When was the latest part put out? I missed hearing anything on this one. Thx.
JW
There have been three versions, the original plus two revisions.
40063-05 - June 2005
40063-05A - November 2006
40063-05B - January 2010
The changes had more to do with the strength and durability of the actual tensioner (some early parts distorted and jammed), and the failure to engage the ratchet teeth properly that resulted in loose chains slapping the primary cover. While the -B- revision seems to have "fixed" actual physical failures and jamming of the mechanism, I don't see anything in the changes so far that addresses the too tight problem.
If you think back to the old manual system on the previous design primary, the chain became tighter as the parts heated up. The adjustment specs were 5/8-7/8" COLD, and 3/8-5/8" HOT. In other words, the chain slack was reduced by 1/4" as the parts came up to full operating temperature. I don't see anything in the current design "auto" tensioner that allows for that tightening of the chain as the parts heat up. So while the actual tensioners themselves may no longer fail with the latest revision level, the issue of overtightening doesn't appear to have been addressed. All that extra stress on the chain and other components wasn't unknown to Harley, they had issues before they sold the first Dyna with the new system in 2006. They originally planned to require a mandatory change of the IPB at 15k miles, and had early purchasers sign a form acknowledging that requirement, but halfway through the model year they dropped the requirement when the initial failure rate wasn't quite as bad as they feared. Of course we have been hearing about plenty of IPB failures ever since, but Harley has obviously determined that it's cheaper to fix the ones that fail within the warranty period than it is to address the design issues that are the root of the problem. After all, the average Harley probably doesn't go 2000 miles in a year, so all the MoCo has to worry about is the people who actually rack up some major miles.
JMHO of course - Jerry