Fault Phenomenon: Volvo EC360 excavator a loud rumbling sound occurs during swing, eventually stops.

Troubleshooting Process:
– Checked gearbox: planetary gears broken or pitted.
– Checked bearings: bearing cage collapsed.
– Checked lubrication: insufficient or deteriorated gear oil.
– Checked foreign objects: metal debris jamming gears.

Root Cause: The swing gearbox planetary gear broke due to fatigue or poor lubrication, seizing the entire swing mechanism.

Required Parts: Replace swing gearbox assembly or gear set.