Fault Phenomenon: Caterpillar 785 mining truck wheel hub gearbox gear oil appears milky white, gears wear quickly.

Troubleshooting Process:
– Checked oil seal: floating oil seal failed, mud and water ingress.
– Checked breather cap: breather clogged, condensation accumulation.
– Checked oil change: long-term no change.
– Checked housing: housing cracked, water ingress.

Root Cause: The wheel hub gearbox floating oil seal failed, allowing external mud and water to enter the gearbox, causing gear oil emulsification.

Required Parts: Replace floating oil seal, replace gear oil.