Fault Phenomenon: Terex tower crane severe oil seepage at the swing gearbox mating surface and input shaft.

Troubleshooting Process:
– Checked breather cap: breather clogged, high internal pressure.
– Checked seal gasket: gasket aged.
– Cleared breather cap, replaced seal gasket.

Root Cause: Clogged gearbox breather caused internal pressure to rise, forcing oil out through the sealing surfaces.

Required Parts: Breather cap, seal gasket.