If the sensor is not present, you should install the sensor retainer and the steering shaft seal. If the sensor is present, you should install the sensor assembly, the sensor locator, the boot seal, the steering shaft assembly, the tilt head assembly, and the steering shaft into the steering column jacket assembly, lubricate the pivot pins with GM P/N 12346293 (Canadian P/N 992723), install the 2 pivot pins onto the steering column support assembly, the tilt spring assembly, the turn signal switch housing and the steering column to the vehicle and enable the supplemental inflatable restraint system.