Syn 3 or no?
Road Master
Joined: Mar 2013
Posts: 1,151
Likes: 14
From: Seattle
As you can see, there is probably no right answer. On a warranty repair, the shop put Syn 3 in my primary and I started having a grabby clutch so I drained it after a week and replaced with my usual Rotella T 15-40. Engine gets Mobil 1 15-50 synthetic from Walmart ($25 for 5 quarts). Transmission gets Redline Heavy - the pink stuff. Pick whatever combination makes you feel good and stick with it.
Road Warrior
Joined: Oct 2007
Posts: 1,983
Likes: 165
From: North, Fl
Find a combo that works for you and stick with the recommended intervals.
Cruiser
Joined: Sep 2012
Posts: 203
Likes: 0
From: Livingston, La.
I have to chuckle a little each time I read where a rider has been taken in by the MOCO and it's BS about using nothing but HD products. Have you ever seen a HD refinery?Have you ever seen or been to a Harley Davidson Service Station for fuel and fluids? Have you ever looked into where the oil comes from. The MOCO has had one company bottle the oil for it for a while and from what I'm told they had to go to another supplier. The oil you are using is not produced, refined or from any oil well owned by HD. While the oil co. is required to meet certain standards, the oil is no better and actually fails in some head to head comparisons. Take Care Fairshake
Road Captain
Joined: Aug 2013
Posts: 519
Likes: 83
From: NC
My dealer actually recommended against using Syn 3 in the primary and transmission despite what Harley says. I can't recall exactly what all the technical stuff was that prompted that recommendation, but I figured if a dealer is actually making a recommendation against a Harley product then they must have a good reason. The dealer recommended using either a specific fluid in each hole (like Redline) or Formula +.
Road Captain
Joined: Sep 2011
Posts: 541
Likes: 3
From: Sherwood Park AB Canada
Any of the synthetic oils certified for use in V Twins will do the trick in all 3 holes just fine and, as has been already said, it just a matter of preference. That said, I never saw the logic in putting a motor oil in a manual trans so I don't.
I run Amsoil 20/50 in the engine and primary and change it every 5k miles and Amsoil Severe Gear 75/140 in the trans and change it, well, never. If its good enough for heavy duty differentials and transmissions for 100,000 miles or more, it good enough for my little 6 speed tranny for at least that long.
I run Amsoil 20/50 in the engine and primary and change it every 5k miles and Amsoil Severe Gear 75/140 in the trans and change it, well, never. If its good enough for heavy duty differentials and transmissions for 100,000 miles or more, it good enough for my little 6 speed tranny for at least that long.
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Road Warrior
Joined: Apr 2011
Posts: 1,365
Likes: 9
From: Greensboro, NC
What is so special about an H-D transmission that it needs the oil changed so often?
Cruiser
Joined: Aug 2013
Posts: 173
Likes: 12
From: South Hadley MA
no one flaming the OP for starting a dreaded " oil thread " ...LOL.... but since he started it I have a question concerning the crankcase oil ONLY as I use REDLINE w/shockproof in my tranny and their primary oil in said primary....anyways,I have been running MOBIL 1 20-50 V-twin in the crank but can get 15-50 in 5 qt. jugs at Wal-Mart MUCH cheaper. Does anyone know of any differences ,besides the obvious winter weight,like additives or such,or any reason not to run this much cheaper oil?