Steering Wheel Lock Plate Remover/Installer Zing plated steel is 9/16 18 threads, Black plated steel is 14mm threads. Simplifies removal and installation of the round, Wire snaprings relaining steering wheel lock. This tool is a must for access to turn signal switches on current models of GM Cars. For all late odel GM, AMC, and Chrysler model cars with either tilt or conventionl steering columns.