M8 trans fluid leaking in primary

[FSG]

no slingers on hydraulic clutches as there's no room for them

So is this possible in Hyd twin cams also?

no slingers in TC's either

[FSG]

I wonder if the Slave is acting like a pump and pushing the trannie fluid through the mainshaft when it's actuated.   

[Bike31]

Surely there's an oil seal on the pushrod?

[rbabos]

Surely there's an oil seal on the pushrod?

No because the primary vents through the space between the pushrod and hole in the shaft, then out the trans vent.
Ron

[rbabos]

I wonder if the Slave is acting like a pump and pushing the trannie fluid through the mainshaft when it's actuated.   

Should be a 0 clearance situation but the oil capture area might be higher area then say the ramp method. Hard to say for sure but any oil hanging around could be screwed in through the shaft space. Does it happen while just cruising or is it a longer term effect when the pushrod and shaft operate at different rpms, like when the clutch is pulled in and one or other acting like a lead screw pulling fluid in? You know, like those spiral groove oil seals but a reverse effect in this case. How smooth is the hole inside the main shaft and the spiral line direction from drilling it? Just cool "Potty mouth" to ponder.
Ron

[1FSTRK]

Well a good look at what is different between the M-8 parts and the parts from the previous thirty years that HD has run it this way.

[rbabos]

Well a good look at what is different between the M-8 parts and the parts from the previous thirty years that HD has run it this way.

In that case we would have been reading this 30 years aga, right? Something is different. Haven't heard of any other models with hydro clutch doing it, or they never noticed.
Ron

[1FSTRK]

Well a good look at what is different between the M-8 parts and the parts from the previous thirty years that HD has run it this way.

In that case we would have been reading this 30 years aga, right? Something is different. Haven't heard of any other models with hydro clutch doing it, or they never noticed.
Ron

So we agree, just have to find out what it is.

[Bike31]

2016 > 2017 the secondary hydraulic clutch activator and right bearing housing are different P/N's: http://www.docshd.com/OEMpartfinder.htm Plus 2 P/N's for 2017.

I might be FOS so check it out.

[Sunny Jim]

Just checked my Gearbox oil, cold on side stand as per the book. dip stick shows zero oil.
Personally, I am pissed off.

[RXBOB]

Yeah checked mine today with 5000ks on it Primary High and the gearbox at the add mark, I have emailed my dealer and will see what he comes back with. I will drain next week on days of and measure what comes out fill and monitor again
here is a couple of pics











EDIT: imgur rather than photobucket

[Bike31]

HD Forums has a thread on this under their M8 section. SC says it's so and rpm related.

Gary

[rbabos]

HD Forums has a thread on this under their M8 section. SC says it's so and rpm related.

Gary

Yes, I saw that. He claims they will all do it if operated above 3500 rpms. The ones that seldom venture there will not see it , or very little. That's a BS way to operate a bike, no matter how one slices it. Fearing oil transfer always on the back of your mind on those 5+k shifts.
Ron

[Durwood]

HD Forums has a thread on this under their M8 section. SC says it's so and rpm related.

Gary

Yes, I saw that. He claims they will all do it if operated above 3500 rpms. The ones that seldom venture there will not see it , or very little. That's a BS way to operate a bike, no matter how one slices it. Fearing oil transfer always on the back of your mind on those 5+k shifts.
Ron

Agreed 100%.

I called my local dealer and let him know what was happening, hopefully if enough of us complain they will do something to fix the issue.

[motorhogman]

That stinks !  OK I give up.. Why does the trans have to vent through the primary.. I'd be drilling a hole somewhere top side on the trans and installing a fitting with a felt filter and small hose to vent the dang thing.. To simple ? 

[Bike31]

Mentioned above is that the primary vents around the clutch pushrod then trans and then out the rubber elbow. Don't know as I've never had one apart.

But what air goes out when the primary's heated has to come back when cooled. Any oil pooled nearby 'may' get sucked in.

Lowering the trans fluid can't be good...same for primary overfill and clutch plate soaking.

Somebody's in trouble who designed the new system as I've not heard of pre-17's with hydraulic clutches but w/o a slipper clutch unit having the problem.

Gary

[Durwood]

That stinks !  OK I give up.. Why does the trans have to vent through the primary.. I'd be drilling a hole somewhere top side on the trans and installing a fitting with a felt filter and small hose to vent the dang thing.. To simple ?

The M8 trans is vented through the top cover just like it's predecessor and the tube is the same size as the Twin Cam six speed, it is located in a different spot on the cover, but I can't see why that would matter.

[motorhogman]

That stinks !  OK I give up.. Why does the trans have to vent through the primary.. I'd be drilling a hole somewhere top side on the trans and installing a fitting with a felt filter and small hose to vent the dang thing.. To simple ?

The M8 trans is vented through the top cover just like it's predecessor and the tube is the same size as the Twin Cam six speed, it is located in a different spot on the cover, but I can't see why that would matter.

OH  OK   I just figured it wasn't vented.. So vent the primary separately and seal the systems from each other with this hydraulic clutch system..??

I know my 5 speed is vented on the left rear side of the cover.  Cable actuated clutch and has never had an issue.

Is there any reason not to vent the primary separately ?

TY,  I don't have an M8 but really do enjoy reading all the stuff You and others are posting here. Great info on the "new kid" on the block

[rbabos]

That stinks !  OK I give up.. Why does the trans have to vent through the primary.. I'd be drilling a hole somewhere top side on the trans and installing a fitting with a felt filter and small hose to vent the dang thing.. To simple ?

Primary vents through the trans between the pushrod and hole space in the shaft. All this air in and out from both primary and trans, from hot cold expansion and cooling of air vents at the top of the trans.
To run a form of seal on the pushrod, as seperate primary vent would be needed. Let's see what MoCo comes up with.
Ron

[HV]

A labyrinth Seal of some sort may work 

[Bike31]

Something changed between 2016 and 2017. I see several parts of the transmission now have different numbers. Same for the clutch. Lots of dyno runs on both TC's and M8's at higher rpms so that's not new.

Maybe put a clear derby cover on and watch? Or at least regularly keep track of the trans fluid level.

[04 SE Deuce]

The problem is real,  I talked to Bill Greenrock that started this thread,  he knows what he's doing and has had to adjust his levels several times.

[Sunny Jim]

Maybe Wes (Tattoo) could chime in. It is definitely an issue the MOCO will have to attend.

[rbabos]

Look at the bright side. The trans dipstick now has a purpose.
Ron

[1FSTRK]

The thing to remember is HD has used this vent system on all these bikes starting from the mid 1980's when they went to the wet clutch, so they just need to Identify what they changed on the M-8 that is driving oil from the trans into the primary at higher rpm.

It would be a step backward and I am not sure if there is room inside the M-8 clutch to do it but on the old dry clutch Harley's up through the early EVO's or when a primary belt drive is installed the clutch hub nut gets bored and a seal is installed in it. If this was done you would just need to vent the primary. It will be interesting to see if they figure it out or patch it by going backward.