Troubleshooting Case: Komatsu PC200-6 Swing Bearing Failure

Problem Description:

A Komatsu PC200-6 excavator was experiencing unusual noise and jerky movement during swing operations. The machine had accumulated approximately 8,500 service hours with visible wear on the swing mechanism.

Diagnosis:

Technicians identified excessive play in the swing circle and metal particles in the gear oil. The slewing bearing (Part Number: 20y-25-21200) showed significant wear on the raceways and gear teeth damage with visible pitting and spalling.

Solution:

Replaced the damaged slewing bearing with a genuine-quality replacement part from Growshine International. The comprehensive repair included:

• Complete disassembly of upper structure and removal of old bearing

• Thorough cleaning of mounting surfaces and inspection of gear teeth

• Proper alignment during installation using precision instruments

• Correct torque application on mounting bolts following manufacturer specifications

• Fresh gear oil replacement and system pressure testing

• Final operational testing and quality verification

Result:

The excavator returned to smooth operation with no abnormal noises or vibrations. The replacement part performed optimally with proper load distribution and smooth rotation, extending the equipment's service life.

Preventive Maintenance Tips:

• Regular inspection of gear teeth for wear and proper lubrication

• Monitor for unusual noises during swing operation and address immediately

• Check for proper lubrication levels and contamination regularly

• Inspect mounting bolt torque periodically and retighten as needed

• Schedule regular maintenance according to manufacturer recommendations