Is there a common seal between the primary and transmission on TC's.

99 RK. Changing the oil and PER A PREVIOUS HD TECH, was advised I could use TYPE F tranny fluid in primary. When I drained the tranny, it came out milky pink color. I used Formula 1 last time I changed the oil. My 2010 E.G. was the same way....

 

Jeff, there is an oil seal between your primary and the crankcase, but not with the transmission casing. There is an air gap between those, where your drive belt and pulley live, but with seals in both primary inner and trans casing. I can't see how tranny oil can get into the primary, or the other way around.

 

The only way oil can migrate from the tranny to the primary is through the clutch pushrod shaft. There is any seal. In fact the primary vents to the tranny. Migration is an issue with M8s as they have hydraulic clutches and don't have a oil flinger. The cable clutches usually don't have this problem but could possibly if the tranny vent tube was plugged and or the motor crankshaft seal was sucking air from the primary. I would suspect that you main issue is not getting the primary hot enough during rides and some moisture is building up in the primary.. Probably won't be as pink as with redline. If you don't do you own services, it's possible that someone that service the bike used ATF..

 

Okay this was my bonehead post I went back and checked I use the redline oil in my transmission

 

 

Well I screwed up. I read the OPs issue as oil transferring from the tranny to he primary when he was questioning the opposite. Good ol' dyslexia..