In light of the tensioner failures in Hemi engines, I decided to check the tensioner differences in the newer and engines. Here's what I've found.
All Hemi engines (6.1L included) installed through 2008 have the older leaf spring style tensioner which is NOT prone to this failure, so you guys and gals can relax.
In 2009, with the introduction of the Eagle engine, the new style coil spring tensioner was also introduced into the 5.7 Hemi in all applications. In 2011, a running change was made to the tensioner (from PN 53022115AG to PN 53022115AH) so this year could have either part number installed. 2012 and up has the latest revision installed. This information also applies to the 6.4 Hemi.
- The following paragraph is not information from Chrysler. It is my own opinion based on information I have gathered from various sources.
From what I am seeing, I believe the AG part number is the one causing the problem. This would explain the running change in 2011 as well as the mileages of known failures. That means that the 2009-2010 models as well as some 2011 could be affected.
For those of you that are curious, here are images of the coil spring and leaf spring styles. Both coil spring part numbers appear to be the same in all images I have seen thus far.
Coil Spring Style
The timing chain tensioner is a spring loaded design. It consists of two chain guide shoes. One shoe is fixed in place and the other is spring loaded to keep tension on the chain.
Leaf Spring Style
The timing chain tension is maintained by routing the timing chain through the tensioner assembly. A nylon covered spring steel arm presses on the timing chain maintaining the correct chain tension.