I run Syn 3 in all 3 spots..And have not one problem. Actually shifting clunk quited down. Even the guys at my local dealers (yes 2 seperate ones) says its OK.

Maybe the reason they don't put it in their Sceamen' bikes is because it's pricey....You know if HD can save a little coin they're gonna do it.

This is actually the first time i've heard of not putting Syn3 in all 3. Isn't this the reason they named it Syn3? Because it's ok to use in all 3.

 

was at my dealer a couple days ago and I noticed a new screamin eagle and it had a sticker on the case that said "To be removed ONLY by the owner, SYN3 oil.."

 

Well there you go....they do come with Syn3.....

 

Interesting, my 2010 Street Glide came from the MOCO with Syn 3 in all three holes. So far it has been working great for me.

 

Um....my 2010 FLSTSE came with SYN3 in all three hole and the Owners Manual mentions in many loations to use SYN3 when replaing the fluids.

 

Amsoil 20w-50 in motor, Amsoil 75w-90 gear lube in Tranny, Amsoil 10w-40 in primary. Not saying this is the right or wrong combo, just what I use. Probably just go to 20w-50 in everything next fluid change so I just have to keep one thing on hand.

 

What number is that service bulletin? I asked my dealer and they never heard of it. And they have always been very honest very honest and upfront with me. I use syn 3 in all holes and no problems.

 

There have been so many oil threads it's stupid. I'm probably stupid for posting this, and others who are sure they know more than me, will contradict me. That said, Harley recommends a GL5 rated oil for the '07 and later Cruise drive 6 speed. That tranny was used in the '06 Dynas too, but this ain't the Dyna Forum. Because of the helical gears it requires a different lube than previous trannys. Harley sells a lube specifically for primaries and transmissions in big twins. It's called Formula +. My '07 service manual says "use only Formula +." It does not mention Syn 3. Still people continue to tell you use Syn 3 in all three holes. Will it work? Sure, probably for quite a while. Is it the best choice to protect your investment? I doubt it. It's just convienent for guys who want to do their own changes and might get confused about which hole is for the engine, which is for the primary etc. I don't give a damn what you put in your tranny. Me? I won't put Syn 3 motor oil in my gearbox. Why? There are gear lubes available!

 

Agreed, Northside. Formula+ is $9, just like the Mobil1 Syn3. So why take the chance of making your tranny or chaincase not last as long??? And at least for us Fatboy owners, they both take 32oz, which means grab 2 bottles of that and a couple of O-rings at the HD shop for the average fluid change.

 

I use Redline 20w50 in all three holes. Works great, smooth shifting.