I was at my local dealership a few days ago (12-13-19) and there was a guy at the service counter (I was next to him at parts buying oil change related stuff) complaining that he has to add oil to his transmission on his new 2020 street glide after he travels to see his daughter (all interstate ride 70+ mph one hour there and 1 hour back he said). He said riding below 70 mph oil doesn't disappear---- said he was really concerned and couldn't figure out what was happening. The service guy told him he had never heard of that issue before and that he probably just wasn't filling it properly. I couldn't do anything but SMDH. I've been reading about this issue on Harley tech talk forum for years and here it is 4 model years later and still happening (even with the primary vent apparently). I have worked in manufacturing for the last 35 years and can honestly say there is zero excuse for this type of "ongoing" design flaw on a product ---- especially one that costs this much. This issue alone is the reason I will keep my twin cam touring bike into retirement instead of buying the new HD I was planning to (Currently at 43k miles with only repair being a new brake light switch). I didn't have the heart to go outside and tell the dude he had an issue that HD has let fester since the MW8 first come out in 2017 and he should pop off his derby cover to let his primary get back down to the proper level. HD ENGINEERING MANAGER --- YOU SHOULD HIRE A GOOD ENGINEERING CONSULTANT TO FIGURE OUT THIS ISSUE FOR YOU AS APPARENTLY YOU GUYS LACK THE ENGINEERING TALENT OR HAVE SUCH A LACK OF ENGINEERING LEADERSHIP THAT YOU ARE COMPLETELY UNABLE TO FIX THIS ISSUE PROPERLY. THERE IS NO SHAME IN ADMITTING THAT YOU ARE IN OVER YOUR HEAD SOMETIMES AND NEED SOME HELP. THE SHAME IS IN SELLING PEOPLE $30K+ TOURING MOTORCYCLES THAT THEY CANT TOUR ON WITHOUT THE RISK OF RUNNING THEIR TRANSMISSION DRY. THE MANUFACTURER I WORK FOR HAS BROUGHT IN CONSULTING FIRMS NUMEROUS TIMES OVER THE YEARS TO SOLVE TOUGH PROBLEMS SO I KNOW IT CAN BE DONE. ITS WAYYYYY PAST TIME TO FIX THIS ISSUE

Doc you are the reason why I trust true Harley Davidson Tech's , thank you .

That was an amazingly well detailed and descriptive explanation of an issue I never even knew existed!

I am one of the “lucky” few who has experienced the oil transfer issue. Took a 2800 mile trip and 11 oz. of oil transferred from the tranny to the primary. I have since fixed my issue but find it very discerning that Harley claims it tests its engine design thoroughly before release, yet this issue has been around now for multiple years. Thanks Doc,well explained.

Sounds like Harley should install it and do it for free seeing as how it’s a manufacturing issue. Anyone else think so?

Hi Doc, Great explanation!! I am one of the “lucky” few, 2019 Road Glide Special. Vent kit installed at 5000 mile service. My theory is the type/frequency of riding is why some bikes see the issue and others do not. I ride to work daily, 63 miles each way, about 60 minutes of travel time highway/80 minutes backroads. If the clutch rod tolerance is too loose the “churning/blending” will cause the transfer and the longer/harder you ride the more chance the issue will show up.

Thanks for the video and I have one correction for you. This is not a “rare” problem! My 19 RGS did it from brand new and two of my buddies touring bikes now have vent kits installed.....so far from rare. My biggest question is....what damage has been done to my trans since it ran 12 OZ low on two occasions (in the trans) for hundreds of miles which definitely affected the ride ability of my bike. The shifting became very “clunky” due to the low oil level and the clutch didn’t perform correctly due to the primary being overfilled. As a consumer.....Harley should be extending the warranty on these power train parts for a minimum of five years total so customers have piece of mind due to Harley’s engineering mistake.

It’s a Joy to watch your videos , I’m learning a Lot !!

Great job Doc, excellent description in laymen’s terms. Thx

Thanks Doc. Look forward to your weekly videos.

outstanding explanation and great video. Thanks so much for doing this.

Thank you sir for the video and this important information.

Very informative, thanks for all you do Doc!

An excellent explanation of the problem(s) and solutions! 👏🏻

Excellent description of the HD oil transfer problem.....Thanks Doc.

Thank Doc you are the best . Keep it coming.

Thank you! This is the most accurate explanation of the oil migration problem! Bringing my 17 street glide special in ASAP

WOW! GEEZ! thanks so much for your channel and your time to teach us all these things. I mean everything your channel provides!

Thanks doc, top notch information as always, appreciate your time and effort. Merry Christmas

I appreciate the video but there are a lot more affected bikes than you are alluding too. It’s a fairly big issue. I’m glad there is an apparent fix now. Harley now installs this vent on the 2020s from the factory so they are aware of the magnitude of the issue.

Thank you, Doc, for an excellent explanation of an issue that has gotten a lot of lip service and speculation! 👍

Doc fantastic video!! It's great to have someone explain that's knowledgeable, and doesn't treat the student like a fool. Racing and wrenching for more than 50 years. Well not racing anymore!! Lol Thanks again Tom

I've seen this in my 2017 FLHP with an M8. My dealer is aware and we are following the process outlined in your video. This video is the best explanation yet of the problem. Thanks for the info and you get a new subscriber.

Appreciate the detail in your vids, you are always so clear and concise. I'm sticking with my 2013 twin cam...she's solid as a rock haha! 🤘

Thanks doc I appreciate u explaining more in depth about what this all about. I have a 2019 Electra glide standard that had this fluid transfer issue and they had to install this same vent kit at like 275 miles I have a little over 5k on here now and so far so good....but when I asked my dealer what they did they seemed like they didn't wanna say all they said it's been corrected and didn't really explain what they did. Thanks again for this explaintion.

Thanks Doc you explained it clearly. Really appreciate these videos they are very informative

Always a big help Doc! Thank you for all you do!

When I was working on the transmission on my 2009 Dyna I was wondering what kept the oil from the primary and the transmission because of that hole in the shaft the main shaft I asked Harley-Davidson about it but they didn't know so I'm glad I saw this video this explains it perfectly.

Quality information, thank you. It feels like the motorcycles (rare Touring model) that are experiencing this, is because how they are ridden. Long stretches of Highway miles under heavier loads. Thanks again.

great explanation. now I finally understand. on many of the group discussions it is so confusing. people need to understand that this happens to cars too uggggh. they are so complex anymore there is bound to be something. that is why we have warranty. and I wonder too those who are blowing out their engines to larger displacement contribute to this issue.

Hey Mike !! was You tubing and your video popped up on my Feed, Excellent Video, Nice Job !! I Miss South Carolina, i became an Ast. Manager and then a Dealer manager up here in New England, but because of a health issue i was forced to Retire, i now ride a Honda Goldwing F6C Valkyrie and manage a small independent shop in the summer. Hope Everyone Down there is Well, i'm always talking to people about my time there.

I wish my local dealership would have Techs like you. They are not. :(

Awesome video. Thank you, Doc for the very detailed explanation. As someone already request it, I also request a video on the M8 oil sumping issue. Unfortunately, as it is already happening in the comments of this video, there is too much comments complaining about Harleys instead of focusing on the issue.

GR8 INFORMATION VERY WELL SPOKEN! THANKZZZ!!!!

Awesome video I have a 2019 street glide that had this issue. It was a little upsetting having a brand new bike that would almost drain the transmission in a 1000 miles. Needs to say the dealer documented the issue. Then had me drive it around for 500 miles and rechecked. They did the update kit and so far I had zero issues with fluid transfer. The bike now has over 5000 trouble free miles.

Thank you. I was one of the unlucky ones with the oil transfer issue on my 2017 M8 Street glide. The local dealers went through the appropriate steps outlined for them from Harley (Milwaukee). The first attempt was the "deflector" as you described and clearly showed in the video and then finally the vent tube when the deflector didn't work. FYI, the transfer would happen within the first 1000 miles after the levels were set and checked in the transmission. All is good now. Thanks again.

Great video, well explained! I don’t know how true it is, but I know a guy that had the issue on his ‘19 SG and said the first sign for him was difficulty shifting gears (likely due to low transmission oil). I assume you wouldn’t notice though unless you lost enough transmission oil over into the primary.

2nd time watching this video. This vid helped me diagnose a customers problem in 5 minutes. Parts ordered and repair to come. Thanks for a great heads up video.

Great explanation and history on this. Thank you.

Thanks Doc! Really appreciate the explanation and fix.

No wonder there is oil coming out of the derby cover when I didn't refill the primary after replacing the starter clutch. Took about a 200 mile journey before I realized I screwed up. This video makes me feel like less of an idiot. 1st harley for me , 1984 fxrs . My favorite bike I own. Great info thank you.

I bought an 18 Road Glide Special new in April 2018 and had a dealer installed Stage 3 build. Got 48k miles on her now and have had no issues. Can't complain. Thanks for the info Doc.

My 2018 FLXS now has the slinger (which didn’t help) and the vent. So far the fluid is staying where it belongs. All free of charge. Thx Doc and thx Harley D!

Just had a 2019 into our dealership with the recurring oil transfer problem . Bike has a couple thousand miles on it since we did the breather install. Keep trying Harley.

what could go wrong you drill a precision placed hole with a PAPER template

One of the better videos I've watched. I'm pushing 25 years as a Harley mechanic, first at a dealership and now (part time) on my own for the past fifteen years or so. Good explanation. I'll be back to watch more if a situation arises.

Good video but 12 bikes out of our 22 bike group had the problem my 19 RK empty the transmission every 500 miles so did 2 others Harley install the vent tubes in them so far it has solved the problem

I really enjoy my 88 carb'ed Twin cam ... just so many less issues.

Great & informative video Doc. I would not say this is a common problem.....but I would definitely not say it is "rare". From sumping issues to the transfer issue on M8's, has made me decide to keep my 2015 Ultra.

Great video and thorough explanation!

Very informative! Although for the Harley guys I’ve talked to locally with the issue, they would have not made it to the 5k mike inspection interval because the transfer was so great.

My 2019 RKS had this issue and my Harley dealer installed the breather tube free of charge to me. Thanks for the detailed explanation!!

Had mine done right after delivery of my 2019 RK Special in April. I do my own wrenching and my first oil change at the 1000 mile mark I said " gee thats not right" Did all three holes then went to my local HD dealer and my mechanic said yep it's a problem. That day they put the fix in and now trouble free at 5400 miles. Glad HD fixed the problem after the builds dates of May 2019 and installed this on I think all hydraulic clutch models. Great vid for those who didn't know.

Great info, thanks

Great vid. Thanks for the effort. Love my 2012 EG. Does all I need.

Great explanation. I had the issue on 2018 RKS and I know you say it is rare and on just a few but the issue is much larger than you state. I know 6 buddies in the local HOG chapter that had the same issue Harley was a PITA to work with initially and denied it was an issue. Said it was how I rode the bike!! LOL Finally they did the dye test and it transferred 6 oz in 500 miles. The oil deflector was installed and the issue got worse. Transferred 19Oz from Trans to primary!! I ordered a 3rd party push rod and problem was solved. I had them install the last kit as a precaution. Great explanation of the issue but Harley knows this is a bigger issue as they now install the breather on new touring bikes.

Great video, well explained without the hype.

My 2017 FLTRU had the issue. Dealer put in the Primary Vent kit and it it helped with "short trips" but didn't solve the issue for long trips. (I was right at 5oz in 5k - annoying). Dealer recommended, and I tried, the "Greg Williams" oversize clutch rod. Turns out after I ordered it, that the previous owner had already installed the Greg Williams oversized rod - so I contacted Macomb County Choppers and advised them I already had one installed - but still had transfer. "Greg" contacted me directly and said "harley had two diameters in the M8 clutch rod "center shaft openings", and after some q&a "Greg" decided I should try his "slightly even larger" oversize rod (he apparenetly offers two sizes of oversized clutch rods). He sent the slightly larger version of the oversize clutch rod - thank you - and I installed it. It moves freely back and forth with very little side to side movement. So far seems great.

very good video, very detailed, good explanation Thanks Doc.

Thanks ,great explanation.

"Very few of the touring models". I personally know 4 people with M8 equipped touring bikes, a 2017, 2 2018 and 1 2019. 3 of them have the transfer issue. In two, the vent kit fixed it (after months of back and forth with their dealer and HD customer service). On the '17, they installed the flinger, which didn't fix the issue. Basically they shrugged their shoulders and said too bad. He wound up going to court over it. Between their failure to introduce a fix in the manufacturing process and the struggles to even get the problem acknowledged by those who have had it, I no longer have plans to buy any more new Harleys.

I really enjoy your videos... I have a better understanding of how my bike operates. Thank you :-)

Great Video Thanks Doc.

This all got started when HD moved the throw out bearing to the pressure plate. I see a lot of bikes with the transfer problem and there is a fix that moves the throw out bearing back to the side cover side. It works and no more worries.

Terrifically well explained 👍 ! (As usual dear Doc 😉) Luckily, on my FLHRCI 2004, I never noticed such transfer oil problem. At around 65'000 km I had to make changing the shifter shaft seal (leaking)

what a great video on a way overblown issue

Thank you. Good job.

Doc you are the friggin best! Nobody on the internet has addressed this problem with the level of expertise and explanation you have and you did it flawlessly. I just bought an M8 touring and this will make me sleep easy and enjoy my motorcycle more knowing the only known issue with the 2020 and newer M8’s is explained in the way you have. Keep making awesome videos! One day I’ll ride the 1400+ miles to come meet ya and say hi!

Doc you are a good "yes man" for Harley Davidson.

I had this issue with my 17 SGS. It would happen at the 1500 miles every time. Harley Davidson documented and then put the kit in. Thank goodness it was still under warranty.

Thanks for the careful and detail explanations of both current and history. Would seem like for the M8’s this should be the default leaving the factory going forward. Again I appreciate your videos and detail breakdowns. Cheers!

Thank you Doc, that was an excellent breakdown, and history review of this problem. You explain things very well. I will make a note though, that maybe in the grand scheme of things, with how many bikes are sold, how many people actually document fluid changes and levels, that it's a "few or rare event", however it's happening to a lot of bikes. I did the kit myself on a 2017 SGS, and you are correct in the fact that in most cases the dealership should do this, not the customer. I'm a mechanic by trade so I was more than comfortable doing it, but the template definitely leaves some room for error due to the distance from paper to center punch in primary, and angle can throw drill location off, and if you don't thoroughly evaluate before drilling you could find yourself either too low or even into the starter housing if too far left. Mine was spot on. Thanks for doing the video, and keem em coming.

I have a 2019 Sport Glide (M8) with no mods to the engine. Have had my 3rd service done and over 12,000 miles on it in 9 mos. Zero issues with transfer. Absolutely love the bike and she's my main transportation.

Killer job on that one Doc.

I have an 18 rgs had the vent put in under warranty at 12000 mls at 17000 working great

Oil transfer happening on only a few touring models sure does seem like a larger problem when the few includes mine. Had the primary vent installed and it's been good ever since.

Well explained! My Harley uses the motor oil has transmission fluid. No worries here.

The Mud Dobber Wasp is going to love it! Thanks Motor Co. !!!!!WTF??? Needs a filter on the vent hose.

Just had the breather "fix" done on my '18 FLTRU at 16.8k miles, at a pre-emptive 20k service prior to a cross country trip coming up. Approx. 10 oz of fluid transferred since 12k mi service. Mine's a 107 w/ S2 Tq Cam, breather, SE tuner.

Thank you very much for your explanation. I have this problem on my 2017 road king and they always denied it in Buenos Aires. Today I continue with the same problem but with the pandemic I cannot go 9 months ago and the warranty expired ... Harley Buenos Aires

I no longer have any worries or concerns after seeing that impressive paper template.

Doc, this video needs to go on HD's website somewhere to calm the hysteria. I have a 18 Sport Glide Softail and was paranoid that this was going to effect my bike and ruin my engine. I had no idea it was limited to rare occasions in just the touring line-up for the Milwaukee 8's. Thanks for the great info, as always!

I am fortunate that my bike is not having this issue. 28,000 miles and all good. Good job as always on explaining the problem.

Great information

Another great video Doc. Thank you. It seems like the M8 touring bikes with Twin Cooling systems are having all the issues.

very good. thanks man.

Thank you !

This just happened to my 2019 FLHR with 1000 miles on the ODO _( dry transmission dip-stick checked on side-stand after riding),_ and the dealership told me that are going to install the "kit". The service department said that they rarely ever see this issue ;) Har Har.

Thanks u said it great

Doc that was a fantastic explanation!! Thank you. I'm curious why the vent wouldn't be installed on all bikes from the factory? I'm also curious if when this vent is installed into the primary does it affect or stop the oil from entering the cleaner or throttle body?

Nice looking Twin Cammed FXRT there, not what you expect to see in a dealer shop Doc,

I am experiencing this problem on my 2018 FLHTK. I have my own theory from my personal experiences. I have been doing my own servicing on my Harleys for over 20 years and am a retired auto/heavy equipment mechanic. What I have experienced is that my 2018 M8 will not transfer trans oil to the primary when just riding casual rides. Only when riding long distances at highway speeds in hot weather, do I experience oil transfer in sufficient amount to be concerned. Every year I take 2 vacations with my wife and actually tour with my M8, this is when I experience transfer. Long days riding interstate highways, racking up the miles for hours at high RPMs. Usually in late July and August when temps exceed 80 degrees. This may be the reason it is showing up to be a rare problem and why it is only affecting Touring models. We know most riders are going out for a weekend ride in the country on back roads enjoying the scenery and a casual ride. I think this type of ride negates the problem. I would like to get the warranty but do not want to go through the process of 3 dealer oil changes and the miles back and forth to my dealer. Also I would have to recreate the issue by touring long distances between all 3 oil changes. This will be expensive undertaking. I've seen many different remedies for this problem and many reviews saying they don't work. I know this was 4 years ago, but has HD come to a final conclusion? Also, I appreciate every video you put up and wish I was close to your dealership to have you service my Harleys! Keep up the good work!!

Not an issue on my old 2011 96 cu in Ultra.........so far :) Great video, very well explained. Now I will be keeping better track of my levels, however 5 oz doesn't sound the end of the world to me, 11 oz you would notice for sure.

Great video

That was informative Doc. I own. 2019 Ultra Limited and as luck would have it, I had the oil transfer problem and venting kit was put on my bike. This in my opinion could be considered a Mickey Mouse way to fix the problem. I recently learned that a Greg Williams designed new push rod is available with a larger diameter and a flat side. Fixed in ten minutes by the owner and problem solved. Look I love my bike but Harley could have stepped up a hell of a lot better.

Great explaination of the problem and fixes for the novice. My 17 SGS thankfully doesn't have this issue. My hang up is the fact that even though Harley has identified the problem and developed a fix they make the customer put up with 3 trips back to the dealer and 15,000 miles of riding before they will fix it. Most guys I ride with do their own wrenching and oil changes. If its broke Harley should fix it, period.

I will do this on my Road Glide Special 2019.

I've noticed/check brand new Harley touring bikes have the vent kit install from the factory.

Happened on my 2020 Softail last week!

All motorcycles are built the same... If the issue is a problem on one it can be a problem anytime on another. thanks for the explanation.