After nearly 8 years of these fluid migration threads, I am to the point where I think of this

 

Blame the MoCo, not the poster.....

 

I wonder why only some might need the vent, building pressure, and others not?
I wonder if OP found out anything?

 

I havent gone in to a shop yet. Should do that next week. My mechanic was ordering the vent kit for me. I also went ahead and bought a fat clutch rod to see if that helps too. Ill update when I get more info.

 

[QUOTE=Chuck1;21781335]I wonder why only some might need the vent, building pressure, and others not?

Anyone? I have researched it some and nothing official, what causes this in a small amout of bikes and different miles. 🤔

 

I can't speak for ones on M8s. But i put a little anti seize on derby and inspection covers.
[QUOTE=Chuck1;21782462]One theory I heard of why it happens on touring bikes more, is they tend to have long days of riding, and get hotter.

 

[QUOTE=Rounders;21782473]I can't speak for ones on M8s. But i put a little anti seize on derby and inspection covers.
Oh, I have heard the hearsay stuff. So far it's a phenomenon.

 

So, after further investigation, from what I understand, Harley COULD NOT RECREATE THE RARE OCCRANCE of M8 migration of tranny/primary! So maybe it is a phenomenon. So they came up with one little fix, a slinger. It worked somewhat, then they came up with the vent kit. Neither recommended for a prevent, only to fix the rare occurrence of the migration after properly checking fluids a few different times after certain mileage.

 

So, after further investigation, from what I understand, Harley (found the cause but it would cost too much to do the redesign, and production change to do a proper fix. Plus that would leave them liable for any of the "problem designs" still out there for future oil migration. Harley decided to find a band-aide fix that would work in the vast majority of cases to limit their warranty repair costs and future liability) of M8 migration of tranny/primary!

I fixed it for you....