What is the difference?
Grand HDF Member
Joined: Sep 2013
Posts: 3,820
Likes: 587
From: Michigan
Can't understand why everyone thinks the issue is full synthetic is "too slippery". It's NOT because Syn3 is full synthetic. It's because a lubricant formulated for engine use doesn't have the right friction modifier additives needed for wet clutch applications. Full, partial or non synthetic isn't the issue.
Road Warrior
Joined: Oct 2012
Posts: 1,451
Likes: 1
From: South Florida
A couple of years ago I had Amsoil in all three holes and had a simple Stage 1 in my '12 SG I had at the time. My clutch started to slip a little while getting a little throttle happy...it got worse quickly. The tech at the dealership finished it off on a test ride to see what's wrong.
The dealership told me that it wasn't a warranty claim because I had a synthetic motor oil in the primary. They told me that HD no longer recommended the use of a motor oil in the primary and that synthetic was even worse because they didn't allow enough friction under heavy torque loads. They said it was too slippery, whatever that means. They told me that it was recommended to use Formula+ or a primary oil with friction additives and that it was out on a recent Service Bulletin.
I argued with them for a bit until they agreed to split the cost (they installed for free) for a Sreaming Eagle clutch pak replacement. The only way I got them to split the cost was that I had just had them service the bike and they had checked the adjustment of the clutch and all was ok.
The dealership told me that it wasn't a warranty claim because I had a synthetic motor oil in the primary. They told me that HD no longer recommended the use of a motor oil in the primary and that synthetic was even worse because they didn't allow enough friction under heavy torque loads. They said it was too slippery, whatever that means. They told me that it was recommended to use Formula+ or a primary oil with friction additives and that it was out on a recent Service Bulletin.
I argued with them for a bit until they agreed to split the cost (they installed for free) for a Sreaming Eagle clutch pak replacement. The only way I got them to split the cost was that I had just had them service the bike and they had checked the adjustment of the clutch and all was ok.
Grand HDF Member
Joined: Sep 2013
Posts: 3,820
Likes: 587
From: Michigan
A couple of years ago I had Amsoil in all three holes and had a simple Stage 1 in my '12 SG I had at the time. My clutch started to slip a little while getting a little throttle happy...it got worse quickly. The tech at the dealership finished it off on a test ride to see what's wrong.
The dealership told me that it wasn't a warranty claim because I had a synthetic motor oil in the primary. They told me that HD no longer recommended the use of a motor oil in the primary and that synthetic was even worse because they didn't allow enough friction under heavy torque loads. They said it was too slippery, whatever that means. They told me that it was recommended to use Formula+ or a primary oil with friction additives and that it was out on a recent Service Bulletin.
I argued with them for a bit until they agreed to split the cost (they installed for free) for a Sreaming Eagle clutch pak replacement. The only way I got them to split the cost was that I had just had them service the bike and they had checked the adjustment of the clutch and all was ok.
The dealership told me that it wasn't a warranty claim because I had a synthetic motor oil in the primary. They told me that HD no longer recommended the use of a motor oil in the primary and that synthetic was even worse because they didn't allow enough friction under heavy torque loads. They said it was too slippery, whatever that means. They told me that it was recommended to use Formula+ or a primary oil with friction additives and that it was out on a recent Service Bulletin.
I argued with them for a bit until they agreed to split the cost (they installed for free) for a Sreaming Eagle clutch pak replacement. The only way I got them to split the cost was that I had just had them service the bike and they had checked the adjustment of the clutch and all was ok.
Cruiser
Joined: Aug 2014
Posts: 169
Likes: 30
From: Gulf Harbors/Woodlands, FL
I did my own 5k service on my 2014 SGS, and changed out the primary and trans (even though it's not on the maintenance schedule until 10k), and put in Syn3 in all 3 holes. At 6200 miles, I couldn't believe the rattle/noise from the primary. So removed it and replaced with good old (I believe it's 40wt) Formula +. Normal primary noise again, seems to shift much happier too. Just my 2c
Seasoned HDF Member
Joined: Jan 2005
Posts: 5,857
Likes: 2,506
From: Lake Orion, MI
OK guys - I have to let you know that I am a motorcycle rider - don't do any sort of repair work and know little or nothing about these sorts of things. Ask me a financial question - and I cna provide a reasonable response.
Now having said this, I depend on my dealer to do the right thing to keep my bike running in top condition. When the service work is required, I take it to the dealership. In fact, I just picked the bike up on Friday - had a 15,000 checkup.
From the receipt, the dealer used Syn3 -and since i don't see any other oil charges, I have to imagine that is in all 3 holes.
So this now leads to my question. If I end up having a clutch problem - and the dealer says it is not a warranty issue because of the Syn3 oil, how in the would would they be able to support this if they are the ones that installed the product?
One last question - in total, how many quarts of oil does it take to fill all three holes?
Now having said this, I depend on my dealer to do the right thing to keep my bike running in top condition. When the service work is required, I take it to the dealership. In fact, I just picked the bike up on Friday - had a 15,000 checkup.
From the receipt, the dealer used Syn3 -and since i don't see any other oil charges, I have to imagine that is in all 3 holes.
So this now leads to my question. If I end up having a clutch problem - and the dealer says it is not a warranty issue because of the Syn3 oil, how in the would would they be able to support this if they are the ones that installed the product?
One last question - in total, how many quarts of oil does it take to fill all three holes?
Stellar HDF Member
Joined: Dec 2013
Posts: 2,198
Likes: 282
From: Long Island NY
Usually 3 qts. fills the engine although most dealers charge for 4 qts., 1 qt. into the transmission and 38 ozs. (1 qt., 6 ozs.) in the primary. So an honest dealer would charge you for 6 qts.
Tourer
Joined: Jun 2015
Posts: 301
Likes: 2
From: 46835
Again, more lay-people using the full synthetic is too slippery argument. And it's total BS! The real truth is the lack of friction modifying additives that wet clutch packs require but motors don't. No lubricant can be all things for all applications without compromising performance for some of those applications.
The only caveat is that many street bikes will never approach the sheer forces required to make this an issue. I ran Mobil 1 and Mobil 1 MC in a 185hp track bike and never had issues with either one.. Engine, trans, clutch all share the oil...
In my old guy skepticism, I wonder if it might not be a ploy to simply make some oils cost more?
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Outstanding HDF Member
Joined: Sep 2006
Posts: 2,878
Likes: 164
From: Northern California
Just FYI; syn3 is not a full synthetic oil. It's a blend.
Just switched to Mobil 1 V-Twin in my motor, Spectro full Syn primary oil in the primary and Spectro HD 6 speed full Syn transmission fluid in the trany. As recommend by Baker. I trust Baker.
Just switched to Mobil 1 V-Twin in my motor, Spectro full Syn primary oil in the primary and Spectro HD 6 speed full Syn transmission fluid in the trany. As recommend by Baker. I trust Baker.