Crank sprocket issue was fixed for the 1Z engine.
You will notice other issues before the timing gets thrown out of wack from a loose crank gear
There is no replacement interval. If you notice the Damper wobbling replace it.
If you keep an eye on it you won't have an issue.
Yeah, not so much. I have seen and repaired a number of the crank gears moving on the 1Z/AHU. They may have changed the engineering, but it is anything but a ”fix”.
And no, you won’t notice other items out of whack before the timing starts moving. It doesn’t take a lot of movement to throw the timing off enough for hard and smoky starts. Often times people will attribute it to injectors or some other issue. There is tons of documentation on here about it.
If the dampener is wobbling, then it’s due to a bad dampener and not the crank sprocket. The crank sprocket does not move around enough to notice or even determine without the timing tools. Every one I have diagnosed and corrected never showed other issues but the crank sprocket was hammered when inspected upon removal.
There is no “keeping an eye on it” since you can’t see it happening. There is only the symptoms to go by that may point to the issue. When diagnosing problems on a TDI I always start with the basics: timing, fuel, air. The first has always revealed any crank sprocket issues.