Did you ever figure out what plug they replaced with the steering shaft? I'm starting to wonder if it does have something to do with it. Mine was making some loud high pitched noises yesterday in park just moving the steering wheel back in forth and sometimes when I turn to go around a corner the rattle will go away until I hit a bump in the road then it comes back. It gets extra loud on interstate after hitting a good sized bump until I stop and turn. Just curious what yours did and if it had any of those characteristics?