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Hard to argue there! If they were already using a heavier built chain and it was still breaking, then it stands to reason there is something funky going on with the tensioners or vvt or mds. However, when the chain itself is not looking that substantial, that really begs to reason to being the culprit first and foremost.
Another detail to this is that even if the existing chain is quite fine for durability, it still a more narrow chain as far as contacting the tensioner shoe. A thinner chain will then have a more concentrated force where it contacts the shoe, sort of like grinding it down like a buzz saw until the shoe fails. A more substantial chain (wider, more layers) would better distribute that contact force on an equally wider tensioner shoe, facilitating less wear for a given tensioning force. Does that sound plausible? Maybe a wider chain has more strength than is needed, but there is just no escaping that it may be the wear on the tensioner shoe (on a narrow chain) that is the real bottleneck on this? When the shoe snaps, it takes out everything with it...
Aside from the obvious factor of mds functionality, the cam is a bit different between the 6-spd and auto versions of the 5.7 Hemi, right? Maybe there is a different tensioner stiffness value that is spec'd in conjunction with respective cam? If they saw fit to run a stiffer setting on the mds cam, that could be another explanation for excessive wear seemingly unique to the mds Hemi.
Last edited by randycat99; 06-27-2012 at 11:26 AM.