An assembly includes a track having an axis. The assembly includes a vehicle seat moveable relative the track along the axis. The assembly includes a ramp elongated along the axis. The assembly includes a linear variable differential transformer having a housing and a plunger moveably supported by the housing. The plunger contacts the ramp. The ramp being fixed relative to one of the vehicle seat or the track and the housing of the linear variable differential transformer being fixed relative to the other of the vehicle seat or the track.