of wear or damage to the hydraulic pump. If the pump is malfunctioning, it may need to be repaired or replaced.
  
• Check Transmission Control Valve: Test the control valve for proper function. If the valve is stuck or damaged, replacing it may resolve the issue.
  

Preventative Maintenance for Case 850 Transmission
While transmission issues are inevitable over time, regular maintenance can significantly reduce the likelihood of major problems. By following a proper maintenance schedule, you can extend the life of the transmission and improve the overall reliability of your Case 850 loader.
Recommended Maintenance Steps:

• Regular Fluid Checks: Consistently monitor the transmission fluid levels and quality. Low or degraded fluid should be replaced immediately.
  
• Lubrication: Ensure that all moving components within the transmission are adequately lubricated to reduce friction and wear.
  
• Clean the Cooling System: Regularly inspect and clean the transmission cooler to prevent overheating.
  
• Monitor Operating Conditions: Avoid overloading the machine and ensure proper use to prevent excessive strain on the transmission.
  

Conclusion
Transmission problems in the Case 850 can be frustrating and costly if not addressed promptly. By understanding the common issues, performing routine maintenance, and diagnosing problems early, operators can extend the life of the transmission and keep their machine running smoothly. Whether you're dealing with slipping gears, harsh shifting, or overheating, identifying the cause and taking appropriate action can help you avoid major repairs and reduce downtime.