Gearbox deoiler with pre-pressuring component

A gearbox (12) includes an inlet (52) configured to receive a mixture of air and oil from an external source and a deoiler (40). The deoiler includes a shaft (41) including an inlet passage (97) and an outlet passage (42), both formed on an inner portion of the shaft and separated from one another, a separator unit (58) coupled to and surrounding a portion of the shaft and including an inlet (56) and an outlet, and a pre-pressuring component (90) coupled to the shaft that increases the pressure of the mixture of oil and air to form a pressurized mixture and provides the pressurized mixture to the inlet (56) of the separator unit.