Harley Transmission "needs"

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Ah, Ok, I understand your point, yes, to each his own if one decides to step outside of what Harley recommends in your owners manual. I do understand what you are saying regarding the primary plus.
Only 2 fluids recommended for 2014 HD RK Transmissions.

For me personally, if they do away with Primary+ I will use a 20/50 oil in the transmission and primary. Harley does with their syn 3 and the Syn 3 is a GL1 oil vs the GL4 or 5 people are putting in (gear lube) At least with 20/50 oil your in the same class of lubricants.
I also found on Mobil 1 site regarding the transmission to use what the owners manual says, I think since Harley Davidson uses 20/50 engine oil in the transmission you will be good to go vs. gear lube ....

"These products will help provide excellent performance in motorcycle engines that are designed with a common engine/transmission lubrication system or where the engine lubrication system is separate from the transmission system. In the case of the latter, follow the manufacturer's recommendation for the type of fluid to be used in the transmission. "
Mobil 1 site
 
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Originally Posted By: alarmguy
...
I also found on Mobil 1 site regarding the transmission to use what the owners manual says, I think since Harley Davidson uses 20/50 engine oil in the transmission you will be good to go vs. gear lube ....

"These products will help provide excellent performance in motorcycle engines that are designed with a common engine/transmission lubrication system or where the engine lubrication system is separate from the transmission system. In the case of the latter, follow the manufacturer's recommendation for the type of fluid to be used in the transmission. "
Mobil 1 site


So it seems perhaps even they aren't clear on it, they have revamped the site and it seems like there is less information there now, particularly the "ask Mobil" archives.

But in their answer to this question:

What oil to use in Harley Primary Drives and Transmissons

They did not dispute the use of gear oil in the transmission.

I too will probably be moving away from SYN3 in the 2014 on the next service. The engine and primary I have no issues with, but the transmission recommendations are all over the place... Baker transmission is clearly in the GL5 camp, Amsoil appears to be in the 20/50 camp, Redline and Spectro appear to be in the gear oil camp - probably what this means is that it doesn't matter a great deal.

Still like the OP asked it would be interesting to have a discussion about technical properties of either the transmission or fluids that make one fluid more suitable for a Harley transmission. Also if the transmission is a 5 speed or 6 speed has any bearing as has been suggested in some discussion on the Harley boards.
 
Yes, agree, lots of theories and speculation and HD doesn't make it easy to do the right thing unless you use their product.
I will continue with Primary+ in the transmission and primary (maybe) as long as it is sold, I like to see facts if I was to change that something else is better.
There was on post by someone, somewhere, where a Harley Mechanic showed the blackened bearing races from HD transmissions and stated they all came from bikes using gear oil. I have no idea, AGAIN, how true or accurate this post was but it did add some creditability as the mechanic said does it make a difference, he didnt know, he just knows that you can tell heat was causing these things to change color... And honestly, I'm not so sure I am posting this 100% correctly except to say, the mechanic did show him the bearings and races he saves to show people what comes out of transmissions with gear lube.
Again, all speculation and I am guilty of adding to it, without confirming.

So for now it's still Primary+ for me, I was under the impression, based on other posts who are much more into this then me,that the P+ was simply a quality low additive mineral oil but we don't know, it very well maybe engineered just right for the HD transmission, much like more and more automotive companies require a certain antifreeze and more and more so, automakers requiring certain standard oils with their "seal" on it or it could just be a money making scheme. Dexos etc.
 
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I have to say it's nice to have the debate without things turning toxic when there's differing arguments or god forbid conjecture. For me, I still learn stuff from the debate.

As far as my original post goes, I'll see how I feel when the time comes but I may well experiment a little in the transmission if nothing else than to see if I notice anything in terms of a difference in feel a opposed to the GL5. The whole question is more academic than practical anyway since I don't put on that many miles in the first place where I'd be changing the transmission lube very often. My chain of priorities with this lube stuff is always proper protection, limiting the variety of oils I need to keep stock of (between cars, street bikes, dirt bikes), and not wasting resources by throwing away good oil for no other reason that I'm ill informed. In that order of priority. Notice being cheap isn't in that list.

So who's going to be the first to throw Rotella in their Harley transmission???? haha
 
So I e-mailed Mobil this morning. (quick response too)

They said use V-Twin in all 3 holes. (WRT to my 2014 anyway)
 
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I have an 08 street Bob highly modified with 107hp/115tq. 100tq at 2200rpm.
Anyway I towed the syn 3 line in all three holes til I smartened up and be an using the right fluid in the application.
So I use rotella 15w40 in the engine and primary with 3000 mile intervals and redline shockproof heavy in the transmission.
No more clunk into first,shifts far smoother and no viscosity loss at the recommended interval.
Gear oil in the transmission is superior because that's what it's made for.
Metric bikes use a common sump and ya they run fine however because my bike has 3 holes why not use lube designed for the application.
As far as Amsoil goes they won't recommend something different then the oem does. They just don't. Even if they know better they won't cross the oem recommendation.
Which is why they recommend their v-twin in all holes.
I've got 10 quarts of their 60 grade left but I like the Rotella better. More pep
 
Yes, agree, this was a "civil" thread ... My bike is almost brand new, only 2400 miles. Ive always been into properly taking care of my stuff. Its been a way cooler then average winter here in SC and did not get much riding time in, only have been able to get out every couple to few weeks this winter. If its warm its been raining, frustrating!

Im not sure what I will decide on using before my before summer oil and fluid change.

I changed the engine oil, primary and trans oil at exactly 1000 miles. Once the weather is firmly going to stay warm here, maybe late March - early April I am going to do one more change in all three holes.
At that point the current fluids will only have about 2000 or so miles on them and bike will have 3000 miles. I do this change to flush out any remaining break-in metals once and for all.

At this point I will be inclined to stay with the conventional HD 360 20/50 in the engine and Primary + in the other two holes. As silly as this might sound to some others I want to stay in the "range" of recommended fluids HD requires and be able to prove it in case of major problem requiring warranty work.

So anyway, if I do use something different in the engine, for now I am thinking of an oil I found that Amsoil makes (forgot) the name but not motorcyle oil, a general 20/50 synthetic for the engine, its also carries the Diesel CH or higher rating which HD has in the owners manual as ok. Plus of course SG.Sh etc ... on the automotive side.

For the Primary - Either the Primary+ or Valvoline 20/50 motorcycle oil. I have used this oil on other bikes, I like the firm ever so slight grabby feel of the clutch with this oil.

For the transmission - Either the Primary+ or a 20/50 oil of my choice that I have not decided yet. Maybe even the Amsoil.

Ok, off to work I go ... (all the above subject to change!*L*) Early April is a long way away.!
 
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Since the OP addressed the transmission, that's what I will talk about. Like I posted earlier I always use gear oil because....wait for it.....there are gears in the transmission! I've used gear oil in all my Harley's since 1981, NEVER a problem in over 300,000 miles. 4 speeds, 5 speeds, and 6 speed transmissions. I think that's a pretty good indication that gear oil works. My 1988 FLHS has just over 200,000 miles on it and it still runs great. Interestingly enough, my buddy once had to replace a 5 speed bearing and I think he uses 20w-50. I'll have to ask him on that.
I don't pay attention to what HD says because they used to tell you NOT to use synthetic oil. Having said that, I've always used HD specified lubes while my bikes were under warranty just to avoid any possible problems. Once out of warranty, I use what I want.
 
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Alot of people don't understand what can and cannot, void your warranty. Using an oil that is not sold by Harley will NOT automatically void your warranty, per the Magneson /moss act. Years back Harley tried to say that if you bought a Harley you HAD to use their brand of oil. The Magneson /moss act say's if that is the case, Harley or any other vehicle manufacturer for that matter , had to provide that oil free of charge. Harley changed their stance on that, and can only strongly " recommend" their oil be used. That's why in the the manual it says to use Harley's oil first, or an SAE rated equivalent oil.Say if you used automatic transmission in your primary or motor, that would be a good case for denying a warranty claim.Beside that, the burden of proof is on them to prove what you used actually caused your problem.,,
 
Originally Posted By: blueglide88
Like I posted earlier I always use gear oil because....wait for it.....there are gears in the transmission! I've used gear oil in all my Harley's since 1981, NEVER a problem in over 300,000 miles. 4 speeds, 5 speeds, and 6 speed transmissions. I think that's a pretty good indication that gear oil works.


I think gear oil today in a transmission is as for sure a bet as it gets, aside from potential GL5 corrosion. But is it needed or overkill? That's the question we'll just need to leave open it would seem. Your experience is pretty common, plenty of people can attest to it, gear oil plays well with gears in the transmission and you can't go wrong. But again, was is due to it being gear oil, or would any other decent 20w50 or 15w40 diesel oil got you just as far? We can leave that one to float around the universe.

If nothing else we got to talk a lot about "transmission lube", that doesn't happen every day. Anyone else get creeped out a bit every time you type that?
 
Originally Posted By: MoreCowbellAz

Last thing…….I never think twice about putting diesel oil in my dirt bike or road race bike, and those bikes all have shared sumps. But for some reason it feels weird to think about doing the same in my Harley, no idea why. Hence, my looking for facts.



You can do it. I always used Syn3 20w50 in my Sportster and it was fine. BUT...you have to change it every 5000 miles. If you have a RK then your RP gear oil can go 15-20,000 miles per fill. So that right there is the reason to use gear oil in the trans. Next fill try some 75w140.
 
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Good point. I'm all about reducing time and labor with extended OCI's. The nuisance factor is a bigger deal to me than the cost factor. I do think RP is way overpriced though. Impulse buy for me.
 
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Originally Posted By: MoreCowbellAz
Originally Posted By: blueglide88
Like I posted earlier I always use gear oil because....wait for it.....there are gears in the transmission! I've used gear oil in all my Harley's since 1981, NEVER a problem in over 300,000 miles. 4 speeds, 5 speeds, and 6 speed transmissions. I think that's a pretty good indication that gear oil works.


I think gear oil today in a transmission is as for sure a bet as it gets, aside from potential GL5 corrosion. But is it needed or overkill? That's the question we'll just need to leave open it would seem. Your experience is pretty common, plenty of people can attest to it, gear oil plays well with gears in the transmission and you can't go wrong. But again, was is due to it being gear oil, or would any other decent 20w50 or 15w40 diesel oil got you just as far? We can leave that one to float around the universe.

If nothing else we got to talk a lot about "transmission lube", that doesn't happen every day. Anyone else get creeped out a bit every time you type that?




Using gear oil may be overkill I really don't know. Look at Sportsters. The engine and transmission share the same 20w-50 oil. Do their transmissions wear out? I can't answer that because I never owned a Sportster long enough to know. I do know people who have blown the transmissions on a Sporty. but I think it has more to do with revving them higher and beating on them more than a Big Twin.
 
Lets look at what happens in a motor VS a transmission. A motor need lubrication between a hundred various parts. A trans needs lubrication on gear teeth, a few bearings and shafts. A motor generates heat, and products of combustion. A trans doesn't create heat and does not produce products of combustion. The motors oil job is to dissolve the products of combustion, and remain in grade. The trans does not need the same detergents. The trans gets hot mostly from it's physical connection to the motor, and by some friction that occurs internally, but not as much as the motor does. So while motor oil and gear oil are approximately the same viscosity, they have different ratings on the bottles which make people think gear oil is 2 or 3 times thicker then motor oil. Motor oil gets dark after use ,while gear oil looks the same after use, even without a filter. A transmission oil doesn't need the same levels of additives a motor oil does. So In a big twin transmission there are only gears, shafts, and levers, and from looking at an exploded view of one, I do not see any brass or yellow metal parts that may be effected by using a GL-5 rated gear oil. So Using a gear oil in that application seems more of a better, cost effective idea then using a motor oil. Being it's designed for use in a gear box, gear oil has to be more shear resistant then motor oil. I'm pretty sure gear oil service wise, will last longer then motor oil will in a transmission. Look how many people change their motor oil in their cars, but never change the trans or rear end oil and drive their cars over a hundred thousand miles.,,
 
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Originally Posted By: blueglide88
Originally Posted By: MoreCowbellAz
Originally Posted By: blueglide88
Like I posted earlier I always use gear oil because....wait for it.....there are gears in the transmission! I've used gear oil in all my Harley's since 1981, NEVER a problem in over 300,000 miles. 4 speeds, 5 speeds, and 6 speed transmissions. I think that's a pretty good indication that gear oil works.


I think gear oil today in a transmission is as for sure a bet as it gets, aside from potential GL5 corrosion. But is it needed or overkill? That's the question we'll just need to leave open it would seem. Your experience is pretty common, plenty of people can attest to it, gear oil plays well with gears in the transmission and you can't go wrong. But again, was is due to it being gear oil, or would any other decent 20w50 or 15w40 diesel oil got you just as far? We can leave that one to float around the universe.

If nothing else we got to talk a lot about "transmission lube", that doesn't happen every day. Anyone else get creeped out a bit every time you type that?




Using gear oil may be overkill I really don't know. Look at Sportsters. The engine and transmission share the same 20w-50 oil. Do their transmissions wear out? I can't answer that because I never owned a Sportster long enough to know. I do know people who have blown the transmissions on a Sporty. but I think it has more to do with revving them higher and beating on them more than a Big Twin.




Guys I misled you on this. It's been a few years since I owned a Sporty. The transmission and primary share oil, NOT the engine and trans.
 
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