Fault Phenomenon: Volvo G970 grader abnormal noise during blade swing, inspection reveals loose ring gear mounting bolts.

Troubleshooting Process:
– Checked bolts: high-strength bolts fatigued and loose.
– Checked washers: washers failed or missing.
– Checked torque: not tightened to specified torque.
– Checked threads: threads damaged.

Root Cause: The blade swing ring gear mounting bolts were not tightened to the specified torque and sequence, causing loosening due to vibration.

Required Parts: High-strength bolts and washers, retighten.