I have a stock 07 lsj with 155 000 kilometers.
How do the timing chain fixed, adjustable and upper guides hold up. I realize there is no maintenance interval but its plastic so do i need to worry about it. I am not having any drivability problems or cam crank correlation dtc.

 

Always replace them. The entire kit is cheap enough that it's not worth trying to skip them. If they do go, and it's common enough, motor go boom.

 

i'm trying to determine an interval for replacement: I have no data on when they have failed for others.

 

Although you could stretch longer, general consensus is every 100,000mi. Some have failed before and some never, a lot of variables to account for.

 

Depends on a thousand factors. I've always generally seen 100,000 miles (~160,000 km) as a general recommendation.

My timing chain tensioner started to fail around 70,000 miles, iirc.

 

Replacing mine next week. 185,000km, or roughly 115,000 miles. There's definitely signs of slack that I hear.