Here is a better picture of the offending part in LS3 (and LS7 I beleive). Same as Audi, and pretty much every other manufacturer, they used some sort of nylon, which sometimes brakes at engine temperature.
Its a real shame because there are better materials out there such as Stanyl Diablo (recently selected by Fiat) and Duratron CU60.
And here is the thread advising replacement with the LS1 chain dampner. Shame because the LS3 tensioner looks like a better design because its keeping tension on the chain not just preventing vibration and jumping.
http://ls1tech.com/forums/generation...work-pics.html
If I ever have the money to get a LS3 this is the first part I would change before the engine went in the car.