Case 850H Transmission Parts

[MikePhua]

Overview of the Case 850H Crawler Dozer
The Case 850H is a powerful and versatile crawler dozer, part of Case Construction Equipment's lineup of heavy-duty machinery. It is widely used in construction, grading, and earthmoving tasks. Known for its excellent maneuverability, robust performance, and durability, the 850H features a hydrostatic drive system and a 6.7L engine, which provides the necessary torque for tough tasks like heavy pushing, rough grading, and trenching.
One of the critical components of the 850H, like any crawler dozer, is the transmission. The transmission system is essential in transferring power from the engine to the tracks, enabling the machine to move and perform its tasks efficiently. However, issues with transmission parts, such as wear and tear or component failure, can significantly impact performance, leading to costly downtime and repairs.
Key Transmission Components in the Case 850H
The transmission system of the Case 850H crawler dozer consists of several important components that work in unison to ensure smooth operation. These include:

1. Transmission Pump: The pump is responsible for circulating hydraulic fluid throughout the transmission, providing the pressure necessary to operate the transmission system.
   
2. Torque Converter: This device connects the engine to the transmission and helps smooth out power delivery, allowing for a more gradual acceleration and deceleration.
   
3. Hydrostatic Drive Motor: In the 850H, the hydrostatic drive system uses a motor that is powered by hydraulic fluid to drive the tracks. This system offers a smoother and more controlled movement compared to traditional mechanical transmissions.
   
4. Clutch Packs: These are critical for engaging and disengaging the gears within the transmission. Worn or damaged clutch packs can lead to slipping, poor acceleration, or difficulty in changing speeds.
   
5. Transmission Control Valve: The valve regulates the flow of hydraulic fluid within the transmission, controlling the shift points and ensuring proper operation under different load conditions.
   
6. Cooling System: The cooling system helps maintain the proper temperature of the transmission and its components. An overheated transmission can suffer from premature wear or failure.
   

Common Issues with the Case 850H Transmission
Despite its durability, the transmission system in the Case 850H can experience issues, especially with high-use machinery. Some of the most common transmission-related problems include:

1. Transmission Fluid Leaks: Over time, seals and gaskets within the transmission system can wear out, causing fluid to leak. Low fluid levels can lead to overheating, poor performance, and eventual transmission failure if not addressed promptly.
   
2. Clutch Pack Wear: Clutch packs are prone to wear, especially when they are engaged and disengaged frequently. This wear can lead to slipping, poor shifting, or even complete failure to shift into gear.
   
3. Hydraulic Pump Failure: The hydraulic pump is essential for powering the transmission, and if it fails, the machine will lose its ability to move effectively. This issue is often caused by poor maintenance or contamination in the hydraulic system.
   
4. Torque Converter Issues: A malfunctioning torque converter can cause the engine to rev without transferring power to the tracks, resulting in a loss of power and drive capability.
   
5. Overheating: If the transmission cooling system fails or the fluid is low, the transmission can overheat. Overheating can lead to severe damage to internal components, including the clutch packs and seals.
   

Maintaining the Transmission System
Proper maintenance is essential to keep the transmission system of the Case 850H operating smoothly and to avoid costly repairs. Here are some important steps to maintain the transmission:

1. Regular Fluid Checks: Always check the transmission fluid levels regularly and top up when necessary. Low fluid can lead to overheating and increased wear on internal components. Use only the recommended fluid type for the 850H to ensure optimal performance.
   
2. Inspect for Leaks: Periodically inspect the transmission system for any signs of fluid leaks. Pay particular attention to seals, gaskets, and hose connections. Address any leaks immediately to prevent fluid loss and contamination.
   
3. Change the Fluid and Filters: Over time, transmission fluid can become contaminated with particles that can cause damage to internal components. Changing the fluid and filters at the recommended intervals will help prevent this. Always use high-quality fluid and filters as specified in the operator’s manual.
   
4. Monitor the Cooling System: The cooling system is vital for preventing overheating of the transmission. Ensure that the radiator and cooling lines are free of blockages and that the fluid is at the proper level.
   
5. Check Clutch Packs and Drive Components: If you notice any hesitation when shifting or difficulty in maintaining power, it could indicate wear on the clutch packs or drive components. Have these parts inspected and replaced as needed.
   
6. Regularly Service the Hydraulic System: Since the Case 850H uses a hydrostatic transmission, maintaining the hydraulic system is critical. Regularly change the hydraulic oil and replace the filters to ensure smooth operation of the hydraulic motor.
   

Troubleshooting Transmission Problems
If you experience transmission issues with your Case 850H, follow these steps to troubleshoot:

1. Check Fluid Levels: If the machine is experiencing poor movement or shifting issues, the first step is to check the transmission fluid level. Low fluid levels can cause sluggish movement, overheating, or slipping.
   
2. Inspect for Leaks: Look for any visible fluid leaks around the transmission system. Leaking seals, gaskets, or hoses can lead to a loss of fluid and poor performance.
   
3. Test the Hydraulic Pump: If the pump is malfunctioning, you may notice that the machine has trouble moving or lacks power. Check for any unusual noises, vibrations, or a loss of hydraulic pressure, which could indicate a failing pump.
   
4. Examine the Torque Converter: If the engine runs but the machine doesn’t move, the issue may be with the torque converter. Testing the converter may require disassembling parts of the machine, so it’s often best left to a professional.
   
5. Check the Clutch Packs: If shifting is rough or there is slippage when accelerating, the clutch packs may be worn. If needed, the clutch packs should be serviced or replaced.
   

Conclusion
The transmission system in the Case 850H is a critical component that ensures the dozer can perform its earthmoving tasks efficiently. Regular maintenance, such as checking fluid levels, inspecting for leaks, and servicing the hydraulic system, can help prevent costly transmission repairs. If you experience issues with the transmission, it’s essential to diagnose the problem early and address it to prevent further damage. With proper care and attention, the transmission system in the Case 850H can continue to operate smoothly, extending the life of your machine and improving overall productivity on the job site.