Various example embodiments relate to rotating coalescers. One embodiment includes a housing comprising a first housing section having a blowby gas inlet structured to receive crankcase blowby gases from a crankcase. The housing further comprises an oil outlet. The rotating coalescer includes an endcap and filter media. The filter media is arranged in a cylindrical shape and is coupled to and positioned between the first housing section and endcap. The filter media is structured to filter the crankcase blowby gases passing through the filter media by coalescing and separating oils and aerosols contained in the crankcase blowby gases. The rotating coalescer includes a hollow shaft extending through the housing and positioned radially inside of the filter media. The hollow shaft forms a blowby gas outlet structured to route filtered crankcase blowby gases out of the housing. The rotating coalescer further includes a drive mechanism operatively coupled to the hollow shaft.