Warning Signs to Look For in Your Swing Bearing | ConEquip.com

Key Warning Signs

• Contaminated Grease: If your lubricant contains metal particles or grit, it’s a red flag for wear. You’ll feel this when you purge the bearing and check the grease. It is suggested that during your daily checks, you rub some of the purged grease between your thumb and forefinger. If you feel grit or metal chips, you may have a bearing problem.

• Grinding, Popping, or Clicking Noises: Unusual noises often mean insufficient lubrication, excessive wear, or even loose bolts. These sounds may precede more severe issues. Keep an ear out and listen during operation for these tell-tale sounds.

• Increased Play or Lateral Movement When raceways—the common name for the tracks within the bearing—wear, the bearing clearance increases. That manifests as slack in the digger arm, compromising precision and potentially accelerating wear, especially when the boom is extended under load.

• Rising Torque or Binding If swing torque increases or the bearing binds or has tight spots, it likely indicates non-uniform race wear. You may experience resistance or uneven movement and even detect the upper structure continuing past its intended stop, spotlighting uneven load distribution.

• Visible Damage During Operation In advanced wear stages, the bearing may literally “pop” or crack as it rotates—especially under load. This stage is critical; immediate attention or replacement is needed.

Other Common Failure Causes & Solutions

• Fatigue & Overloading Constant heavy or uneven loads can cause micro-cracks in the raceways, leading to fatigue failure. Proper load distribution and avoiding overloads are crucial.

• Improper Installation & Misalignment Non-flat mounting surfaces, incorrect bolt torque, or misaligned installation can accelerate bearing wear via uneven loading. Ensuring proper installation is therefore vital.

• Contamination & Corrosion Dirt, debris, or moisture in the lubricant or housing can degrade raceways over time. Regular cleaning, sealing, and proper storage help prevent corrosion-related failures.

• Gear Tooth Failure In slew rings with geared teeth, broken or damaged teeth can result from gear misalignment, increased clearance, or stress. Proper gear design, maintenance, and correct clearance settings help mitigate this risk.

Best Practices for Longevity

• Grease Regularly During your regular maintenance, use EP2 or equivalent high-pressure grease. Grease slow-moving bearings roughly every 100 operating hours (or more frequently if use is heavy), and always purge until old grease emerges.

• Inspect Bolts and Preload Loose or improperly torqued bolts can lead to misalignment and failure. Regularly check and re-torque as needed. Also monitor bolt creep from vibration or heat.

• Seal Inspection Ensure seals are intact to keep contaminants out. Damaged seals can doom a bearing regardless of lubrication.

• Avoid Repetitive Loading Patterns Constantly digging from the same angle concentrates wear in one area. Varying your approach reduces localized stress and extends bearing life.