Bobcat 337 Travel Motor Bearing Issues and Solutions

[MikePhua]

The Bobcat 337 is a versatile and powerful mini-excavator designed to handle a wide range of construction and landscaping tasks. However, like all machines, it is subject to wear and tear, and one common issue that many operators face is the travel motor bearing problem. The travel motor is crucial for the mobility of the Bobcat 337, and any issue with it can significantly affect the machine's performance. This article explores the causes, symptoms, and solutions for travel motor bearing issues in the Bobcat 337.
Overview of the Bobcat 337 Mini Excavator
The Bobcat 337 mini-excavator is part of the popular Bobcat range of compact construction equipment, designed for precision and efficiency. With a powerful engine and advanced hydraulics, the 337 is ideal for tight job sites where larger machines can’t maneuver. Key features include:

• Operating Weight: Approximately 8,500 lbs (3,856 kg)
  
• Engine Power: 35.6 hp (26.5 kW)
  
• Digging Depth: 10 feet 2 inches (3.1 meters)
  
• Hydraulic Flow: 17.4 gpm (66 liters per minute)
  

Its compact design, powerful hydraulics, and durability make the Bobcat 337 suitable for digging, lifting, and trenching tasks, especially in areas with limited access.
What is the Travel Motor and Its Role?
The travel motor in a mini-excavator like the Bobcat 337 is responsible for the movement of the machine, allowing it to travel forward, backward, and rotate. It’s an integral part of the undercarriage and consists of a hydraulic motor that powers the tracks. The travel motor is composed of several components, including the bearings, gears, and hydraulic seals. These components work together to transmit power from the engine to the tracks, enabling the machine to move efficiently.
Symptoms of a Failing Travel Motor Bearing
Over time, the travel motor bearings may experience wear and tear, leading to a variety of issues. Some of the common signs that your Bobcat 337 might be experiencing travel motor bearing problems include:
1. Grinding or Humming Noises
If you hear unusual grinding or humming sounds while operating the Bobcat 337, especially when moving, it could be an indication that the travel motor bearings are starting to fail. These noises are often caused by excessive wear on the bearings, which may lead to them grinding against other components.
2. Reduced Travel Speed or Jerky Movement
A failing travel motor bearing can cause the excavator to move erratically. If you notice that the Bobcat 337 is not moving smoothly or is moving at a reduced speed, it may be due to friction caused by damaged or worn bearings.
3. Leaking Hydraulic Fluid
When travel motor bearings wear down, they may cause hydraulic seals to fail. This can lead to hydraulic fluid leaks, which not only affect the performance of the travel motor but also risk damaging other components of the excavator’s hydraulic system.
4. Excessive Heat
Worn bearings can generate excess heat due to the increased friction in the travel motor. If you notice that the travel motor is running hotter than usual, it might be a sign of bearing failure. Prolonged heat buildup can cause further damage to the motor and hydraulic components.
Common Causes of Travel Motor Bearing Failure
Several factors can contribute to travel motor bearing failure in the Bobcat 337. These include:
1. Lack of Proper Lubrication
The travel motor bearings rely on proper lubrication to function smoothly. If the bearings are not adequately lubricated, it can lead to increased friction and wear. Lack of lubrication can be due to infrequent maintenance, improper oil levels, or using the wrong type of lubricant.
2. Contaminated Hydraulic Fluid
Contaminants in the hydraulic fluid, such as dirt, metal particles, or water, can accelerate wear on the bearings and other components of the travel motor. Contaminants can enter the hydraulic system through worn seals, damaged hoses, or poor maintenance practices.
3. Excessive Load and Overuse
Excessive loads and prolonged use in harsh conditions can put additional strain on the travel motor. Continuous heavy lifting, working on uneven terrain, or using the excavator beyond its rated capacity can cause the bearings to wear out faster.
4. Improper Installation or Alignment
When the travel motor is improperly installed or misaligned, it can cause uneven pressure on the bearings, leading to premature failure. Regular inspections during maintenance can help detect alignment issues before they cause significant damage.
Steps to Fix Travel Motor Bearing Issues
If your Bobcat 337 is experiencing travel motor bearing issues, it’s crucial to address the problem as soon as possible to prevent further damage. Here are the general steps for fixing travel motor bearing problems:
1. Inspection and Diagnosis
Before taking any action, perform a thorough inspection of the travel motor and surrounding components. Look for signs of wear, leakage, or misalignment. You may also need to consult the machine's service manual for specific guidance on diagnosing travel motor bearing issues.
2. Drain Hydraulic Fluid and Remove the Motor
To replace or repair the travel motor bearings, you’ll first need to drain the hydraulic fluid from the system. After draining, remove the travel motor from the machine by disconnecting the hydraulic hoses and bolts that secure it to the undercarriage.
3. Disassemble the Travel Motor
Once the travel motor is removed, disassemble it to access the bearings. Carefully inspect each component for wear and damage. Pay particular attention to the bearings, seals, and gears. If any components are damaged, they will need to be replaced.
4. Replace the Bearings
Remove the worn bearings and replace them with new, high-quality bearings that meet the manufacturer’s specifications. Use a bearing press to ensure proper installation and avoid causing damage to other components during the process.
5. Reassemble and Test
After replacing the bearings, reassemble the travel motor and ensure that all components are correctly aligned. Reconnect the hydraulic hoses and refill the system with the appropriate hydraulic fluid. Test the machine to ensure that it moves smoothly and that there are no unusual noises or leaks.
Preventing Future Travel Motor Bearing Problems
To prevent travel motor bearing issues in the future, follow these maintenance practices:
1. Regular Lubrication and Fluid Checks
Ensure that the travel motor bearings are properly lubricated by performing regular lubrication checks. Additionally, monitor the hydraulic fluid levels and ensure that the fluid is clean and free of contaminants.
2. Use High-Quality Hydraulic Fluid
Use only high-quality hydraulic fluid recommended by the manufacturer. Contaminants in the fluid can accelerate wear and cause damage to the travel motor bearings.
3. Follow Manufacturer’s Guidelines for Load Limits
Avoid overloading the Bobcat 337 or using it beyond its rated capacity. Operating the machine within its specifications will help prevent unnecessary strain on the travel motor and its bearings.
4. Regular Inspections
Regular inspections of the travel motor, bearings, and surrounding components can help identify potential problems before they lead to major failures. Look for signs of leaks, unusual noises, or wear during routine maintenance.
Conclusion
The Bobcat 337 is a robust and efficient mini-excavator that can tackle a wide variety of tasks. However, like any machine, it is susceptible to issues like travel motor bearing failure. By understanding the symptoms, causes, and solutions for these problems, operators can keep their machines running smoothly and avoid costly repairs. Regular maintenance, proper lubrication, and timely repairs will extend the life of the travel motor and ensure that the Bobcat 337 continues to perform at its best.