Hyundai HL940A Front Axle Noise When Turning

Confirmed cause: The planetary carrier had a fracture originating from one of the planetary gear pin bores. This allowed the pin to walk out, causing the planetary gear to misalign and break apart, destroying the carrier and the ring gear. Repair performed: Drained the oil and removed the left front wheel and planetary hub cover. Removed the damaged planetary carrier, gears, and bearings. Cleaned the hub and ring gear surfaces and inspected for further damage. The sun gear and axle shaft were undamaged. Installed a new planetary carrier assembly, including new gears, pins, and bearings. Installed a new ring gear, which had been damaged by the failed components. Reassembled the hub with new seals and gaskets. Filled with new gear oil to the specified level. Verification: With the front axle still raised, the left wheel was rotated by hand through multiple full steering cycles. The wheel now rotated smoothly with no binding or abnormal noise. The machine was then lowered and road tested in a yard, performing multiple sharp turns in both directions. The popping noise was gone. Technician notes: - The metal contamination was confined to the planetary hub. This indicates the failure was recent and saved the differential from contamination. - Careful cleanup of the hub interior is critical to prevent residual debris from causing a repeat failure of the new components. - This failure is uncommon. It may have been initiated by a stress crack or a previous shock load event.