M8 trans fluid leaking in primary

[hdrider]

When I talked to Baker we didn't get into the inherent mechanical advantage differences of the 1.5 inch vs 1 inch piston.  Maybe someone could check if the Harley stock piston is actually 1 inch -- the Baker website info simply says its compatible with the stock H-D or 11/16 Master Cylinder.  What the Baker guy was trying to explain was that the stock HD piston was so close in size to the opposing nut size, that tranny fluid had a hard time getting squished out of the gap between the piston and nut, but with the larger bore Baker piston the fluid could escape around the sides of the nut.
I'm just the messenger on this -- the Baker guy seemed to be a true believer in this solution.  I think somebody with the issue needs to try this and report back if it's really a cure or not.
I've been holding off buying an M8 just because of this problem. so I don't have an M8 to experiment on, otherwise I'd gladly do it myself.

[CarlosGGodfrog]

I have a 2000 Heritage Springer that I converted to hydraulic clutch using H-D side cover a few years ago (4). I had to replace the piston because of a bad o-ring on the piston. I just measured it -> 1.595 inches, and I have never had a fluid transfer problem.
Do the TC 5-speed and 6-speeds (TC and M8) use the same bolt pattern on the side cover ?

[PoorUB]

This is what's printed on the Baker website about the Hydraulic Side Cover:

Taking design cues from our ever increasing product family known as Function Formed, we have wrapped the outer design around the functional components found inside. No garnish, or decorations, just the meat and potatoes to make this side cover look as good as it functions.

Features

FF aesthetics milled out of 6061-T6 with chrome finish.
Low profile external features for maximum exhaust clearance.
12 Point stainless steel ARP bolts and gasket included.
1.5″ diameter piston included.
Compatible with H-D or 11/16″ hydraulic master cylinders.
Fitment: BAKER DD7, BAKER GrudgeBox, Stock 6-Speed

PN DD7-106C-Kit (For Chrome)

PN DD7-106B-Kit (For Hog Black)

Screaming Eagle bikes must retrofit to the cable style center push rod system; 3pc system.

Sure, but what is the stock diameter?

[Mark P]

When I talked to Baker we didn't get into the inherent mechanical advantage differences of the 1.5 inch vs 1 inch piston.  Maybe someone could check if the Harley stock piston is actually 1 inch -- the Baker website info simply says its compatible with the stock H-D or 11/16 Master Cylinder.  What the Baker guy was trying to explain was that the stock HD piston was so close in size to the opposing nut size, that tranny fluid had a hard time getting squished out of the gap between the piston and nut, but with the larger bore Baker piston the fluid could escape around the sides of the nut.
I'm just the messenger on this -- the Baker guy seemed to be a true believer in this solution.  I think somebody with the issue needs to try this and report back if it's really a cure or not.
I've been holding off buying an M8 just because of this problem. so I don't have an M8 to experiment on, otherwise I'd gladly do it myself.

I have a guy bringing his M8 over to my shop this weekend and I'm going to try and install one of our covers. I let you know how it works.

[rbabos]

When I talked to Baker we didn't get into the inherent mechanical advantage differences of the 1.5 inch vs 1 inch piston.  Maybe someone could check if the Harley stock piston is actually 1 inch -- the Baker website info simply says its compatible with the stock H-D or 11/16 Master Cylinder.  What the Baker guy was trying to explain was that the stock HD piston was so close in size to the opposing nut size, that tranny fluid had a hard time getting squished out of the gap between the piston and nut, but with the larger bore Baker piston the fluid could escape around the sides of the nut.
I'm just the messenger on this -- the Baker guy seemed to be a true believer in this solution.  I think somebody with the issue needs to try this and report back if it's really a cure or not.
I've been holding off buying an M8 just because of this problem. so I don't have an M8 to experiment on, otherwise I'd gladly do it myself.

I have a guy bringing his M8 over to my shop this weekend and I'm going to try and install one of our covers. I let you know how it works.

I would hope it already works or why would you be selling it? A technical explanation of how it works would suffice. Not like anything can be kept a secret for long.
Ron

[Jobie]

I just got off the phone with Baker and they told me that they don't have a tranny cover that will fit the M8.  I asked them what they thought was causing the issue with oil transfer.  They stated that Harley has made the tranny cover narrower and that it doesn't leave enough room for the oil at that end of the tranny and every time you shift it lets a little oil run over into the primary through the output shaft.  Also Baker doesn't think venting the primary case would help because venting isn't the issue in their opinion.  My bike is ready for pick up at the dealer for a 5 thousand mile oil monitoring.  We all know what that outcome will be, yep you are getting oil transfer.  The problem with that for me is that if a person was trying to give the bike back to Harley under the lemon law you would have to do this 3 to 4 times in one year to qualify for the lemon law. [ if your state has one ] Think about it, that would be 15 to 20 thousand miles in monitoring in one year, plus bet ya HD will only be willing to do the monitoring once.  Just like Harley not to fix the problem but call it normal.   Now for the crying....I have been riding Harleys for 53 years and every NEW HD I bought had issues that they would not address.  If they don't change the tolerances [ think crank runout to leak down test ] they call it normal.  Baker feels that the only fix would be a different tranny cover or maybe some machine work on the original cover. [ needs to be tested ] Never had this issue till the cover got re-design for the 17 - 18 M8's.  I don't think that Harley is going to hand out that many new, re-designed covers to fix the problem but I bet they will be on all the 2019's. Harley hopes that most people just puts gas in it and ride it to the dealer for oil changes.  I'm almost done with HD's problems and lack of fixes and their complacency with some issues.  My new name will be TRADER on a new Wing if this doesn't get fixed. Say what you want, I'm not a poser wearing a Harley shirt. The shirts will go with the bike.  I just want to ride without issues.

[ckwizard]

I just got off the phone with Baker and they told me that they don't have a tranny cover that will fit the M8.  I asked them what they thought was causing the issue with oil transfer.  They stated that Harley has made the tranny cover narrower and that it doesn't leave enough room for the oil at that end of the tranny and every time you shift it lets a little oil run over into the primary through the output shaft.  Also Baker doesn't think venting the primary case would help because venting isn't the issue in their opinion.  My bike is ready for pick up at the dealer for a 5 thousand mile oil monitoring.  We all know what that outcome will be, yep you are getting oil transfer.  The problem with that for me is that if a person was trying to give the bike back to Harley under the lemon law you would have to do this 3 to 4 times in one year to qualify for the lemon law. [ if your state has one ] Think about it, that would be 15 to 20 thousand miles in monitoring in one year, plus bet ya HD will only be willing to do the monitoring once.  Just like Harley not to fix the problem but call it normal.   Now for the crying....I have been riding Harleys for 53 years and every NEW HD I bought had issues that they would not address.  If they don't change the tolerances [ think crank runout to leak down test ] they call it normal.  Baker feels that the only fix would be a different tranny cover or maybe some machine work on the original cover. [ needs to be tested ] Never had this issue till the cover got re-design for the 17 - 18 M8's.  I don't think that Harley is going to hand out that many new, re-designed covers to fix the problem but I bet they will be on all the 2019's. Harley hopes that most people just puts gas in it and ride it to the dealer for oil changes.  I'm almost done with HD's problems and lack of fixes and their complacency with some issues.  My new name will be TRADER on a new Wing if this doesn't get fixed. Say what you want, I'm not a poser wearing a Harley shirt. The shirts will go with the bike.  I just want to ride without issues.

Don't get to exited,
The wings have their issues as well with ghost shifting, blown transmissions, bad pulse generators stranding you in the middle of nowhere and oh yeah very very limited accessories to chose from.
I also own an F6B and while the GL1800 engine is awesome it sure as hell isn't trouble free.
Plus I am not convinced this so called oil transfer issue is a problem at all because the only place I ever here about it is right here.
Cheers

[PoorUB]

Only here? You must not read the other Harley forums. They all are talking about it!

[Hunter14]

Only here? You must not read the other Harley forums. They all are talking about it!

Yep.....Its on every forum , And most dealers will not tell you that they have at least 3 or 4 M8's with the trans to primary transfer at their dealership.....And I'm willing to bet quite a few owners who don't  ride more than a thousand miles or so in a year even know their M8's have that problem ......
Till the warranty is up....

[14GuineaPig]

Plus I am not convinced this so called oil transfer issue is a problem at all because the only place I ever here about it is right here.
Cheers

I guess the fact that HD put out Tech Article "Tech Article TA0022: Transmission to Primary Oil Transfer" means nothing because you haven't experienced the problem.  HD is not very forthcoming when admitting problems with their bikes so I have to believe that for HD to issue a Tech Article, the problem does exist and it exists on more than just a handful of bikes.  Keep living in denial

[hdrider]

I just got off the phone with Baker and they told me that they don't have a tranny cover that will fit the M8.  I asked them what they thought was causing the issue with oil transfer.  They stated that Harley has made the tranny cover narrower and that it doesn't leave enough room for the oil at that end of the tranny and every time you shift it lets a little oil run over into the primary through the output shaft.  Also Baker doesn't think venting the primary case would help because venting isn't the issue in their opinion.  My bike is ready for pick up at the dealer for a 5 thousand mile oil monitoring.  We all know what that outcome will be, yep you are getting oil transfer.  The problem with that for me is that if a person was trying to give the bike back to Harley under the lemon law you would have to do this 3 to 4 times in one year to qualify for the lemon law. [ if your state has one ] Think about it, that would be 15 to 20 thousand miles in monitoring in one year, plus bet ya HD will only be willing to do the monitoring once.  Just like Harley not to fix the problem but call it normal.   Now for the crying....I have been riding Harleys for 53 years and every NEW HD I bought had issues that they would not address.  If they don't change the tolerances [ think crank runout to leak down test ] they call it normal.  Baker feels that the only fix would be a different tranny cover or maybe some machine work on the original cover. [ needs to be tested ] Never had this issue till the cover got re-design for the 17 - 18 M8's.  I don't think that Harley is going to hand out that many new, re-designed covers to fix the problem but I bet they will be on all the 2019's. Harley hopes that most people just puts gas in it and ride it to the dealer for oil changes.  I'm almost done with HD's problems and lack of fixes and their complacency with some issues.  My new name will be TRADER on a new Wing if this doesn't get fixed. Say what you want, I'm not a poser wearing a Harley shirt. The shirts will go with the bike.  I just want to ride without issues.

After all the comments after my original post about the Baker fix for the fluid transfer, I went back to the Baker Vendor Display at Black Hills Harley in Rapid City and had a detailed discussion with 2 additional Baker Technicians and I believe I've finally gotten some answers.  Apparently the original technician I had talked to wasn't as clear in his explanation or he may have left some details out.

What I found out today is:

1. Baker firmly believes that their Hydraulic Side Cover design solves the M8 fluid transfer problem

2. The M8 Hydraulic Side Cover is in Production, but not available to order yet.  The covers are in final machining and still need to be chromed.  Expect them to be available to order in about a month.

3. The specs on the Baker website for the 06-17 Hydraulic Cover are for the Twin Cam Cover -- not the M8.

4.  The Piston size in the Stock H-D M8 and new M8 Baker Hydraulic Cover are the same size and slightly smaller than on the Twin Cam (don't know why H-D reduced the piston size for the M8).

5.  The big difference between the H-D cover and the Baker cover is that the H-D cover has a piston stop as part of the casting.  The stop limits the piston travel so it can't be pushed out of the bore, however this stop extends beyond the piston and literally surrounds the nut on the tranny door -- this creates a pocket that limits the movement of tranny fluid which gets pressurized and pushed past the clutch rod every time the clutch is actuated.  The Baker design doesn't have a piston stop --  the piston could theoretically be pushed out of the bore, but in reality is limited by the clutch rod travel, and finally it would hit the tranny nut before leaving the bore.  In other words the Baker design leaves the Tranny nut completely unshrouded.  At least thats the way it was explained to me by the latest Baker Technician and a bit different than my original understanding (and posting).

[Nastytls]

I just got off the phone with Baker and they told me that they don't have a tranny cover that will fit the M8.  I asked them what they thought was causing the issue with oil transfer.  They stated that Harley has made the tranny cover narrower and that it doesn't leave enough room for the oil at that end of the tranny and every time you shift it lets a little oil run over into the primary through the output shaft.  Also Baker doesn't think venting the primary case would help because venting isn't the issue in their opinion.  My bike is ready for pick up at the dealer for a 5 thousand mile oil monitoring.  We all know what that outcome will be, yep you are getting oil transfer.  The problem with that for me is that if a person was trying to give the bike back to Harley under the lemon law you would have to do this 3 to 4 times in one year to qualify for the lemon law. [ if your state has one ] Think about it, that would be 15 to 20 thousand miles in monitoring in one year, plus bet ya HD will only be willing to do the monitoring once.  Just like Harley not to fix the problem but call it normal.   Now for the crying....I have been riding Harleys for 53 years and every NEW HD I bought had issues that they would not address.  If they don't change the tolerances [ think crank runout to leak down test ] they call it normal.  Baker feels that the only fix would be a different tranny cover or maybe some machine work on the original cover. [ needs to be tested ] Never had this issue till the cover got re-design for the 17 - 18 M8's.  I don't think that Harley is going to hand out that many new, re-designed covers to fix the problem but I bet they will be on all the 2019's. Harley hopes that most people just puts gas in it and ride it to the dealer for oil changes.  I'm almost done with HD's problems and lack of fixes and their complacency with some issues.  My new name will be TRADER on a new Wing if this doesn't get fixed. Say what you want, I'm not a poser wearing a Harley shirt. The shirts will go with the bike.  I just want to ride without issues.

Don't get to exited,
The wings have their issues as well with ghost shifting, blown transmissions, bad pulse generators stranding you in the middle of nowhere and oh yeah very very limited accessories to chose from.
I also own an F6B and while the GL1800 engine is awesome it sure as hell isn't trouble free.
Plus I am not convinced this so called oil transfer issue is a problem at all because the only place I ever here about it is right here.
Cheers

When you make comments without knowing anything about the subject that you're commenting on, you look like a fool.  There are countless posts on multiple forums spelling out this issue. HD issued a Tech bulletin about it. HD has issued "fixes" that didn't fix the problem. MY BIKE DOES IT. So it's not internet hysteria, it's a very real and significant problem with their design. "Don't get too excited"? This design is two yrs old and Harley has shown that they have no clue how to stop it other than to keep draining the primary and re-filling the fluids.

[ckwizard]

i just don't see why I should care if a little oil transfer is goin on.
I have never heard of a trans or primary blowing up from the oils co-mingling together nor has it happened to anyone that I ride with.
Been riding these beasts for over 40 years and average 10-15k a year so i'm no newby but if ya'll want to throw good money at this be my guest.
Be safe

[rbabos]

i just don't see why I should care if a little oil transfer is goin on.
I have never heard of a trans or primary blowing up from the oils co-mingling together nor has it happened to anyone that I ride with.
Been riding these beasts for over 40 years and average 10-15k a year so i'm no newby but if ya'll want to throw good money at this be my guest.
Be safe

The MoCo loves you.
Ron

[PoorUB]

i just don't see why I should care if a little oil transfer is goin on.
I have never heard of a trans or primary blowing up from the oils co-mingling together nor has it happened to anyone that I ride with.
Been riding these beasts for over 40 years and average 10-15k a year so i'm no newby but if ya'll want to throw good money at this be my guest.
Be safe

You have your head buried in the sand?

Many of these oil transfers will drain the transmission in 1,000 or less. I don't call that "a little oil transfer". That is a big deal, unless you just ride to the corner bar and back. How would you feel if you spent close to $30,000 on a touring bike that you can't travel with? I have weekends where I might put 1,500 miles on. In the next couple weeks I plan on putting on few thousand miles. I don't see stopping every 400-500 miles and draining the excess oil from the primary and adding oil to the tranny. Co-mingling of the oil is not the problem. A transmission without any lube in it is the problem. It is a problem that with today's technology shouldn't exist.

[98fxstc]

i just don't see why I should care if a little oil transfer is goin on.
I have never heard of a trans or primary blowing up from the oils co-mingling together nor has it happened to anyone that I ride with.
Been riding these beasts for over 40 years and average 10-15k a year so i'm no newby but if ya'll want to throw good money at this be my guest.
Be safe

[attach=0]

[Mark P]

When I talked to Baker we didn't get into the inherent mechanical advantage differences of the 1.5 inch vs 1 inch piston.  Maybe someone could check if the Harley stock piston is actually 1 inch -- the Baker website info simply says its compatible with the stock H-D or 11/16 Master Cylinder.  What the Baker guy was trying to explain was that the stock HD piston was so close in size to the opposing nut size, that tranny fluid had a hard time getting squished out of the gap between the piston and nut, but with the larger bore Baker piston the fluid could escape around the sides of the nut.
I'm just the messenger on this -- the Baker guy seemed to be a true believer in this solution.  I think somebody with the issue needs to try this and report back if it's really a cure or not.
I've been holding off buying an M8 just because of this problem. so I don't have an M8 to experiment on, otherwise I'd gladly do it myself.

I have a guy bringing his M8 over to my shop this weekend and I'm going to try and install one of our covers. I let you know how it works.

I would hope it already works or why would you be selling it? A technical explanation of how it works would suffice. Not like anything can be kept a secret for long.
Ron

No secrets, had one of the engineers tell me our covers will not work on the M8's but he didn't tell me why. I'm going to find out what needs to be done to make it work if I can.

[Nastytls]

i just don't see why I should care if a little oil transfer is goin on.
I have never heard of a trans or primary blowing up from the oils co-mingling together nor has it happened to anyone that I ride with.
Been riding these beasts for over 40 years and average 10-15k a year so i'm no newby but if ya'll want to throw good money at this be my guest.
Be safe

So, in you opinion it is perfectly fine that my transmission had leaked the majority of it's oil in to the primary by the time I hit 1k miles? It is fine that my dealer has me coming back every thousand miles so they can change things out? That's just plain stupid. I bet you wouldn't have that ridiculous opinion if it were your car that was doing it. I shouldn't have to drain my primary and re-fill trans and primary every 1k miles on a $2k motorcycle, never-mind a $26K+ motorcycle..... If I do choose to ignore it my transmission will surly fail due to a total lack of oil as will parts in the primary due to being way overfilled.

Name a modern vehicle that you have to do that with other than the M8.

I actually like the bike overall and my wife is happy that I finally have something that I can ride with her, so I am happy that I bought it but this part of it is entirely unacceptable.

[ckwizard]

All i'm saying guys is everyone I know in the great state of Texas and all my ol buds in Michigan are not having this issue.
The only place I ever hear about it is right here.
Now if ya'll are truly losing a full quart of oil from your transmission that's obviously an issue, I don't have my head in the sand I just can't find anyone that is experiencing this problem live and in person.
Most folks I talk to absolutely love their M8 and are not having any issues.
I have been wanting a new Road Glide Ultra so obviously it's a concern but it's been difficult to validate anywhere off the interweb.

[14GuineaPig]

Read the Tech Article that Harley issued or are they making up the problem.

[Pete_Vit]

I never had an issue with my 93 Sporty loosing engine oil...until it did, it was a costly mistake on my part  I have no dog in this race, both my bikes are mid 90's bikes, I'd like to have a new bike but I can't seem to justify the costs right now, but I say to you, go for it, buy what you want, don't let the folks here sway you  and IF you have issues, these fine folks will still be here to help.

[les]

All i'm saying guys is everyone I know in the great state of Texas and all my ol buds in Michigan are not having this issue.
The only place I ever hear about it is right here.
Now if ya'll are truly losing a full quart of oil from your transmission that's obviously an issue, I don't have my head in the sand I just can't find anyone that is experiencing this problem live and in person.
Most folks I talk to absolutely love their M8 and are not having any issues.
I have been wanting a new Road Glide Ultra so obviously it's a concern but it's been difficult to validate anywhere off the interweb.

So, the guys in Texas and Michigan are measuring the amount of fluid that comes out of their primary and tranny?

[Hossamania]

All i'm saying guys is everyone I know in the great state of Texas and all my ol buds in Michigan are not having this issue.
The only place I ever hear about it is right here.
Now if ya'll are truly losing a full quart of oil from your transmission that's obviously an issue, I don't have my head in the sand I just can't find anyone that is experiencing this problem live and in person.
Most folks I talk to absolutely love their M8 and are not having any issues.
I have been wanting a new Road Glide Ultra so obviously it's a concern but it's been difficult to validate anywhere off the interweb.

So, the guys in Texas and Michigan are measuring the amount of fluid that comes out of their primary and tranny?

Kind of what I was thinking, if you don't know there's a problem, that doesn't mean there isn't one.
I have a friend with one, and I'm hesitant to mention any problems he might want to keep an eye on, because I want him to enjoy the bike. That doesn't mean he won't have any. We have a trip coming up in a few weeks, I might check his tranny when we get there.

[hdrider]

After all the comments after my original post about the Baker fix for the fluid transfer, I went back to the Baker Vendor Display at Black Hills Harley in Rapid City and had a detailed discussion with 2 additional Baker Technicians and I believe I've finally gotten some answers.  Apparently the original technician I had talked to wasn't as clear in his explanation or he may have left some details out.

What I found out today is:

1. Baker firmly believes that their Hydraulic Side Cover design solves the M8 fluid transfer problem

2. The M8 Hydraulic Side Cover is in Production, but not available to order yet.  The covers are in final machining and still need to be chromed.  Expect them to be available to order in about a month.

3. The specs on the Baker website for the 06-17 Hydraulic Cover are for the Twin Cam Cover -- not the M8.

4.  The Piston size in the Stock H-D M8 and new M8 Baker Hydraulic Cover are the same size and slightly smaller than on the Twin Cam (don't know why H-D reduced the piston size for the M8).

5.  The big difference between the H-D cover and the Baker cover is that the H-D cover has a piston stop as part of the casting.  The stop limits the piston travel so it can't be pushed out of the bore, however this stop extends beyond the piston and literally surrounds the nut on the tranny door -- this creates a pocket that limits the movement of tranny fluid which gets pressurized and pushed past the clutch rod every time the clutch is actuated.  The Baker design doesn't have a piston stop --  the piston could theoretically be pushed out of the bore, but in reality is limited by the clutch rod travel, and finally it would hit the tranny nut before leaving the bore.  In other words the Baker design leaves the Tranny nut completely unshrouded.  At least thats the way it was explained to me by the latest Baker Technician and a bit different than my original understanding (and posting).

This got me to thinking that if Baker says the problem with the Stock H-D M8 hydraulic side cover is the piston stop, then why couldn't the stock cover be machined to eliminate the piston stop?  Does anyone have a photo of the inside of the stock M8 hydraulic cover to see exactly what Baker is referring to and whether it's something a machinist could readily modify?

[hd06myway]

are these issues with the M8 real, and other ones the TC's experienced? Yes, to the people who have had them, is it 3 out of 4 owners?  No it's less than 1% of 250k bikes that are sold a year... the problem is the issues get distorted because 12 people on the internet talk about them all day long while the rest of us ride issue free for most or all of our bikes life... to this day I've never talked to anyone who had a tensioner problem with the old initial design not saying those who have are making this sh*t up but in terms of on the street... it's a non issue... if 12 people have a problem and talk about it daily on a website, it doesn't make it a crisis...