M8 trans fluid leaking in primary

[04 SE Deuce]

The saga continues...here's a thread on one of the latest attempts at a cure: https://www.hdforums.com/forum/milwaukee-eight-m8/1219654-the-fix-is-in.html

Last few pages, Bruce/Max/Admiral is getting involved...machining the nuts.

[04 SE Deuce]

delete

[HD/Wrench]

The saga continues...here's a thread on one of the latest attempts at a cure: https://www.hdforums.com/forum/milwaukee-eight-m8/1219654-the-fix-is-in.html

Last few pages, Bruce/Max/Admiral is getting involved...machining the nuts.

aware of this . At least things people are working towards a fix I know Steves bike is very bad on transfer and its been well documented .. Its odd how some may only do it to a small % and others are pushing it out at a excessive rate .

[rbabos]

Well, stock primary oiling system on some year Shovelheads used a sealed pushrod nut arrangement also. What's old is new again. It's a shame customers have to fix HD fk ups while they sit back and do nothing.
This has gone on way to long now.
Ron

[1FSTRK]

The saga continues...here's a thread on one of the latest attempts at a cure: https://www.hdforums.com/forum/milwaukee-eight-m8/1219654-the-fix-is-in.html

Last few pages, Bruce/Max/Admiral is getting involved...machining the nuts.

I may have missed it but did anyone see in that thread how they plan to vent the primary after they totally seal off it's only vent?

[Durwood]

The saga continues...here's a thread on one of the latest attempts at a cure: https://www.hdforums.com/forum/milwaukee-eight-m8/1219654-the-fix-is-in.html

Last few pages, Bruce/Max/Admiral is getting involved...machining the nuts.

I may have missed it but did anyone see in that thread how they plan to vent the primary after they totally seal off it's only vent?

He drilled a hole in the top of the slave cylinder.

[Durwood]

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[Sunny Jim]

So what was the outcome?

[rbabos]

Not sure that hole does anything. Only direct line from primary to trans is the center hole in the main shaft.  Every thing else is sealed to keep each fluid in their own spaces.  A separate vent line would be needed from inner cover, t'd into the existing trans vent hose or run a hose higher up with a small filter. Between the sealed nut for the pushrod and separate vent, problem solved. Same deal worked on the Shovelheads like 40+ years ago, other then the vent connected to the oil tank high point. Build it right, then HD can steal the idea. Not like they haven't done that before.
Ron

[08flstf]

Does anyone have any idea what percent of the bikes transfer vs what percent don't? I know some people never check their levels and are oblivious but I have a few friends that have m8's and I've mentioned this to them. They've checked their levels and they're normal.

[Durwood]

Not sure that hole does anything. Only direct line from primary to trans is the center hole in the main shaft.  Every thing else is sealed to keep each fluid in their own spaces.  A separate vent line would be needed from inner cover, t'd into the existing trans vent hose or run a hose higher up with a small filter. Between the sealed nut for the pushrod and separate vent, problem solved. Same deal worked on the Shovelheads like 40+ years ago, other then the vent connected to the oil tank high point. Build it right, then HD can steal the idea. Not like they haven't done that before.
Ron

I believe it does. The primary vents through the main shaft then to atmosphere through the hole in the slave/actuator vs going into the trans and venting out of the hose in the top cover which appears to be similar in size.

[HD/Wrench]

I know of one bike that they vented the primary .. Much like the trans put a small K&N filter on it .. I do not know if it solved the issue .. It was on the bike when I tuned it no issues / no transfer .. But long term ?? no idea bike has never been back ..  Tune was  sub contract  to me ..

[rbabos]

Not sure that hole does anything. Only direct line from primary to trans is the center hole in the main shaft.  Every thing else is sealed to keep each fluid in their own spaces.  A separate vent line would be needed from inner cover, t'd into the existing trans vent hose or run a hose higher up with a small filter. Between the sealed nut for the pushrod and separate vent, problem solved. Same deal worked on the Shovelheads like 40+ years ago, other then the vent connected to the oil tank high point. Build it right, then HD can steal the idea. Not like they haven't done that before.
Ron

I believe it does. The primary vents through the main shaft then to atmosphere through the hole in the slave/actuator vs going into the trans and venting out of the hose in the top cover which appears to be similar in size.

What I'm missing is how that hole can connect to the space between the pushrod and bore of the main shaft, inboard of the seal install. All I see is pocket to pocket connection within the trans case itself which does not connect to the primary itself. Primary and trans are all sealed up, except for the space between the pushrod and main shaft bore. Adding a seal to the end of the pushrod to seal the gap between the two, air needs a path to continue someplace. I must be in one of my dense moments and  missing a connection for this hole to the primary itself. The sealed pushrod via nut and seal, good idea. The additional internal vent hole also good. There needs to be a second actual primary vent now that the original means has been sealed off.
Ron

[Durwood]

Not sure that hole does anything. Only direct line from primary to trans is the center hole in the main shaft.  Every thing else is sealed to keep each fluid in their own spaces.  A separate vent line would be needed from inner cover, t'd into the existing trans vent hose or run a hose higher up with a small filter. Between the sealed nut for the pushrod and separate vent, problem solved. Same deal worked on the Shovelheads like 40+ years ago, other then the vent connected to the oil tank high point. Build it right, then HD can steal the idea. Not like they haven't done that before.
Ron

I believe it does. The primary vents through the main shaft then to atmosphere through the hole in the slave/actuator vs going into the trans and venting out of the hose in the top cover which appears to be similar in size.

What I'm missing is how that hole can connect to the space between the pushrod and bore of the main shaft, inboard of the seal install. All I see is pocket to pocket connection within the trans case itself which does not connect to the primary itself. Primary and trans are all sealed up, except for the space between the pushrod and main shaft bore. Adding a seal to the end of the pushrod to seal the gap between the two, air needs a path to continue someplace. I must be in one of my dense moments and  missing a connection for this hole to the primary itself.
Ron

The space between the push rod and the main shaft opens up into the cavity that houses the actuator, and the primary pressure then exits the drilled hole.

[rbabos]

Not sure that hole does anything. Only direct line from primary to trans is the center hole in the main shaft.  Every thing else is sealed to keep each fluid in their own spaces.  A separate vent line would be needed from inner cover, t'd into the existing trans vent hose or run a hose higher up with a small filter. Between the sealed nut for the pushrod and separate vent, problem solved. Same deal worked on the Shovelheads like 40+ years ago, other then the vent connected to the oil tank high point. Build it right, then HD can steal the idea. Not like they haven't done that before.
Ron

I believe it does. The primary vents through the main shaft then to atmosphere through the hole in the slave/actuator vs going into the trans and venting out of the hose in the top cover which appears to be similar in size.

What I'm missing is how that hole can connect to the space between the pushrod and bore of the main shaft, inboard of the seal install. All I see is pocket to pocket connection within the trans case itself which does not connect to the primary itself. Primary and trans are all sealed up, except for the space between the pushrod and main shaft bore. Adding a seal to the end of the pushrod to seal the gap between the two, air needs a path to continue someplace. I must be in one of my dense moments and  missing a connection for this hole to the primary itself.
Ron

The space between the push rod and the main shaft opens up into the cavity that houses the actuator, and the primary pressure then exits the drilled hole.

Yes , I buy that with no nut modified for a seal as in stock setup. Seal changes everything from what I see. If the pushrod end is sealed, that hole does not really function, right?
Ron

[Durwood]

Not sure that hole does anything. Only direct line from primary to trans is the center hole in the main shaft.  Every thing else is sealed to keep each fluid in their own spaces.  A separate vent line would be needed from inner cover, t'd into the existing trans vent hose or run a hose higher up with a small filter. Between the sealed nut for the pushrod and separate vent, problem solved. Same deal worked on the Shovelheads like 40+ years ago, other then the vent connected to the oil tank high point. Build it right, then HD can steal the idea. Not like they haven't done that before.
Ron

I believe it does. The primary vents through the main shaft then to atmosphere through the hole in the slave/actuator vs going into the trans and venting out of the hose in the top cover which appears to be similar in size.

What I'm missing is how that hole can connect to the space between the pushrod and bore of the main shaft, inboard of the seal install. All I see is pocket to pocket connection within the trans case itself which does not connect to the primary itself. Primary and trans are all sealed up, except for the space between the pushrod and main shaft bore. Adding a seal to the end of the pushrod to seal the gap between the two, air needs a path to continue someplace. I must be in one of my dense moments and  missing a connection for this hole to the primary itself.
Ron

The space between the push rod and the main shaft opens up into the cavity that houses the actuator, and the primary pressure then exits the drilled hole.

Yes , I buy that with no nut modified for a seal as in stock setup. Seal changes everything from what I see. If the pushrod end is sealed, that hole does not really function, right?
Ron

It's not sealed from the cavity behind the actuator, I guess it's one of those things you need to see in person.

[rbabos]

Not sure that hole does anything. Only direct line from primary to trans is the center hole in the main shaft.  Every thing else is sealed to keep each fluid in their own spaces.  A separate vent line would be needed from inner cover, t'd into the existing trans vent hose or run a hose higher up with a small filter. Between the sealed nut for the pushrod and separate vent, problem solved. Same deal worked on the Shovelheads like 40+ years ago, other then the vent connected to the oil tank high point. Build it right, then HD can steal the idea. Not like they haven't done that before.
Ron

I believe it does. The primary vents through the main shaft then to atmosphere through the hole in the slave/actuator vs going into the trans and venting out of the hose in the top cover which appears to be similar in size.

What I'm missing is how that hole can connect to the space between the pushrod and bore of the main shaft, inboard of the seal install. All I see is pocket to pocket connection within the trans case itself which does not connect to the primary itself. Primary and trans are all sealed up, except for the space between the pushrod and main shaft bore. Adding a seal to the end of the pushrod to seal the gap between the two, air needs a path to continue someplace. I must be in one of my dense moments and  missing a connection for this hole to the primary itself.
Ron

The space between the push rod and the main shaft opens up into the cavity that houses the actuator, and the primary pressure then exits the drilled hole.

Yes , I buy that with no nut modified for a seal as in stock setup. Seal changes everything from what I see. If the pushrod end is sealed, that hole does not really function, right?
Ron

It's not sealed from the cavity behind the actuator, I guess it's one of those things you need to see in person.

Could be.
Ron

[kd]

After looking at the other thread that 01 SE Duece posted to, with the seal installed lip seal inward, I can see how a little positive pressure in the trans case would possibly increase the sealing ability of the lip seal in the mainshaft nut.

[Durwood]

After looking at the other thread that 01 SE Duece posted to, with the seal installed lip seal inward, I can see how a little positive pressure in the trans case would possibly increase the sealing ability of the lip seal in the mainshaft nut.

I agree.

[rbabos]

After looking at the other thread that 01 SE Duece posted to, with the seal installed lip seal inward, I can see how a little positive pressure in the trans case would possibly increase the sealing ability of the lip seal in the mainshaft nut.

There should be no pressure. Trans is vented and with that additional small hole in that cavity the whole box should be static air, just like the primary as it vents from heat expansion.
Ron

[Slyde]

Ron, I believe the primary vents directly to the slave cylinder cavity then out the drilled hole to the side cover.

Brian

[kd]

My point was meant to say that there likely is a little tolerance to leaking if transmission case pressure "should" occur. IMO 

[rbabos]

Ron, I believe the primary vents directly to the slave cylinder cavity then out the drilled hole to the side cover.

Brian

Yes, I understand that and that's fine. It's with the addition of this seal, primary venting is stopped, assuming the seal is actually sealing.
Ron

[rigidthumper]

Yes, I understand that and that's fine. It's with the addition of this seal, primary venting is stopped, assuming the seal is actually sealing.
Ron

Correct, this seal is designed to isolate the trans fluid from the clutch slave cylinder.




Now the primary is vented through the gap between the nut and the slave cylinder, through that newly drilled hole, to atmosphere.

[1FSTRK]

Ron, I believe the primary vents directly to the slave cylinder cavity then out the drilled hole to the side cover.

Brian

Yes, I understand that and that's fine. It's with the addition of this seal, primary venting is stopped, assuming the seal is actually sealing.
Ron

We are either both right or both missing the same thing on this one.
Once that seal is in the nut and the pushrod is installed, the primary is sealed. You can vent the slave cavity all you want.