M8 trans fluid leaking in primary

[PoorUB]

If the main gear inner seal leaks it leaks to the ground unless something has changed. I be only connection between the primary and transmission is the hollow main shaft.

You are right. I was thinking unclearly. Modified my post so I don't sound like a complete moron.
Ron

Too late, we figured that out a long time ago! 

[rbabos]

If the main gear inner seal leaks it leaks to the ground unless something has changed. I be only connection between the primary and transmission is the hollow main shaft.

You are right. I was thinking unclearly. Modified my post so I don't sound like a complete moron.
Ron

Too late, we figured that out a long time ago! 

That's two for you today. I will get even when you least expect it.
Ron

[96349]

If run hard enough, long enough, the trans/shifting will let you know there's a problem.

That is exactly how I discovered the problem. The transmission was problematic in shifting-all of a sudden.
I popped the derby cover off to take a peak and there was way, way more fluid in there than there was supposed to be. I  sucked out the excess to where it was supposed to be and buttoned it up. Took the bike out for a road test and it shifted normally again. While I was out riding I was trying to come up with a scenario as to where the excess Formula+ was coming from, and could not find one in my head. When I got back from testing, just for the hell of it, I checked my transmission level. Whoa! The Formula+ was way low on the stick. It was not until 3 hours later that I started connecting the dots in my head and wondered if I poured the excess fluid I took out of the primary back into the transmission would it be the correct amount. I did, and it brought the fluid right up to the mark on the X. That was back in early May of 2017. This happened again 3 weeks later, although not as much fluid was transferred that time. I have not had an M8 transmission apart yet so I am at a loss as to how the fluid is moving. The push rod seems like it might have something to do with it.

[04 SE Deuce]

It's obvious that the trans oil is migrating to the primary...it just took some of the internet crowd 4-6 months to accept reality and stop arguing.

I have heard of guys pouring the excess primary oil back into the trans...I wouldn't do this as the primary is a dirty environment with a lot of clutch material debris that I wouldn't want in the trans bearings.

I would add new clean oil to the trans and save the excess primary oil in a jug to pour on the service desk at the dealer if they required additional evidence for a complete understanding.

[98fxstc]

I would add new clean oil to the trans and save the excess primary oil in a jug to pour on the service desk at the dealer if they required additional evidence for a complete understanding.

[HDDOC]

I have a 2017 Tri and after reading this post I have been checking the trans and primary with only 1500 miles on the Tri I have no problems yet . Will continue to check it.  Thanks Doc

[spook]

So if HD runs Syn 3 in both the trans and primary how can one tell if the trans syn 3 is migrating except for the lowering of the trans level indicator?  Wonder what would happen if one was running a trans specific fluid like Redline and the migration occurred.  I am taking my 17 CVO in for a small oil leak tomorrow and will be interested in seeing what the chief wrench has to say about this issue. 

[PoorUB]

Wonder what would happen if one was running a trans specific fluid like Redline and the migration occurred. 

Formula + is HDs recommend tranny fluid, other than Syn 3, and they recommend it for the primary too. Unless your tranny fluid has some additive that will mess with the clutch there should not be any issue.

[hd06]

 So I guess nobody has figured out how trans fluid got in the primary   

[PoorUB]

So I guess nobody has figured out how trans fluid got in the primary   

Just the opposite, everyone knows how, we just want to know why.

[spook]

I usually run Redline Shockproof  in the trans and Redline primary stuff in the primary.  Mobile one for the oil.  Will see what the wrench has to say about that combo....

[hd06]

 OK fill me in how did it get in there.

[1FSTRK]

OK fill me in how did it get in there.

As stated a few times it travels through the clutch rod hole in the mainshaft. The question is why after 32 years of different versions of this system does it now transfer oil?

[HV]

Lets not forget too ....this is not in any way a huge issue with the M8s ...Aside from here ....Ive heard of NONE from any other Dealer Techs ...and have found none of our Customers with any issues  .....

[04 SE Deuce]

Lets not forget too ....this is not in any way a huge issue with the M8s ...Aside from here ....Ive heard of NONE from any other Dealer Techs ...and have found none of our Customers with any issues  .....

Are your techs actually checking levels before they drain fluids?

Does your dealership do thorough/extensive Dyno tuning?

Are you saying the MOCO hasn't informed the dealers,  bulletin or other?

[harleytuner]

I just put one on the dyno for tomorrow mornings tune, his trans is at the add mark and his primary is up as well.  The dealer wasn't aware of this issue until I called them. 

[HV]

Are your techs actually checking levels before they drain fluids?  Yes since the issue came up on here

Does your dealership do thorough/extensive Dyno tuning?  NO ..Are you saying only Dynos cause this issue ?

Are you saying the MOCO hasn't informed the dealers,  bulletin or other?  That is Correct

[Bike31]

It's been noted RPM's cause the issue. Run it like Briggs & Stratton intended.

[Sunny Jim]

Possibly Darren and co could give us some insight as to what they have been doing to remedy this fault.

[harleytuner]

Possibly Darren and co could give us some insight as to what they have been doing to remedy this fault.

The MoCo is  sending out complete transmissions, cases and all.  A little clearencing on the existing cases has greatly reduced the fluid migration is what we're finding on our testing. 

[blackhillsken]

The MoCo is  sending out complete transmissions, cases and all.  A little clearencing on the existing cases has greatly reduced the fluid migration is what we're finding on our testing.
[/quote]

What area have you been clearencing ?

[HD/Wrench]

we lost volume in the new case . Funny its not a issue from most dealers ... but hey here is a new trans .. That I like instead of saying well here is a fix and running ti low on fluid caused no extra wear .. That is great to hear

[HV]

Gotta eat my words...guess what I found this AM ...YUP   Low Tranny High Primary        

[Mark P]

Okay, so what I'm thinking after all this is the trans vent is not venting so the trans is pressurizing. Time for a screamin eagle top cover with a high volume vent. For performance applications of course

[Mark P]

Looks like the trans vent is a rubber hose with with a flat rubber piece that lands on the inside of the top cover. Has anyone tried pulling the vent hose out (from the inside of the top cover) and just run it open to see if it makes a difference. Maybe the flimsy piece of rubber hose is heating up and collapsing.