M8 trans fluid leaking in primary

[Billy]

I'm mot sure how this is suppose to eliminate the transfer, guy brought it to me to install. Looks like 3/8 CRS tapered on the ends then cut flat

Anyone have any experience with this? Thoughts?

Sorry , couldn't resist. I'm sure increasing the space around the tube will reduce flow.
Ron

Ron, don't feel bad, I don't get it either!

Yeah, I don't get it either. It's easy enough to try, I'll take a small leap of faith (from the bottom step) and give it a shot.

[HogMike]

It seems my 2017 cvo limited is showing the same signs.
In less that 1000 miles the level went from the full mark to not showing on the dipstick.

I am confused as what the dealer is telling me verses the TA0022 bulletin:

2014-2016 shows transfer can be 5oz or more and to check in 5000 miles
2017 shows transfer should be checked in 1000 miles (no amount given, I'm assuming it's still @ 5oz or more.)
Dealer is instructed by HD to drain and measure both primary AND transmission fluids, refill to proper levels and check in 5000 miles.
Is there a newer TA than the 9-27-2017 one we see?

Anyway, bike goes in next week to get this issue started AND to fix other issues in the works.
Hate to have warranty work done on a new bike constantly.

I'm leery of running my bike for 5000 miles with no fluid showing on the dipstick.

[Maddo Snr]

Just for the Record. I had 10oz transfer that was at 15,000 miles on the odometer.
Last change a month ago at 20,000 on the odometer I only had 3.5 oz transfer.
Only thing I did different is how I shift. Starting out I pull the clutch completely in.
Shifting between gears I only compress the clutch as much as it needs. Most times 1/4 to 1/3 movement of the lever.

I still say it's a pumping action when depressing the clutch....

Correct! This is as obvious as dog-doo Pan. Oil weeps into the S/C cavity and when the clutch is fully depressed the oil is pumped along the actuator shaft orifice by the S/C diaphragm and into the primary.

Oversized actuator shafts simply block this oil transfer ( the only!) passage. I can't see venting the primary as a solution. That would imply that a vacuum is developing in the primary and sucking oil down the actuator orifice, highly unlikely.

I pulled the trap-door cap/slave cylinder mount off my bike today so I can 3D map it and machine a billet version with a larger internal drain from the S/C cavity to the gearbox sump. I reckon this plus a larger gearbox hat vent will cure it.

Blocking the transfer orifice with a larger diameter rod isn't good engineering IMO. I aim to relieve the pressure differential which is causing the issue. Non-hydraulic clutch bikes don't seem to have the issue, that's the clue AFAIAC.

[Oz Dan]

 The Williams fat push rod doesn't block the main shaft......it's got a flat machined surface along its entire length to allow the primary to breath.

.......yet to hear of a single example where this fat rod didn't fix transfer issues.....seems like a winner fix to me.

[Maddo Snr]

The Williams fat push rod doesn't block the main shaft......it's got a flat machined surface along its entire length to allow the primary to breathe.

I was specifically talking about oversized blocker shafts.

The only way the Williams version can be a fix is if the primary is going into vacuum (not saying this isn't so BTW)

If the primary was going into compression it'd put positive pressure on the rod orifice and stop fluid transfer.

As far as the primary 'breathing' up the rod orifice is concerned, that's unrealistic. The orifice comes to a dead-end at the S/C, the only way it can 'breathe' is through the support bearing which has a nylon seal on it from 5/18.

Not saying the product is a dud, but a technical explanation would be nice...

[HogMike]

The Williams fat push rod doesn't block the main shaft......it's got a flat machined surface along its entire length to allow the primary to breathe.

I was specifically talking about oversized blocker shafts.

The only way the Williams version can be a fix is if the primary is going into vacuum (not saying this isn't so BTW)

If the primary was going into compression it'd put positive pressure on the rod orifice and stop fluid transfer.

As far as the primary 'breathing' up the rod orifice is concerned, that's unrealistic. The orifice comes to a dead-end at the S/C, the only way it can 'breathe' is through the support bearing which has a nylon seal on it from 5/18.

Not saying the product is a dud, but a technical explanation would be nice...

Being I'm not that familiar with the newest transmission and primary case, I can't understand how the primary can get in a vacuum and suck oil from the vented trans through the main shaft?
It was my understanding that whatever pressures build in the trans AND the primary due to heat could/would escape through the vent tube. This would indicate no pressure in either case.
What am I missing?

[Maddo Snr]

Being I'm not that familiar with the newest transmission and primary case, I can't understand how the primary can get in a vacuum and suck oil from the vented trans through the main shaft?
It was my understanding that whatever pressures build in the trans AND the primary due to heat could/would escape through the vent tube. This would indicate no pressure in either case.
What am I missing?

Missing nothing Mike IMO. If the primary was developing pressure it'd push air along the pushrod orifice and force oil BACK into the trans. The opposite is happening, ergo, unless the primary vent mod is there to relieve vacuum it can't be doing anything.

I can see how the bigger diameter rods might help. The key IMO is eliminating oil pressure building in the S/C cavity. Pressure causes flow.

[98fxstc]

Did see a post somewhere where the MoCo fix was installation of a primary vent which stopped the transfer.
Does not seem to have been implemented on a large scale.
Likely relieving vacuum in the primary but no-one has ever put a gauge on a vent to check.

[HogMike]

Being I'm not that familiar with the newest transmission and primary case, I can't understand how the primary can get in a vacuum and suck oil from the vented trans through the main shaft?
It was my understanding that whatever pressures build in the trans AND the primary due to heat could/would escape through the vent tube. This would indicate no pressure in either case.
What am I missing?

Missing nothing Mike IMO. If the primary was developing pressure it'd push air along the pushrod orifice and force oil BACK into the trans. The opposite is happening, ergo, unless the primary vent mod is there to relieve vacuum it can't be doing anything.

I can see how the bigger diameter rods might help. The key IMO is eliminating oil pressure building in the S/C cavity. Pressure causes flow.

Seeing how the primary AND transmission have equal pressure (read:zero) as they share a vent to atmosphere, I would tend to believe the problem would be the slave "pumping" oil into the primary. There does not seem to be an issue with the cable clutch bikes. That is assuming that the main shaft, release rod is of similar design .
Still can't understand how the primary goes into a vacuum state while running??

[rigidthumper]

Here is how HD has addressed it ( from the 2019 parts manuals)

[HogMike]

Just called customer service at HD, they told me to have the local dealer call and use my reference # to get some answers.
Evidently HD techs will not talk to customers directly.

[rbabos]

Being I'm not that familiar with the newest transmission and primary case, I can't understand how the primary can get in a vacuum and suck oil from the vented trans through the main shaft?
It was my understanding that whatever pressures build in the trans AND the primary due to heat could/would escape through the vent tube. This would indicate no pressure in either case.
What am I missing?

Missing nothing Mike IMO. If the primary was developing pressure it'd push air along the pushrod orifice and force oil BACK into the trans. The opposite is happening, ergo, unless the primary vent mod is there to relieve vacuum it can't be doing anything.

I can see how the bigger diameter rods might help. The key IMO is eliminating oil pressure building in the S/C cavity. Pressure causes flow.

Seeing how the primary AND transmission have equal pressure (read:zero) as they share a vent to atmosphere, I would tend to believe the problem would be the slave "pumping" oil into the primary. There does not seem to be an issue with the cable clutch bikes. That is assuming that the main shaft, release rod is of similar design .
Still can't understand how the primary goes into a vacuum state while running??

It shouldn't. During warmup it will vent any increase in pressure from expansion through the pushrod hole and out the trans vent. During cool down the volume of air in the primary will try to contract, again letting air in from the trans vent to stabilize back to normal. If the space between the pushrod and mainshaft hole is blocked with oil, it will pull a small amount oil with it until free air exhange takes over. It will be a small amount, nowhere enough to explain the amounts posted here. So it's back to too much oil gathering around the end of the mainshaft hole for one and pumping action form the slave moving it along over to the primary. Now, if this transfer is happening without a whole lot of shifting going on, the bore machining process inside the shaft might have left a built in directional screw on the wall, constantly trying to move oil toward the primary. If oil is present at the opening, it will constantly move it along in that direction. Glad I don't have any of these issues being wet sump and integrated trans. Then again, done right, the M8s shouldn't have these issues either.
Ron

[Maddo Snr]

Today I machined a prototype s/c housing much like the older CVO housings without an enclosed void around the end of the gearbox shaft.

I also vented the face of the diaphragm housing into the gearbox. Clutch pull is marginally different, I'll put 1000 miles and some dyno time on the mod and report back.

[HogMike]

Update: problem solved!!!

Just kidding, after calling my local dealer, the process is to get the bike in (when they have a mechanic available), drain and measure fluids from both primary and trans, fill both holes to "spec", have me ride the bike for 5000 miles, bring bike back to have them drain and measure fluids again.
If there is a change of 6oz or more, they proceed to call HD to schedule a factory rep to follow up.
We'll see how far the bike goes with just a little trans fluid,

That BMW I've been looking at is getting closer to replacing the cvo, cheaper also.

To get that mileage, I'll have to do a road trip for a few days!
Doesn't seem to me there's any urgency to fix this issue, maybe there IS no issue?

Thanks Ron for filling in some of the details on the operation of the slave to pushrod design. Still not sure why there could be a vacuum with vent clear, etc.

[rbabos]

Update: problem solved!!!

Just kidding, after calling my local dealer, the process is to get the bike in (when they have a mechanic available), drain and measure fluids from both primary and trans, fill both holes to "spec", have me ride the bike for 5000 miles, bring bike back to have them drain and measure fluids again.
If there is a change of 6oz or more, they proceed to call HD to schedule a factory rep to follow up.
We'll see how far the bike goes with just a little trans fluid,

That BMW I've been looking at is getting closer to replacing the cvo, cheaper also.

To get that mileage, I'll have to do a road trip for a few days!
Doesn't seem to me there's any urgency to fix this issue, maybe there IS no issue?

Thanks Ron for filling in some of the details on the operation of the slave to pushrod design. Still not sure why there could be a vacuum with vent clear, etc.

There won't be any measurable vacuum. It will vent from the trans making it impossible as long as the trans vent  is clear. Think of the expansion from heat or cooling down as more of an air exchange. It happens so slowly, there would be no readings with a gauge hooked up. It amazes me how this cluster fk can go on so long with the company. Sumping too. Almost like they are purposely trying to weasel out of looking after their customers. Wouldn't be the first time. Cranks and compensators as previous examples.
Ron

[Hossamania]

But they finally fixed the compensator problem all on their own, so I have faith that they will solve these problems on their own and without an outcry from dissatisfied customers...

[rbabos]

But they finally fixed the compensator problem all on their own, so I have faith that they will solve these problems on their own and without an outcry from dissatisfied customers...

No comment.
Ron

[hd06]

  Venting the primary and problem solves the problem. [attach=0]  [attach=1]  [attach=2]   

[hd06]

  This is where the vent was put. 

[HogMike]

Was this a mod done by Harley?

[hd06]

 Yes, Harley Rep. at a bike rally, I gave him my reference number he looked it up 13 times it's been in the shop for transfer problems. He took it in to dealer shop and put it on. He said he's had 100 % success. Problem solved no fix it kits or odd shaped clutch push rods. It didn't cost my a dime. This the only problem I've had on this bike 9/23/16 was the first noted problem.

[HogMike]

I have my ref # and have to go through the "official procedure " according to the dealer.
I still can't believe that this solves the problem but if that works, I'll be glad to put this behind me.

Did you get any information as why your bike was having this issue to begin with?

It goes against my limited logic how this all works.

[hd06]

 I didn't ask but when you complain to a rep when he is trying to to push a new bike on customers it got some attention. I had this M8 for 2 years and I can't get this transfer problem fixed had the papers in my hand. That got some people attention. I didn't think that would fix it but it did and I'm a happy camper. You could fix it yourself just drill and tap it could try a smaller hose if need be but I'm happy just the way it is.   Good Luck

[HogMike]

Interesting you mentioned fighting this for 2 years, feedback from our SM and GM yesterday is having me rethink waiting up to 10K miles to address this issue.
This comes from the factory rep on a couple of other bikes like mine.

We have lemon laws in this state, my last go around had to deal with the front brakes (safety related).

If there is no resolution in a timely fashion there may be a new bike in my life soon. I'm not willing to have issues when I do my annual long rides.

My patience is wearing thin.

[hd06]

     If I knew this would fix my bike I would have done it the first time it transferred. I would put a smaller vent tube on it, May do that later but it's fixed.