Hello,

I have a Dyna 2006, and I worry about the crank. I have read at many places about the 2007 Harley crankshaft issues with too much runout. But what about the Dyna 2006 cranks? Anyone know?

Manual says runout must not exceed 0.003”. 2 years ago I measured 0.0021” at cam swap, but last year I increased bore and compression, so I am a bit concerned now.

I know that I have 4.000” stroke and that the 2007 models have 4.375” and so the cranks are different in that respect. But do they differ in quality?

I have read that Harley changed producer of the cranks around 2007. As Dyna 2006 was a pilot model, one may suspect that even the Dynas 2006 have that bad crank. But hopefully they were not affected as they still had the 4” stroke.

Does anyone know?

Answers are much appreciated.

Best Regards

 

You are over thinking. If you are concerned about runout after increasing bore and compression, pull the can chest and check. If runout has grown since bore and compression increased, you should probably keep an eye on it and check at the end of riding season. If runout is where it was befor increasing bore and compression, don't sweat it.

The sky was not falling in '07 after crank manufacture was outsourced off shore. There were some quality control issues but there weren't massive crank failures in the '07 model year, just a few more than normal. Relax.

 

Ok thanks, djl. I just wonder a lot about these cranks. Why do they fail like that? Not so good bearings any longer? Another producer off shore? Or maybe the introduction of the automatic primary chain tensioner holding the primary chain too stiff, not only destroying the inner primary bearing, but also contributing to crank shaft runout? (I changed to Hayden tensioner after inner primary bearing failure three years ago.)

 

Why to they fail? Short answer is, I don't know but I suspect that some percentage of failures are cranks that come from the factory on the outer edge of the specified runout; some percentage are probably self inflicted by owner abuse in the form of lugging, burnouts, wheelies, engine braking, etc. Some of those failures, maybe, could have been avoided if the left side Timken bearing had not been dropped by the factory 20 years ago. IIRC, the MoCo stiffened up the left side roller bearing in '09 to make it more robust but most would agree still not as robust as the Timken left side bearing.