Fault Phenomenon: CAT rotary drilling rig a harsh metallic grinding sound comes from the track while driving, the idler does not turn or wobbles.

Troubleshooting Process:
– Checked idler: internal bearing completely shattered.
– Checked seal: floating oil seal failed, water and mud ingress.
– Checked lubrication: gear oil lost.
– Checked tension: excessive track tension.

Root Cause: The idler floating oil seal failed, allowing mud and water to enter the wheel body, causing bearing lubrication failure and rapid wear, leading to cage collapse.

Required Parts: Replace idler assembly and adjust track tension.