2015 road glide - transmission fluid migrating into primary

[Shadowbennie]

Ugh, here am I am, in the middle of a camchest rebuild (thread in twin cam section) when I notice that over the last couple of days that I have some fresh tranny lube (I use belray twin cam tranny fluid - red in color) seeping out of my clutch pack. At first I didn't notice the first sign, which was a puddle of trans fluid on the floor, I thought it was just runoff from the crossmember as I just recently changed the tranny fluid. But then on Sunday when I got done spinning the motor to position the pushrods to cut them, I noticed a little red fluid on the outer ring of my clutch basket. I thought that was odd, so I wiped it off. I just got home from work and checked it again tonight, and wiped my finger along the bottom of the clutch pak, and there is more there. Shite!

A little background as to why I even had my primary cover off in the first place.

This past year I had started noticing a random "clatter" that I don't remember being there before. No other grinding or whirring noises that I noticed, just this random clatter that would happen at idle, clutch lever pulled in or out, in gear or in neutral. Bike seemed to shift normally, or at least nothing was happening shifting-wise that I noticed or would cause concern anyway.

It would go away under power, unless I accidentally would lug the engine, then it would happen as well. I figured either something is loose (floorboard, bracket, etc), or it's just starting to get noisy since it's a twin cam with 48k miles. I've taken a peek at the chaincase this winter to look for anything that would stand out as an obvious problem, (like loose compensator nut - but that was tight) and everything else feels tight, no visible abnormal wear on what I can visually see. But, now i found this fluid migrating. I'm thinking main shaft bearing and/or seal - bearing because of the "clatter", and seal being more obvious because of the fluid showing up. HELP! Thoughts? Experiences?

I guess I've punished this poor bike more than I thought- and I don't even really ride her that hard!

[PoorUB]

Is the motorcycle parked on the jiffy stand? If it is of course some transmission fluid will drip out of the main shaft. You do realize the primary vents through the main shaft and into the transmission, correct? Was any transmission fluid migrating before, while riding?

I think you are worrying about nothing.

[Shadowbennie]

It's been on the lift for about a week or two, so it's been sitting level for quite some time. But I did have the outer primary off when I changed the tranny fluid and it did sit on the side stand for a bit after that until I put it on the lift. So are you saying that because the primary cover is off, and it was on the side stand, that the lack of sealing pressure by having the cover off can cause the transmission fluid to migrate along the main shaft toward the primary because of how the primary vents to the transmission?

I can't say with 100% certainty that no migration was happening last year during riding season, and I guess if there was, it wasn't enough to notice. But it's also not something I was looking for. I should clarify, in case it makes a difference, but the fluid isn't dripping out of the end of the main shaft that I can tell, it appears to be coming out from within the clutch plates

[PoorUB]

The only place transmission fluid can leak into the primary is through the main shaft. If it leaks any where else it will hit the ground. The transmission is not over filled, is it?

Put back together and ride it, but watch the transmission lube level just to be safe.

[Shadowbennie]

I'll double check the level, but when I drained it - is was damn cold out, like teens for highs, but I let it drain for at least a day and I think it may have been two. Then when I filled it I used the typical amount - 1 qt. as I've always done without issue.

I suppose maybe there was still some trapped in there and I over-filled it....maybe I'll drain it again and wait until we get some warmer temps to re-fill.

I had read that the shift lever shaft seal might be a possible culprit as well, but that spot looks like it's more offset from the clutch hub in the case, so I'd see fluid sitting at the bottom of the inner primary rather than in the clutch plates.

I'll also check that the transmission vent hose isn't blocked, but since I haven't ridden the bike since last November, I don't think that's the problem - no pressure to build up.

[Mick0311]

I just had my primary off and did see a little transmission fluid (Redline) coming through the clutch pushrod.
Not enough to puddle under the bike though.

[Shadowbennie]

I just had my primary off and did see a little transmission fluid (Redline) coming through the clutch pushrod.
Not enough to puddle under the bike though.

Hey Mick,

Yeah, I was reading your thread as well to try and find out whether what you were finding with your leak matched what I'm seeing. My puddle came from slow dripping off of the clutch pack, which occurred over a couple week timeframe, but I just hadn't noticed it until I moved the lift around on Sunday to tear into the cam chest.

but given the position of the clutch pushrod in relation to where I'm seeing fluid, it doesn't seem a likely culprit - mine appears to be seeping into the clutch plates and is dripping out of the plates & basket

[Mick0311]

Have you removed the clutch to see if the fluid is travelling down the OD of the mainshaft?

We have hydraulic clutches. Is it possible that the leak is coming along the pushrod, hitting the release plate causing it to pool up and then filter out the clutch discs?

[PoorUB]

That is the only way it can happen.  If you have another way to get transmission  oil to the clutch  I  would like to hear it.

[Shadowbennie]

Have you removed the clutch to see if the fluid is travelling down the OD of the mainshaft?

We have hydraulic clutches. Is it possible that the leak is coming along the pushrod, hitting the release plate causing it to pool up and then filter out the clutch discs?

Based on what I now know about the interface between the two, some extra leaking through the pushrod seems like a possibility.

I have not removed the clutch pack yet, was going to tear into it if the general feedback was that there was a common seal that tends to fail, but, because there really are only two spots transferring can occur, that's set my mind at ease.

UB has the easiest item to check first that I'll try - make sure it's not overfilled. It could be, after all, it was only 10 degrees or so when I drained it, and maybe it was so cold not all of it drained out. Then if it's not that, I could pull the clutch pack and check for an overly excessive leak at the pushrod.

I feel like I can step back from the ledge now - this development just caught me off guard and made me push the panic button a little because of that clattering I had been hearing late last summer/fall, plus the "leak" just started happening about the same time I've been doing all the cam chest stuff.....

I'll still want to keep an eye on fluid levels and look for anything odd on the magnets at fluid changes, but I'll confirm these two things I need to look at and button it up for riding season - if that ever gets here!

[Maddo Snr]

/quote]

Then when I filled it I used the typical amount - 1 qt. as I've always done without issue...I suppose maybe there was still some trapped in there and I over-filled it...

1US quart (950ml) will take the oil level way over the actuator rods' passage hole. Of course it will weep slightly if the bike is level on a lifter. Normally on the jiffy the RHS side of the gearbox has a much lower oil level (under the cross shaft orifice).

On M8s I've been milling a drain downwards from the S/C cavity and a vent upwards into the gearbox void to stop the S/C pressurising the cross shaft cavity with oil. I also drill a drain from S/C diaphragm face to the gearbox void which stops that cross-weeping dead in its tracks.

My bikes are never left on the jiffy at home, always on the lifters, hence how I spotted this.


There's no issue here at all Bennie IMO. 27-28 oz fill in the gearbox will solve it, that's all M8s run.

[Shadowbennie]

/quote]

Then when I filled it I used the typical amount - 1 qt. as I've always done without issue...I suppose maybe there was still some trapped in there and I over-filled it...

1US quart (950ml) will take the oil level way over the actuator rods' passage hole. Of course it will weep slightly if the bike is level on a lifter. Normally on the jiffy the RHS side of the gearbox has a much lower oil level (under the cross shaft orifice).

On M8s I've been milling a drain downwards from the S/C cavity and a vent upwards into the gearbox void to stop the S/C pressurising the cross shaft cavity with oil. I also drill a drain from S/C diaphragm face to the gearbox void which stops that cross-weeping dead in its tracks.

My bikes are never left on the jiffy at home, always on the lifters, hence how I spotted this.


There's no issue here at all Bennie IMO. 27-28 oz fill in the gearbox will solve it, that's all M8s run.

Thanks Maddo - I'll triple check in my service manual, but I think the rushmore bikes do take a full qt of fluid - with that said though, the trans could've been overfilled due to the cold and not draining completely, plus I've really never had my bike on the lift for the period of time that it has been this winter - it's always on the jiffy stand during the winter and never sits for more than a day or two in the summer (I ride to work every day and most weekends, at least one of the two days)

I'm likely just gonna drain the trans completely once it warms up so the gear lube flows better and start over with the fill, stop at around 28 oz, and check the level. Button it up and ride it for a while and keep a very close eye on the trans fluid level.

[PoorUB]

Why drain it, it has a dip stick. Check the level, keep an eye on it, but I believe you are worrying about nothing!

[Maddo Snr]

Why drain it, it has a dip stick. Check the level, keep an eye on it, but I believe you are worrying about nothing!

Pretty much how I see it UB but consider this...cable and hydraulic clutch bikes have identical gearboxes and dipsticks BUT different gearbox oil volumes.
Ergo, the same fill volume will create differing oil heights.

The MoCo aren't too switched on with this.

Primary...same issue on M8s. The factory fill-spec by volume will OVERFILL slightly compared to factory fill-spec by height. Very strange goings-on. 

[Shadowbennie]

Why drain it, it has a dip stick. Check the level, keep an eye on it, but I believe you are worrying about nothing!

Pretty much how I see it UB but consider this...cable and hydraulic clutch bikes have identical gearboxes and dipsticks BUT different gearbox oil volumes.
Ergo, the same fill volume will create differing oil heights.

The MoCo aren't too switched on with this.

Primary...same issue on M8s. The factory fill-spec by volume will OVERFILL slightly compared to factory fill-spec by height. Very strange goings-on. 

well, yes, it is overkill to completely drain it, so I decided to forego the complete drain and pulled a few oz's out with a mity vac to get it at the add mark as it sits on the lift. I'll keep an eye on the clutch side and have a clean rag sitting under where it was dripping to gauge whether it slows down or stops and once I get the rest of the chaos settled with my engine work (that's a whole different shitshow) I can button it up and wait for spring to arrive to get it on the road to test.....