An assembly for a turbocharger includes a ball bearing cartridge, a center housing with a bore, a turbine end counterbore and a compressor end surface that includes a recess, and a compressor backplate with an axial extension configured to fit into the recess where the counterbore and the backplate define, at least in part, an axial length of a bearing cartridge chamber. Various other devices, assemblies, etc., are also disclosed.