A variable-vane cartridge mechanism for a turbocharger is assembled from a nozzle ring, an insert that engages a turbine housing bore, and a plurality of spacers. Holes larger in diameter than the spacers are formed in the nozzle ring and a nozzle portion of the insert, such that the spacers fit loosely in the holes. A locating fixture is engaged with the nozzle ring and insert for precisely locating these parts radially (and optionally also axially) with respect to each other; the spacers can move within the holes as needed to allow the positions of the parts to be adjusted. Once located relative to each other, the nozzle ring and insert are fixed in the desired relative positions by affixing the spacers to them, such as by welding.