Well, how do I top that? My previous blog about the Harley-Davidson Twin-Cam chain tensioners was the most read blog in J&P Cycles’ blog history. We have been asked for permission to reprint or repost a number of times, and in general, I believe it accomplished exactly what I wanted it to. You can see we had numerous responses from riders sharing their personal experiences. This shows that education regarding how to handle and prevent this was needed. I’d like to thank our readers for taking the time to share with us exactly what they went through. Now, I’d like to address some of the responses.
The most prevalent question was “Does this affect my bike?” The cam chain tensioners are in every Twin-Cam engine produced (from the factory) from 1999 through today. Potentially, this affects every Big Twin engine made during this time. There was an update to Hydraulic Tensioners in 2007 that lessens the impact and greatly delays the possible failure point, but they still must be periodically checked. The wear out point is much later, but it does come. You Sporty riders are not affected as your cams are gear driven. You guys with Evo engines are also off the hook as your engines are also gear driven. (Hmmmmm, see a pattern here?)
One thing I did not address previously is crankshaft run out and the relationship to how it can create issues with a gear drive. Yes, it can create a problem. You must look at this prior to jumping to gear drive. If it is too far out, your choices are limited; however, the chain tensioners have allowed Mother Harley to relax crankshaft tolerances. To me, it seems that this is a self-generated comedy of errors.
Gear drives served you well Mother Harley. After all, you used them from 1936-1999 in Big Twins and 1957-2013 in Sportsters. You know how to do it. Only now it seems like we have to convince (beg?) you to. Keep the crank run out inline, and go back to gears
Now, I would like to point out that gears can be noisier than a shoe arrangement like this. Mother Harley has to satisfy noise emission guidelines mandated by the Environmental Protection Agency, and using this type of arrangement MAY be part of their compliance. I’m not making excuses for them, but without their giving us a direct answer there may be more to it than dollars and cents. I’d love to hear from corporate Harley about this and I could almost guarantee that we would post that answer. How about it readers? Would you like to see a response from the Factory?