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What wrong with SYN3 in all 3

Either will work about the same but I prefer the Spectro coming from the M1 gear lube. I tried both the 75/90 and 75/140 M1 and really didn't see much of a difference between them. I would say if you live or ride in a very hot area, you would be better off with the 75/140 in there.
 
H.D. oil comes from CITGO, right Top? I won't even LOOK at one of their stations or products, much less buy it.

I have read an article (Donny Peterson on oil) in this forum from American Iron part 3, where he stated Harley oil is in bed with Sunoco and has been for 20 years, so which one is it?? Citgo or Sunoco??????
 
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So in the last, say ten years, how many Harleys had engine failure due to an engine oil. I thought as much. Yes there were a few new motors where the oil was so “slick” the bearings slipped on the shafts instead of properly spinning, but that was also tolerance oriented and very few reported cases. My current ride was purchased from an oil research annalists. He used Amsoil.
Some oils work better in YOUR bike due to many immeasurable variances. Gear mesh, liner, bearing tolerances, wear, contaminants, temperatures and a hundred other things in where certain viscosities, work seemingly better at certain times, and that is probably an ascertainment based on your “ear”.
Shifting is really nice on my bike using Mobil 1, down shifts into neutral smooth too,, but in the same year bike ’02 fatty, my friends bike clunks so he uses dyno oil and gets best performance with that mess. Great in mine, clunks in his,, why? Immeasurable variances?
Bottom line, I think is most of today’s oils surpass our needs, finding one that suits all the variances in your particular ride and produces what “sounds or feels” the best will ultimately vary. Most riders don’t enough miles on their bikes to make a long term difference anyway. So use what seems to shift good, keeps engine noise down, check your drain plug for metal when you change oil and be happy.
:rider
 
I've used my last quart of oil from H-D. I use Mobil 1 V Twin 20-50 in the crank and Mobil 1 75-140 in the trans. What weight should I use in the primary and is a full synthetic OK to use. I don't want to have to replace the clutch before it's time. Chavez can "KISS MY #%@*":mgun
 
Pretty much any oil will work in the primary like 10-40 or 20-50 but without friction modifiers. Synthetic oils have been known to cause some clutch slippage as you get some miles on the clutch.
 
I've had 9 diff bikes in my life, only 2 Harleys. The 1st Harley was a 69 xlch back in the 70's, which was nothing but problems, now the 07 Heritage with 9.4K on it is no question the best I've owned...
I have read and read about all the different oils and their claims that each one of their oils are the best....
I have also found that every HD item I have bought so far has been top quality and completly happy with them.
So my question is not which oil in what hole is better than the others.
My question is with Harley knowing what should be the best oil in a harley (WHAT IS WRONG) with the Syn3 oil which Harley offers and the dealer recommends in all 3 holes??? :wall


As stated above I have read a lot of articles this past winter, so this spring (May) 10k checkup I had dealer install syn3 in motor and forumla+ in the other two holes to keep HD service dept happy on new bike..
So far the motor still sound and performs the same. I believe the tranny is shifting better and 5th gear is quieter and it is a lot easier to find nuetral when needed.
Nothing else was done oil wise and so far happier with this change...
 
oct1949

If you are happy with that change, you would be ecstatic with a quality gear oil in the trans and a full synthetic in the engine instead of the syn 3.:s
 
I read this today and I decided that Amsoil 20w-50 MCV would be best for all three holes. I know most of you think gear lube is better for the newer Harley transmissions but I can't help but think that most people are just following the leader when it comes to using gear oil for these transmissions.

"With AMSOIL MCV, there is no need for separate transmission or primary chaincase lubricants. It is absolutely shear stable and will not thin out from mechanical activity. AMSOIL MCV performs like a gear lube without the negative effects of extreme pressure additives. In the FZG gear test, AMSOIL MCV achieved a perfect score with a “zero” wear rating." Key words here are "without the negative effects of extreme pressure additives" and "AMSOIL MCV achieved a perfect score with a “zero” wear rating.".

Amsoil also recommends their 20W-50 over their Severe Gear for the transmission for the twin cam. See link below. The "Best" choice for transmission is MCV (20w-50) and the second choice is SVT (Severe Gear 75W-110). I find this very interesting since MCV is $9.75 a quart and SVT is $13.15 a quart. Amsoil is recommending their less expensive oil over their more expensive gear oil.
AMSOIL - Harley-Davidson/AMSOIL Oil Chart
 
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Smitty,

Is this true, this is what Harley says,

"SYN3 is a full synthetic lubricant. It is the general practice in the oil industry that a true synthetic is formulated with Group IV PAO basestocks and is a true synthetic. SYN3 is formulated with PAO basestocks and is a "True-Synthetic"."

I also found this.

"What is the definition of synthetic lubricants?

Synthetic lubricants are manufactured in chemical plants by reacting components and are specifically designed to possess physical and performance characteristics that are superior to mineral oils. As a result, the molecular structure of synthetic lubricants can be precisely arranged to meet, and often exceed, manufacturers' criteria for high-performance equipment."

"Group II and Group III base stocks are enhanced mineral oils that are manufactured by a refining and extraction process which partially removes undesirable molecules that are present in the feed. In contrast, Group IV (PAO) base stocks are chemically synthesized and therefore, do not contain undesirable species."

Harley uses Group IV PAO so why isn't it a true synthetic?
 
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