Is it possible for trans fluid to migrate into the primary? I had to go into my primary to replace the inner seal and I notice I could smell gear lube on the drain plug and the fluid was real dark now I put all new fluids in the primary and gear lube in the trans a month ago. I'm not sure why the fluid was so dark the only thing I did in the primary was I put a set of Kevlar clutch plates in the clutch. Could they have done that to the fluid maybe being new and breaking in? Any ideas out there

 

The primary and tranny share the air. The adjustment screw in the clutch is flat sided so that air pressure in the primary can be evacuated through the tranny via the tranny's vent tube. I don't believe that there is enough tranny fluid to use that clutch rod tube as an access point for tranny fluid to get into the primary.

Dark primary fluid means it's just dirty IMO. Mine gets black between 5,000 mile changes.

 

I realistically had less than 500 miles on the fluid my guess is the new Kevlar clutch plates had something to do with fluid color. So now I know the primary vents through the trans btw I did check the trans vent tube it didn't feel spungy and I was able to run a zip tie through it.

 

What I found out was the Kevlar discs are somewhat dirty I you will call them that so a early fluid change is recommended once all the newness is off . And they do have a strange smell during this period. So I feel better knowing that

 

I'm certain that it's all good. Enjoy!