Fault Phenomenon: Bauer BG30 rotary drilling rig excessive play and abnormal noise at the connection between mast and chassis.

Troubleshooting Process:
– Checked pins: connection pins worn thinner.
– Checked bushings: bushings severely worn or cracked.
– Checked lubrication: grease fittings clogged, lack of lubrication.
– Checked structure: lug holes worn and deformed.

Root Cause: The mast foot connection pins and bushings were dry-worn due to long-term lack of lubrication, causing excessive clearance.

Required Parts: Replace pins and bushing assemblies, repair lug holes.