As many of you already know the new for 2006 Primary Chain Tensioner tends to over tighten the primary chain and takes out the inner primary bearing. Previous Primary Chain Tensioners were manually adjusted and locked down. Harley Davidson's fix for 2007 and up was alignment dowels between the inner primary housing and the transmission housing but the later model bikes are still eating up inner primary bearings as well as main drive gear bearings. There are several different aftermarket Primary Chain Tensioners, each with new problems.

When I opened up my primary to replace the inner primary and main drive gear bearings the primary chain was tight with almost no deflection. So I removed the spring, installed the Primary Chain Tensioner, set the deflection, removed it and primed and bonded the ramp in with silicone. Used .040" safety wire, four strands where the spring was and safety wired that to the Tensioner body, even though the bonding seems to be rock solid.

5/8" to 7/8" cold is the non-auto Tensioner spec. I set it at 5/8" without compressing the springs in the ramp, compressing the springs it went up to a total of 7/8". I wanted to drill through the ramp right where that mark is in the photo below and just safety wire the ramp to the lower body of the Tensioner, but that material is pretty hard and I've seen too many varying results using different types of drills so I didn't bother. I put on about two hundred miles and the only thing I noticed is that it shifts a lot nicer.

 

I'm not familiar with how these are designed...

Are there serrations/pawls between the base plate and wedge/ramp that keep it from retracting under tension?

If the wire and silicone fail, can the ramp come out and destroy things?

What are the black curly cue bits on the wedge?

 

Watch these videos, and the one at the bottom of my previous post.






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You make me sooo glad I have the older manual adjuster. Does nobody make a manual for the later bikes? In the manual form it almost never needs adjusting anyway.

 

Baker, V-twin, Screaming Eagle (I think.)

 

Im starting to have issues after last years motor mods (96” to 110”, 135hp) and researching solutions. Im interested in modifying oem piece but not familiar with the device. What about cutting the spring thats on the rod by a few millimeters? Would that make the auto feature less aggressive? Maybe a few rounds of trial and error would be needed. Is it a captive spring? Does shortening it look possible?

 

That exactly what I've been doing.. I believe I took a 1/4" off. But can't remember exactly.. I do know there are no more issues with to right and finding neutral..

 

Another possibility to add to the list is an out of true crank causing the primary chain tensioner to over tighten:

@44:00 Primary Tensioner
Part 1 Harley Crankshafts and Comps - Darkhorse Crankworks - Kevin Baxter - Pro Twin Performance
20,756 views•Streamed live on May 2, 2020

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Part 2 Harley Crankshafts and Comps - Darkhorse Crankworks - Kevin Baxter - Pro Twin Performance
13,816 views•Streamed live on May 2, 2020

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