M8 trans fluid leaking in primary

[rbabos]

Without a vent from the primary isn't there a risk of pushing oil vapor into the starter?   

Is that directed at my post? You would leave enough room between the bushing and the shaft for the primary to vent to the transmission.

Not at all. I have been following this thread after reading the one the link was to in the other forum where they are machining a nut for a pushrod seal. My thought is, if you seal of the only vent (which is through the trans, the next likely route is through the starter armature brg.. I can't imagine that seal is spec;d for that kind of duty but maybe it is.

That pic fooled me to on the sealing part. Lighten up the pic to see the inner part of the seal. It has no contact on the shaft basically so the concerns of venting are none existant since there is no sealing. This is the fix?
Ron

Even if it works, it's to complicated, Harley will never steal it.
I've got a main shaft, push rod and some supplies coming. Oil sling on the push rod and a dam in the hole of the cylinder.

They are waiting for a better option. Larger dia pushrod that only has about .0015-.002 clearance at the two outer ends  (2") of the mainshaft bore and a correct cupped slinger at the trap bearing. The posted modified nut somewhat acts that way but not as good as it could as far as slinging oil goes because it doesn't have the needed vertical surface area. The new pushrod with the reduced clearances at ends and having 1/8" wide x 1/32 deep at 1/8" spaced square grooves machined in it at the first 2" from the slave will also act as a half assed labyrinth seal. Total sealing isn't needed , just a big reduction as well as a slinger for directional control for the oil.
Ron

[14GuineaPig]

I could be wrong but this is what I think the fix is.  The stock setup allows oil to pass into a chamber in the transmission inner side cover where the actuator is mounted.  That oil is then forced thru the inside of the mainshaft when the actuator moves during shifting.  The inside of the mainshaft is where the clutch pushrod runs and also how the primary is vented.
By changing the nut on the end of the mainshaft to a longer nut and then machining one end of that nut round, it allows the nut to sit into a seal.  That seal has been added to the transmission inner side cover.  What it does is seal the chamber that the actuator is mounted to.  Now no oil can enter that chamber around the outside of the mainshaft.  Because the chamber is now sealed, a vent hole has been added that will allow the primary to vent thru the mainshaft as it always did, but now it will vent thru the side cover.

[harley_cruiser]

Without a vent from the primary isn't there a risk of pushing oil vapor into the starter?   

Is that directed at my post? You would leave enough room between the bushing and the shaft for the primary to vent to the transmission.

Not at all. I have been following this thread after reading the one the link was to in the other forum where they are machining a nut for a pushrod seal. My thought is, if you seal of the only vent (which is through the trans, the next likely route is through the starter armature brg.. I can't imagine that seal is spec;d for that kind of duty but maybe it is.

That pic fooled me to on the sealing part. Lighten up the pic to see the inner part of the seal. It has no contact on the shaft basically so the concerns of venting are none existant since there is no sealing. This is the fix?
Ron

Even if it works, it's to complicated, Harley will never steal it.
I've got a main shaft, push rod and some supplies coming. Oil sling on the push rod and a dam in the hole of the cylinder.

They are waiting for a better option. Larger dia pushrod that only has about .0015-.002 clearance at the two outer ends  (2") of the mainshaft bore and a correct cupped slinger at the trap bearing. The posted modified nut somewhat acts that way but not as good as it could as far as slinging oil goes because it doesn't have the needed vertical surface area. The new pushrod with the reduced clearances at ends and having 1/8" wide x 1/32 deep at 1/8" spaced square grooves machined in it at the first 2" from the slave will also act as a half assed labyrinth seal. Total sealing isn't needed , just a big reduction as well as a slinger for directional control for the oil.
Ron

That is interesting, I was under the impression that there was not enough room for a slinger. Not only do you need room for it but for it to move back and forth. If that will keep the oil out of the tunnel, however any oil that makes it way into the tunnel is pushed by centrifugal force against the wall. If you put a drop of oil an inch inside the tunnel half will be forced in half out. Hopefully the bigger end closer tolerance will keep the oil out.

[HD/Wrench]

the ' fix" well  high speed ( rpm) tends to drastically increase transfer .. So if a given bike is babied along it may be " cured"  however is it really   I tune them and ask the customer  if I speak with them. I have had them tell me no its fine. I check the level,,,it  is in the proper range. I run it on the drum and the bike that had no issue no has one.. Must be the dyno monster put a hex on it .. 


Tongue in cheek     so operation of given bike is going to be part of the test and not just a quick rip through the gears.  Go out put 250 miles on the bike up and down through the gears having a bit of fun with it , some high rpm pulls and then see if it no longer has an issue.

[koko3052]

I'm kind of with you there & the "some do..some don't" mantra. They are all made by the same manufacturer, using the same parts and probably all from the same suppliers.

[hd06]

 What if you have a lift handed thread on the shaft, it will force the oil back to the trans.

[PoorUB]

What if you have a lift handed thread on the shaft, it will force the oil back to the trans.

Left hand thread where?

[PC_Hater]

A left hand scroll on the end of the shaft that sits toward the primary. In theory it throws any oil back out into the transmission. As we can tell from the very many vintage bikes and cars that used the same method before they had decent oil seals - it sort of works, but only sort of. They all fitted proper oil seals in their later designs.

[PoorUB]

Why wouldn't the push rod spin the same RPM as the main shaft most of the time?

[harley_cruiser]

What if you have a lift handed thread on the shaft, it will force the oil back to the trans.

There is not enough room, hole is .376 push rod I'd .312. Plus both the rod and the shaft hole are rotating this would force the oil onto the tunnel wall and the threads would have to be a precise fit. The hole/tunnel is not concentric with the shaft.

[PC_Hater]

What if you have a lift handed thread on the shaft, it will force the oil back to the trans.

There is not enough room, hole is .376 push rod I'd .312. Plus both the rod and the shaft hole are rotating this would force the oil onto the tunnel wall and the threads would have to be a precise fit. The hole/tunnel is not concentric with the shaft.

No. The old engineers knew that a precise fit was not needed. That left-hand scroll really does send the oil back where it came from. In this case back into the transmission. It doesn't work at all to modern standards, but in 1920 or 1942 or even 1960 it worked to everybodys satisfaction. They expected some leakage. As long as it wasn't an almighty flood of oil it was OK.

Is that particular band-aid good enough in this case? Dunno. Somebody would have to try it and see.

[PoorUB]

No. The old engineers knew that a precise fit was not needed. That left-hand scroll really does send the oil back where it came from. In this case back into the transmission. It doesn't work at all to modern standards, but in 1920 or 1942 or even 1960 it worked to everybodys satisfaction. They expected some leakage. As long as it wasn't an almighty flood of oil it was OK.

Is that particular band-aid good enough in this case? Dunno. Somebody would have to try it and see.

Again, it only works with the two shafts turning different speeds. I would bet that about 95%+ of the time the push rod spins the same speed as the main shaft, why wouldn't it?!

[rbabos]

What if you have a lift handed thread on the shaft, it will force the oil back to the trans.

There is not enough room, hole is .376 push rod I'd .312. Plus both the rod and the shaft hole are rotating this would force the oil onto the tunnel wall and the threads would have to be a precise fit. The hole/tunnel is not concentric with the shaft.

Just to clarify. Is it hole .376 and the pr od .312?
Ron

[harley_cruiser]

What if you have a lift handed thread on the shaft, it will force the oil back to the trans.

There is not enough room, hole is .376 push rod I'd .312. Plus both the rod and the shaft hole are rotating this would force the oil onto the tunnel wall and the threads would have to be a precise fit. The hole/tunnel is not concentric with the shaft.

Just to clarify. Is it hole .376 and the pr od .312?
Ron

Yes Steve Cole said  0.376" - 0.382 and that the hole/tunnel is not concentric, push rod, .312.

[rbabos]

What if you have a lift handed thread on the shaft, it will force the oil back to the trans.

There is not enough room, hole is .376 push rod I'd .312. Plus both the rod and the shaft hole are rotating this would force the oil onto the tunnel wall and the threads would have to be a precise fit. The hole/tunnel is not concentric with the shaft.

Just to clarify. Is it hole .376 and the pr od .312?
Ron

Yes Steve Cole said  0.376" - 0.382 and that the hole/tunnel is not concentric, push rod, .312.

No wonder the damn thing leaks then . 
Ron

[PC_Hater]

No. The old engineers knew that a precise fit was not needed. That left-hand scroll really does send the oil back where it came from. In this case back into the transmission. It doesn't work at all to modern standards, but in 1920 or 1942 or even 1960 it worked to everybodys satisfaction. They expected some leakage. As long as it wasn't an almighty flood of oil it was OK.

Is that particular band-aid good enough in this case? Dunno. Somebody would have to try it and see.

Again, it only works with the two shafts turning different speeds. I would bet that about 95%+ of the time the push rod spins the same speed as the main shaft, why wouldn't it?!

No.
Now the question becomes: does the clutch pushrod rotate while riding along?
If it does, a left-hand scroll will move some oil back into the transmission.
It it doesn't, well, a left hand scroll will do nothing at all.

[rbabos]

No. The old engineers knew that a precise fit was not needed. That left-hand scroll really does send the oil back where it came from. In this case back into the transmission. It doesn't work at all to modern standards, but in 1920 or 1942 or even 1960 it worked to everybodys satisfaction. They expected some leakage. As long as it wasn't an almighty flood of oil it was OK.

Is that particular band-aid good enough in this case? Dunno. Somebody would have to try it and see.

Again, it only works with the two shafts turning different speeds. I would bet that about 95%+ of the time the push rod spins the same speed as the main shaft, why wouldn't it?!

No.
Now the question becomes: does the clutch pushrod rotate while riding along?
If it does, a left-hand scroll will move some oil back into the transmission.
It it doesn't, well, a left hand scroll will do nothing at all.

Key is to reduce clearance between the two. There's not enough predictable rotation difference between the two for a screw effect to work, the way I see it. Reducing the gap has obvious effects.
Ron

[hd06]

 Is the tunnel have a smooth ID, If so could you use a O ring, Just a thought.

[PC_Hater]

No. The old engineers knew that a precise fit was not needed. That left-hand scroll really does send the oil back where it came from. In this case back into the transmission. It doesn't work at all to modern standards, but in 1920 or 1942 or even 1960 it worked to everybodys satisfaction. They expected some leakage. As long as it wasn't an almighty flood of oil it was OK.

Is that particular band-aid good enough in this case? Dunno. Somebody would have to try it and see.

Again, it only works with the two shafts turning different speeds. I would bet that about 95%+ of the time the push rod spins the same speed as the main shaft, why wouldn't it?!

No.
Now the question becomes: does the clutch pushrod rotate while riding along?
If it does, a left-hand scroll will move some oil back into the transmission.
It it doesn't, well, a left hand scroll will do nothing at all.

Key is to reduce clearance between the two. There's not enough predictable rotation difference between the two for a screw effect to work, the way I see it. Reducing the gap has obvious effects.
Ron

No No and thrice No! (only the english will get that...)
Owning a V-Rod has made you forget how things were done a 100 years ago.
The speed difference counts for nothing. The clearances count for almost nothing. Tight is good, loose will work.
What matters is: Does that clutch pushrod rotate when the bike is moving down the road?
If it does, a left hand scroll on that clutch pushrod WILL move oil back into the transmission. Not all of it, but some. And if some is good enough it will work.
Really. Talk to anyone you know with a proper old car or bike. They all used the left hand scroll trick instead of proper oil seals. Back then they either cost too much or didn't exist.

[rbabos]

No. The old engineers knew that a precise fit was not needed. That left-hand scroll really does send the oil back where it came from. In this case back into the transmission. It doesn't work at all to modern standards, but in 1920 or 1942 or even 1960 it worked to everybodys satisfaction. They expected some leakage. As long as it wasn't an almighty flood of oil it was OK.

Is that particular band-aid good enough in this case? Dunno. Somebody would have to try it and see.

Again, it only works with the two shafts turning different speeds. I would bet that about 95%+ of the time the push rod spins the same speed as the main shaft, why wouldn't it?!

No.
Now the question becomes: does the clutch pushrod rotate while riding along?
If it does, a left-hand scroll will move some oil back into the transmission.
It it doesn't, well, a left hand scroll will do nothing at all.

Key is to reduce clearance between the two. There's not enough predictable rotation difference between the two for a screw effect to work, the way I see it. Reducing the gap has obvious effects.
Ron

No No and thrice No! (only the english will get that...)
Owning a V-Rod has made you forget how things were done a 100 years ago.
The speed difference counts for nothing. The clearances count for almost nothing. Tight is good, loose will work.
What matters is: Does that clutch pushrod rotate when the bike is moving down the road?
If it does, a left hand scroll on that clutch pushrod WILL move oil back into the transmission. Not all of it, but some. And if some is good enough it will work.
Really. Talk to anyone you know with a proper old car or bike. They all used the left hand scroll trick instead of proper oil seals. Back then they either cost too much or didn't exist.

No, I haven't,  didn't forget cruditity, and being 65, even though not involved with Farmers Insurance, I've seen a thing or two.  Pushrod in this case moves with the main shaft as in the same rpm. Any screw effect sealing, the objects move at different speeds or one is stationary and the other rotates. Works quite well, actually.  Clearances count for everything in this case and a good first step to reduce transfer to an acceptable level . I also spent a week on Amarilla Discovery 2, mostly Brits so I'm almost dialed into your language too. Only one week. Next time maybe a fortnight.
Ron

[PoorUB]

Again, it only works with the two shafts turning different speeds. I would bet that about 95%+ of the time the push rod spins the same speed as the main shaft, why wouldn't it?!

No.
Now the question becomes: does the clutch pushrod rotate while riding along?
If it does, a left-hand scroll will move some oil back into the transmission.
It it doesn't, well, a left hand scroll will do nothing at all.

Again, I ask, why wouldn't the push rod spin along with the main shaft? If it spins slower than the main shaft why isn't there a bearing for the push rod at the clutch end? There is no reason for it not to spin the same speed. There is a reasonable amount of friction along the length, might just be lube, but the lube wants to drag it along, plus the rod has little inertia to over come so it just spins along. There is nothing to stop it from spinning with the main shaft!

[VDeuce]

No. The old engineers knew that a precise fit was not needed. That left-hand scroll really does send the oil back where it came from. In this case back into the transmission. It doesn't work at all to modern standards, but in 1920 or 1942 or even 1960 it worked to everybodys satisfaction. They expected some leakage. As long as it wasn't an almighty flood of oil it was OK.

Is that particular band-aid good enough in this case? Dunno. Somebody would have to try it and see.

Again, it only works with the two shafts turning different speeds. I would bet that about 95%+ of the time the push rod spins the same speed as the main shaft, why wouldn't it?!

No.
Now the question becomes: does the clutch pushrod rotate while riding along?
If it does, a left-hand scroll will move some oil back into the transmission.
It it doesn't, well, a left hand scroll will do nothing at all.

Key is to reduce clearance between the two. There's not enough predictable rotation difference between the two for a screw effect to work, the way I see it. Reducing the gap has obvious effects.
Ron

This is why I have seen some suggest trying the '14 CVO 3-piece pushrod that is thicker in diameter. I have no other information, but if you lookup the parts fiche at Ronnies, you do see the different part numbers for a '14 CVO.

[hd06]

 OK what if we tap out a left handed thread on the main shaft, centrifugal force may keep the fluid in the trans. Maybe

[koko3052]

OK what if we tap out a left handed thread on the main shaft, centrifugal force may keep the fluid in the trans. Maybe

THAT would be the place to start.... because the oil is flung to the inside wall!

[harley_cruiser]

OK what if we tap out a left handed thread on the main shaft, centrifugal force may keep the fluid in the trans. Maybe

THAT would be the place to start.... because the oil is flung to the inside wall!

That is the secret, the centrifugal force is what is making the oil run down the tunnel in the shaft in the first place. The way to stop is is to use the centrifugal force and have a dam inside the tunnel that the oil has to climb and the centrifugal force will keep it from doing that.
I've modified my design slightly but the concept is the same.



The insert is tapered so that it forms a dam, it will have enough clearance so that the push rod will go through and still have enough room for the primary to vent.  Also enough room so that the non concentric tunnel will not be a problem. The oil will not climb up that taper the centrifugal force will force it back towards the opening and be flung out of the end.
There will also be a oil slinger on the push rod so that the oil can not walk down into the tunnel but be flung before getting there, it wont be very large but won't have to be.
I will have prototypes ready in the next day or so and will be looking for volunteers to test them.