Is this about replacing the plastic timing chain tensioner with a metal one?
To clarify, LR did not use a "plastic" tensioner. There are two arched guides made from aluminum that are thrust against the timing chain via oil driven tensioners that have steel push rods or plungers. There are 2 issues at hand:
1: First and worst, we have a steel rod pushing against an aluminum lever at a very low fulcrum. Lots of pressure and movement, and it's only a matter of time till the steel begins to dig into the aluminum. Boggles the mind someone didn't stop this obvious flaw.
2: The angle of attack for this steel push rod was also poorly thought out, not hitting the guide at a true 90 degrees. This allows the rod to dig into the aluminum even more aggressively. See #1.
LR's solution: Sometime in the run up to 2013MY, they revised both the guide and tensioner. The new guide now has a steel bearing plate where the tensioner contacts, providing much more wear resistance. Next, the tensioner has been redesigned to change its AOA to a more square on position. The mounting holes stayed the same, and these revised parts are the ones you will receive from the LR parts counter.
My son has a Ford Mustang 4.0L V6 from the FORD/Jaguar era, which recently grenaded its entire timing chain system. Something tells me Ford engineers didn't have a clue how to design timing chain systems, or the accounting folks stuck their nose in too far.
Here's an excellent video:
https://youtu.be/yFXt2IBgRKc
