This document discusses, among other things, a lead body extending longitudinally along a lead axis, a driver axially displaceable relative to the lead body, and a driven member coupled to the lead body and displaceable away from the lead axis. The driven member at least partially defines an expandable passage having at least one internal dimension. The driver is displaceable into the expandable passage and has at least one outer dimension that is larger than the at least one internal dimension of the expandable passage. An example method includes disposing a first member having a first cross-section in a lead assembly having a lead axis, an expandable passage, and a displaceable member proximate the expandable passage. The method further includes urging the first member into the expandable passage in the lead assembly, and urging the displaceable member away from the lead axis to expand the expandable passage.