Well, if it's what we've been seeing for a while on the LXs with the 5.7L, then it's the eagle engines with a few older ones thrown in for good measure. The timing chain tensioner spring fails causing the timing chain to hit the slider which will basically break the slider into several pieces and sometimes crack the thrust plate. It has happened on a few stock vehicles, but typically it's seen with mildly modified engines. The basic fix is to swap in a 6.1L thrust plate and there will be no issues. You can tell the difference between the 6.1L thrust plate because it's black and the 5.7L one is silver/grey. Just the fix that the LX guys have been doing for the past few years.