Not sure if this has been posted yet, but it is a really good article on the history of the Twin Cam 88.


https://www.cycleworld.com/harley-da...story-big-twin


Of particular interest, and the reason I stumbled upon this article, is this section:


"2003 Twin Cam 103. Plain roller on drive side takes the place of previously used pair of Timken tapered rollers. This has since led to big discussion among Harley mechanics and builders. The paired Timkens strongly resisted shaft wobble in a way the newer single roller cannot. For high duty operation, custom builders often prefer the Timkens. The Timkens required a time-consuming installation of pressing onto the sprocket shaft, whereas the single roller is installed in the case and the crank is then slid into it, saving assembly time."


This clears up the question, at least for me, on when Harley stopped using paired Timkens on the crank shaft.


Hope this helps someone else too!

 

Good read.

1999-2006 Rapid wear of plastic facing on cam tensioner blades—said to fail as early as 15,000-miles. These were originally stiffly spring-tensioned but that system has been replaced 2007-onward by hydraulic tensioning. The hydraulic tensioning system delays the failure but does not prevent it—it now occurs at 50,000-75,000 miles.

I was surprised to see how much wear I had on my rear tensioner at 65,000. Front still looked like new. I wonder why Harley doesn't have some type of recommended cam chest maintenance at 75K. Glad I changed my bearings, lifters and tensioners at 65K.