Originally Posted by Retrop

The MOCO's current position with the migration issue is to replace seals and spacers if the customer wants it. "If the customer wants it" would seem to indicate that they are not sure if this is the root cause or not. At this point I think they are just trying to placate people who are complaining about the issue. They know it is happening but don't really, really know what is causing it.

This migration problem was recognized about 5 months ago. If they think the seal might be leaking and pulling a vacuum in the primary which in turn is sucking transmission fluid in via the clutch push rod how does that explain how the fluid in the transmission somehow raises up high enough to travel down the push rod into the primary. Has anyone ever drilled a derby cover and actually attached a vacuum gauge to see if there is a negative pressure in there when the engine is operating? I remember it being discussed by a number of readers who had access to those tools but I don't remember anyone actually doing it and reporting what they found.
Anybody?

Originally Posted by QNman

What would cause a vacuum on the primary? The only moving parts are rotational... (just thinking out loud here). The only pressure in/out of the primary COULD be thru movement/actuation of the clutch, but how does that translate to pressurization of the primary case?

Originally Posted by bob2002

Its not pressure but a vacuum if that is what is happening

Originally Posted by QNman

Sorry, that's what I meant. I corrected it.

Originally Posted by bob2002

I know

Originally Posted by FredCa

Not sure what to think?

When I did my 5K service, I saw evidence of fluid transfer. When I took off the derby cover, the fluid was up to the level of the opening. A little bit ran out and dripped on the floor. This didn't surprise me as I had needed to add some fluid to the transmission during the period between the 1k and 5k services.

My wife and I just got back from a 4 day weekend of loaded touring in the mountains and some pretty hard riding of more then 1,500 miles. I dreaded checking the transmission when we got back. Much to my surprise when I did check it, it was still full. I see no indication of any transfer. If fluids are still being transferred, the rate of transfer has at least slowed down.

I think this is good news. Is anyone else experiencing anything similar?

Originally Posted by QNman

What would cause a vacuum on the primary? The only moving parts are rotational... (just thinking out loud here). The only pressure in/out of the primary COULD be thru movement/actuation of the clutch, but how does that translate to vacuum of the primary case?