Engine/Primary/Trans OIL Question?

C

Calista T

New member
Ok, before you get ready to flame me or run for the popcorn, I am asking these questions after I have spent way too much time reading all of the searches that I have done here on this forum. Most searches run back 5 years and more.

My concern is that I have a 2010 Street Glide and more I ask the more I am confused. Either everyone here is a genius or we all are idiots. The service manual says to use 20w50 in all three holes. My local HD service manage says the same thing. Here is what I have found and learn (or should I say, not learned)

Engine:

Pretty much everyone agrees on 20w50 with a few suggesting 10w50 Mobile to save on the cost.

Primary:

Many suggest 10w40. Oils without friction modifiers. ATF.

Transmission:

Most say 75/90 Gear Oil and a couple said 75/140.


None of this agrees with my service manager or my service manual. I'm posting here in the Touring Section (instead of General Chat) to eliminate the shear number of "expert" opinions this could generate. Is this because the newer bikes are different from the older ones? Doesn't seem to be much logic to that assumption.

I would like some real/factual answers as to why you use something other than what is recommended in the service manual. I'm not looking for the all too common "Because I Like It" answers. We don't need to get into which brand is better than another unless a particular brand is the only manufacture of that particular oil.

I really would like to learn what works and why. Please just don't say what you use only, but WHY you use it. Give me a logical reason.

Thanks in advance,
 
I will bite. Running what your service manual says will be fine. You will get as many "opinions" as there are people out there. Just make sure what you chose meets the API rating, i.e., GL-1, GL-5, SG, SF, etc. and you will be fine and the right viscosity for your temp range.

Todays oils a very good products and all will work just fine. You will hear about the "old Days" but we are not living in the old days. Many myths and voodoo exist from the old days. Just pick a name brand oil with the proper API rating and viscosity and you will be fine.
 
vonzoog,

I think this is a good question as to why we don't follow the manual on oils.

1. HD is going to tell us to use what they sell and nothing else. Even though some dealers stock these "other" oils.
2. Many high mileage riders have found products that work better than the "one size fits all" oil.
3. I am glad I tried a couple different oils in the primary and gearbox. It simply works better.
4. I found that since I got married "this time" I have a lot less opinions. So no oil types from me. ;-)
 
In the automotive industry the tolerances in the modern engine are so tight they recommend oils like 5-30, now HD has much looser tolerances (but nowhere near those of the shovels/pans/knuckleheads) and thats why they recommend 20-50 oil. You can think of it as a very high mileage engine where one uses heavier oil to make up for the wear characteristics. So conversely a 10-40 may be too thin of a film for these tolerances.
For the gear oils the heaver the weight it has a greater shock load protection, and as far as the primary whatever else is put in there better be compatible with the clutch disc material. Just my HPO!
 
I believe you are sincere with the quarry.

I have to agree with your interest and I think I understand the question. If you get responses it may get moved any way. I have the HD syn in all three , only because they did the first 1K service and I wanted synthetic. I would use something different if I was convinced it would be better.
However....like you I read and re read and read more and it all blends together after a while ...for every pro for one over the other, there is also a con against it. Someone likes it someone doesn't.

You can follow the manual and the moco advice, or see what others are using and select one and give it a try, if you like it stick with it , if you feel it is not right ,try another. Most of it is preference, either you believe it increases power, makes it quieter, cooler, smoother, faster, shine more ,or just like the looks of the wrappper, or the sound of the name of the product...whatever. I think it all boils down to what YOU determine is right for YOU through YOUR experience..
 
Look, here is my opimion for what it's worth. Syn 3 has poor to no detergent. It allows carbon to build up and this causes heat. I use mobile 1 and at my first mobile 1 oil change the carbon was easily visible in the oil. No carbon since.
ATF probably has no adverse affect on primary chain or clutch, but the tranny bearing is housed in plastic. I noticed that in threads in this forum there appears to be a corelation between ATF and tranny bearing failure.
Redline V-twin with shockproof is thin enough not to cause extra heat from thick tranny fluid and helps some with the clunk.
 
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