No, it was developed and used in airplanes during WWII. The Germans seemed far ahead of everyone else, I think their driver was their lack of a solid supply of regular oil.

If your Harley is getting hot enough to fry a good conventional oil the motor is done, you are talking about over 400 degree flash point. I would assume the primary is not getting as hot as the engine being that (hopefully) there is no combustion happening there.

I can't imagine there would be any harm that would come from using synthetic in the primary, I just cannot imagine a need to or an advantage that might come from it.

 

I live these threads. Worth reading just to look at all the geniuses. I'm just a DAR (dumb *** redneck for those who aren't). I love how everyone talks trash to everyone. It's like who's pecker is bigger than the next. Quite frankly, mine may be short but it's girthy.

 

Gee! Does your dealer know that they ship all CVO's with syn 3 in all three holes for many years now. Also in Vrod's.

No, there is no problem with any Syn oil in all three. Your bike do what you want.

N0! No! No! Syn oil will NOT cause a clutch to slip or a stator to burn up.

The only oil to avoid in a clutch is car oil rated "energy conserving" as it has modifiers that may absorb into clutch material and slip.

Many folks involved with HD's at the dealer and owners are at times totally clueless about oil. Virtually all metrics run 10W 30 motor oil in their bikes which have wet clutches and the motor, transmission and clutch share the one pool of oil. Good enough for them good enough for me. My Honda VTX1800 and Rune did as all the other Honda's, Suzuki's, Yamaha's and Kawasaki't did.

When people say the "dealer told me" they should be more specific. Was it the service writer, the mechanic, the salesman, the clothes sales lady? We all know it was not the the owner (dealer) as he was at the bank or something. Could have been the custodian.

 

In my 2012 FLHX owners manual SYN 3 in all holes is still recomended!!

 

Being a newbie to HD I have a better understanding of the three holes.
Engine, transmission and primary.
What is the primary?

Put engine oil in your engine, primary fluid in the primary, transmission fluid in transmission. That sound logical, being a logical kind of a guy that I am.

 

I forget what they claim, but Redline has addressed the stator issue with their primary fluid. It's good stuff, as is their oil and pretty pink tranny fluid!

 

The "primary" chain and chaincase are that big chrome thing on the left side of the bike. There's a chain that runs (drives)from the crankshaft to the transmission. in the day it was the first (primary) chain, then the second chain ran from the transmission to the rear wheel, it's a belt now.

Back to this thread, guys, I've been running Syn 3 in all three hole for eighty thousand miles with no ill effects. I don't get all of the "Syn 3 is crap" sentiment on this forum.

 

For me, the fact that CVO'S come standard with SYN 3 in all 3 holes from the factory and coupled with Mobil's recommendation to use their V Twin Mobil 1 in all 3 holes are good enough for me. I look at it this way, between the 2 if something was to happen, they have a lot more money than I have to research the effectiveness. Plus Mobil wouldn't recommend it if they didn't feel it was able to withstand the shearing.

I have used Mobil 1 in both my Goldwing and my Street Gilde without an issue. Plus in both machines it has drastically improved the shifting qualities of each one. Much quieter and smoother. In the SG, neutral is absolutely easier to find. We all have opinions and march to different drummers so feel free to pick your poison. For me it's Mobil 1 until further notice. (BTW, the dealer who recommended against it is an idiot as it is their personnal opinion is all.)

 

Maybe the cheap insulation on the wires on those Chinese stators melts off from some chemical on syn oil?

 

I'm sorry. I don't mean to call you out or be rude, but, what does a reference to automobile automatic transmission fluid have to do with the OP's question? Are you even remotely suggesting that Mobil 1 ATF has any place in a Harley? If so, please explain your thoughts.