M8 trans fluid leaking in primary

[rbabos]

Looks like the trans vent is a rubber hose with with a flat rubber piece that lands on the inside of the top cover. Has anyone tried pulling the vent hose out (from the inside of the top cover) and just run it open to see if it makes a difference. Maybe the flimsy piece of rubber hose is heating up and collapsing.

If the trans isn't venting then neither is the primary. They would cancel each other out for fluid transfer. I'm not positive but the primary would be venting before the gearbox since it would heat the air up first inside and it's volume is greater. In either case a pin hole would be more then enough since air transfer is really slow relative to hot cold up and down time frames.
Ron
Ron

[HV]

UPDATE ...Because we found one doing this we called the Factory ..they Have NOT Had a lot of reports of this and have NOT Replaced any Transmissions due to it ....so who ever told you different is feeding someone bad information ..I Tend to believe a Factory REP ..sitting in a Chair at the Factory


We have been requested to do a DYE Test to see if in fact the Tranny Fluid is migrating to the Primary Side ...

[rbabos]

UPDATE ...Because we found one doing this we called the Factory ..they Have NOT Had a lot of reports of this and have NOT Replaced any Transmissions due to it ....so who ever told you different is feeding someone bad information ..I Tend to believe a Factory REP ..sitting in a Chair at the Factory


We have been requested to do a DYE Test to see if in fact the Tranny Fluid is migrating to the Primary Side ...

I think that's been proven many times now.
Ron

[PoorUB]

UPDATE ...Because we found one doing this we called the Factory ..they Have NOT Had a lot of reports of this and have NOT Replaced any Transmissions due to it ....so who ever told you different is feeding someone bad information ..I Tend to believe a Factory REP ..sitting in a Chair at the Factory


We have been requested to do a DYE Test to see if in fact the Tranny Fluid is migrating to the Primary Side ...

I think that's been proven many times now.
Ron

Engineering bureaucracy at it's finest! One hole is going down, the other is going up, interconnected by one passage, but we still need proof!

[HV]

Bean counters want the Facts..   only other place it can come from is the Engine ...and that oil isn't going down....not sure what they didnt understand about that       

[harleytuner]

we lost volume in the new case . Funny its not a issue from most dealers ... but hey here is a new trans .. That I like instead of saying well here is a fix and running ti low on fluid caused no extra wear .. That is great to hear

I know 2 dealers that got new transmissions sent to them.  I'm friends with tech's at one of them.  I'll see if he can tell Amy difference in the cases

[borrec]

UPDATE ...Because we found one doing this we called the Factory ..they Have NOT Had a lot of reports of this and have NOT Replaced any Transmissions due to it ....so who ever told you different is feeding someone bad information ..I Tend to believe a Factory REP ..sitting in a Chair at the Factory


We have been requested to do a DYE Test to see if in fact the Tranny Fluid is migrating to the Primary Side ...

On the other forum at least one dealer did the dye test to prove transfer and MoCo sent them a whole new transmission. Gentleman is waiting to get it installed and see if that cured it. Right hand not talking to left hand?

[HV]

You would think that Tech Support at the Factory would know whats been covered ...we will see that Happens with this case...... Im not a Tech from other sites ...or a guy that knows a guy that talked to a guy etc ...If they cover it Yall will know 

[Bike31]

What else is the factory mouth going to say...Houston we've got a problem (oh, that's another thread already)...and so they don't and likely deal with it on a per case basis.

It's not a problem or design defect until it costs warranty to fix, or creates a road hazard the NHTSA Feds require be taken care of. Two drops of that migrating trans oil on a rear tire and it'd be a recall.

In the meantime HD is dye testing and recapturing allegedly defective transmissions to explore. I wonder if they have run their dyno as well?

[HV]

It would be easy for them to check ......I recently got back from the M8 Factory Engine course ...after building our engines each bike was run on a  Factory Dyno and had to meet a minimum HP Reading for each Tech to pass ......those bikes had loads of runs.. ( 8 Bikes ) each course ....5 or 6 Courses .....looking back.. each bike had the primary covers off ( we had to check end play on cranks etc....) before each bike was run we checked Fluid levels......my bikes Tranny was slightly low ...enough that I had to top it up ...and we had not touched the Trannys 

[Durwood]

UPDATE ...Because we found one doing this we called the Factory ..they Have NOT Had a lot of reports of this and have NOT Replaced any Transmissions due to it ....so who ever told you different is feeding someone bad information ..I Tend to believe a Factory REP ..sitting in a Chair at the Factory


We have been requested to do a DYE Test to see if in fact the Tranny Fluid is migrating to the Primary Side ...

Good info Brian

Here's how my scenario went on my bike, and where we are today.

So that it was documented with HD I went to my local dealer after this thread started and had them put in a warranty claim, the factory rep told us to change the top cover gasket.

After removing the original and seeing that just a swap would not change anything, we decided to modify the new gasket with the 3/16" X 1" slot instead of just the 3/16" hole.

So far I have no transfer, and I have worked it very hard and will continue to do so until we feel sure it is completely cured, and if not we will go back to the drawing board.

You guys feel free to try it, it was easy to do. Here's the original gasket.

[attach=0]

[Durwood]

Here is the modified one.
[attach=0]

[borrec]

UPDATE ...Because we found one doing this we called the Factory ..they Have NOT Had a lot of reports of this and have NOT Replaced any Transmissions due to it ....so who ever told you different is feeding someone bad information ..I Tend to believe a Factory REP ..sitting in a Chair at the Factory


We have been requested to do a DYE Test to see if in fact the Tranny Fluid is migrating to the Primary Side ...

Good info Brian

Here's how my scenario went on my bike, and where we are today.

So that it was documented with HD I went to my local dealer after this thread started and had them put in a warranty claim, the factory rep told us to change the top cover gasket.

After removing the original and seeing that just a swap would not change anything, we decided to modify the new gasket with the 3/16" X 1" slot instead of just the 3/16" hole.

So far I have no transfer, and I have worked it very hard and will continue to do so until we feel sure it is completely cured, and if not we will go back to the drawing board.

You guys feel free to try it, it was easy to do. Here's the original gasket.

[attach=0]

Thank you. People like you and HV are the ones that make forums so useful to the rest of us. 

[blackhillsken]

Durwood, is that a small notch cut into the cover web about an inch down from the top between the main compartment and vent cavity ?

[Durwood]

Durwood, is that a small notch cut into the cover web about an inch down from the top between the main compartment and vent cavity ?

No, the cover is flat, but if you look at the original gasket you will see where the notch is located in the trans case, that small notch and a slot in the lower part of the case is all that feeds the vent cavity.

[blackhillsken]

Thank you for your testing

[Durwood]

Thank you for your testing

You're welcome, I hope if Herko and I don't find the solution, that someone else does.

Here's a view of the M8 trans with the cover removed.
[attach=0]

[Durwood]

Here is a pic of a Twin cam trans with the cover removed, note the two much larger holes that go to vent cavity? No half moon notch or smallish slot like the M8, and also the notice that the TC vent cavity is much larger. I don't know if that has anything to do with it, but I thought it was noteworthy.
[attach=0]  

[103eagle]

Good Info, hope its this simple of a fix.  Durwood, what I assume is you feel it is a venting issue then?  How long have you run the bike with this test gasket?

Thanks

Eagle Out

[Sunny Jim]

Thankyou Darren.

[HV]

We will be testing the "Durwood" Fix as soon as we get another one thats doing this   

[rbabos]

Can't tell from the pics but are all three chambers sharing a common vent. The one closest to the trap looks to have been blocked off with the gasket until the slot was added. Note the notch in the second wall at the top to vent from one to other. One notch in the next top or the modded gasket might cure it if that last chamber wasn't vented. Somewhat unlikely since there should be openings near the bottom of each to allow fluid to find a common level throughout the case, in which case venting should still occur regardless to only having one common hole unless, no vent at top of the trap side and the two other chambers force the oil level higher then normal from the lower transfer area into the trap side section and higher then the opening of the pushrod hole.  So, what's the theory behind what the slotted gasket does?
Ron

[Durwood]

Good Info, hope its this simple of a fix.  Durwood, what I assume is you feel it is a venting issue then?  How long have you run the bike with this test gasket?

Thanks

Eagle Out

Not enough time on it yet to say this is the for sure fix, One vigorous dyno tuning session with over 30 max power runs and a couple hundred miles of very spirited riding. I have another set of mufflers on the way to test, this will add a bunch more max power runs along with the extensive Herko steady state tuning method.

We will be testing the "Durwood" Fix as soon as we get another one thats doing this   

That would be awesome and one of the main reasons I posted the pics. Herko said we need more than one test bike for this.

I can't take any credit as I am not the only one involved here, but thanks Brian. All I want is to get it fixed, and I am not a quitter.

Can't tell from the pics but are all three chambers sharing a common vent. The one closest to the trap looks to have been blocked off with the gasket until the slot was added. Note the notch in the second wall at the top to vent from one to other. One notch in the next top or the modded gasket might cure it if that last chamber wasn't vented. Somewhat unlikely since there should be openings near the bottom of each to allow fluid to find a common level throughout the case, in which case venting should still occur regardless to only having one common hole unless, no vent at top of the trap side and the two other chambers force the oil level higher then normal from the lower transfer area into the trap side section and higher then the opening of the pushrod hole.  So, what's the theory behind what the slotted gasket does?
Ron

Chamber's one and three vent through the half moon notch in the rib between one and two, also the small slot below it.

Chamber three has two passages that vent to the lower "common" part of the trans case, one in the very bottom of that chamber and one towards the top at the rear of it that goes at an angle back towards the rear of the trans.

When the moco suggested changing the gasket, that was when we gave the venting a hard look and this is what we came up with for now.

As I stated earlier, only with more dyno time and hard riding will we know if it is a hit or miss, but at least it can't be said we are not trying, and with more bikes involved the testing will be greatly improved.

[rbabos]

Good Info, hope its this simple of a fix.  Durwood, what I assume is you feel it is a venting issue then?  How long have you run the bike with this test gasket?

Thanks

Eagle Out

Not enough time on it yet to say this is the for sure fix, One vigorous dyno tuning session with over 30 max power runs and a couple hundred miles of very spirited riding. I have another set of mufflers on the way to test, this will add a bunch more max power runs along with the extensive Herko steady state tuning method.

We will be testing the "Durwood" Fix as soon as we get another one thats doing this   

That would be awesome and one of the main reasons I posted the pics. Herko said we need more than one test bike for this.

I can't take any credit as I am not the only one involved here, but thanks Brian. All I want is to get it fixed, and I am not a quitter.

Can't tell from the pics but are all three chambers sharing a common vent. The one closest to the trap looks to have been blocked off with the gasket until the slot was added. Note the notch in the second wall at the top to vent from one to other. One notch in the next top or the modded gasket might cure it if that last chamber wasn't vented. Somewhat unlikely since there should be openings near the bottom of each to allow fluid to find a common level throughout the case, in which case venting should still occur regardless to only having one common hole unless, no vent at top of the trap side and the two other chambers force the oil level higher then normal from the lower transfer area into the trap side section and higher then the opening of the pushrod hole.  So, what's the theory behind what the slotted gasket does?
Ron

Chamber's one and three vent through the half moon notch in the rib between one and two, also the small slot below it.

Chamber three has two passages that vent to the lower "common" part of the trans case, one in the very bottom of that chamber and one towards the top at the rear of it that goes at an angle back towards the rear of the trans.

When the moco suggested changing the gasket, that was when we gave the venting a hard look and this is what we came up with for now.

As I stated earlier, only with more dyno time and hard riding will we know if it is a hit or miss, but at least it can't be said we are not trying, and with more bikes involved the testing will be greatly improved.

Thanks Darren for the detailed layout description.
Ron

[Prostock]

Good stuff Darren

Scot