Have read many threads on transmission fluid with members indicating their transmission oil "looked as good as when I put it in 5,000 miles ago". Mine doesn't. Mine magically changes color. What might be causing my Formula+ to turn dark, almost black, in color. I'm guessing a leak somewhere, but no oil on the floor or anywhere on the bike. Crankcase oil and transmission oil levels remain right where I filled them to at last change. First noticed it shortly after having SE compensator installed, but could have been that way before the comp. swap. I know I'll have to open the primary, but which bearings/seals would most likely cause a leak into the transmission?

 

The shaft behind the clutch

 

Thanks for the reply. Was hoping this was a common and easily fixable problem.

 

Most all problems are common, most are not easy to fix.
Base gaskets on the evo., inner cam bearing on same.
Cheap bearing on the 08/09, weaak compsator on same!
Now I have a bearing that is grawling in the lower case?
Always SOMETHING............Tenn.

 

It's the same with non HD bikes too....it's the parts they put in the bike from questionable sources.

 

The primary vents to the transmission thru the clutch push rod. The oil sump on the bottom of your transmission also vents to the transmission. The three actually all share that rubber hose vent. On a Softail, that is what that third hose coming off the oil tank is going. If your oil is turning truly black, it could be your stator is getting hot from some shorted area. You should be able to smell that. Unhook the three wires coming from the stator at the regulator and use you ohm meter to frame ground and see if any are going to ground.

 

Don't think it's the stator, I've smelt that smell before and I don't smell it now. Formula+ from the tramsmission smells like gear oil like it's supposed to, but it's darker in color than it oughta be. Either crankcase oil (Mobile1 V-Twin) or Primary oil (H-D Formula+) is seeping into my transmission and changing the color of my transmission oil. No leaks on garage floor or bottom of bike. If it was just a slight color change I wouldn't worry about it, but this is a fairly dramatic change from "light honey-gold" to "rootbeer" color.

 

Primary fluid normally darkens with usage. Just a common occurance due to the oil bath clutch.
The transmission fluid should drain out in nearly the same condition as it went in - nothing much to dirty it up if everything is 'right'.
I use ATF in the primary and Mobil GL5 Syn 75/90 in the trans. The ATF is of course red in color and the Mobil 75/90 is nearly clear. The primary gets drained every 10K mi. and the trans every 20K mi. and they always drain out looking pretty good, particularly the trans fluid.

 

I miss read your post. I thought you were saying oil was dark in primary. Now I realize you are saying oil is dark in transmission. I would think if your transmission is getting primary or engine oil, it would show up on the stick level. From what I understand there is no seal on the clutch pushrod and that the only thing that keeps fluid from migrating is the rotation direction. I have see post on here that if the primary is way over filled, it can get in there. It's real easy for engine oil to get into primary if the crank seal goes behind the stator. Do you see much fur on the transmission magnet? Why are you opening the primary? If the levels are OK, I would think that would be a waste of time. There are no transmission seals inside it. I have seen were if you run Formul+ in transmission for a long time and switch to SYN motor oil, the oil will be dark for the first few changes since I think it's designed for a filtered system and to keep stuff in suspension more then a strictly gear oil. So it cleans the dirty walls. I personally do not change oil but once a year (sometime longer since I do not do a lot of miles) but I just change all three when I do since ever time I have been in primary it is full of chips and the way the shift dogs bang on a 5 speed, the transmission is too.

 

sorry but I'm confused , you are saying that your formula plus is getting dark and talking about your trans and say that your motor and trans levels are good , if you are meaning your primary it will get dark from your clutches normal wear or they may be slipping , why do you think there is a leak ?