A method of maintaining a gas-turbine engine is provided. The method includes the steps of removing a conduit from the gas-turbine engine, installing a temporary oil filter in place of the conduit in the gas-turbine engine, and starting the gas-turbine engine with the temporary oil filter installed. A fan-drive gear system is also provided and comprises a journal bearing, a main oil pump fluidly coupled to the journal bearing, a main oil filter fluidly coupled between the journal bearing and the main oil pump, and an auxiliary oil pump fluidly coupled to the journal bearing. The auxiliary oil pump may be configured to supply oil to the journal bearing on startup. An auxiliary oil filter may also be installed between the auxiliary oil pump and the journal bearing.