Primary Oil Question
Seasoned HDF Member
Joined: Nov 2010
Posts: 17,548
Likes: 7,207
From: Oxford, Nc
Of course the more expensive oils work fine in the primary...They're severe overkill so why wouldn't they?
10W-40 motor oil from the grocery store ( $2.37 Qt.) every 5,000 miles for the last 12 years and 102,000 miles and NOTHING in my primary has ever been changed out, not even the clutch plates.
But hey, if the more expensive stuff makes the owner feel better, more power to ya'.
10W-40 motor oil from the grocery store ( $2.37 Qt.) every 5,000 miles for the last 12 years and 102,000 miles and NOTHING in my primary has ever been changed out, not even the clutch plates.
But hey, if the more expensive stuff makes the owner feel better, more power to ya'.
Ultimate HDF Member
Joined: Jan 2008
Posts: 7,476
Likes: 5
From: Republic of Texas
No severe gear in primary. I run semi syn Belray in my transmissions. Like stated above. Less clunk, plus transmissions haven't really changed in hds except added gears. We ran gear lube in the old days in the transmissions and I liked it. I just use hd primary oil out of convenience in my primary but Mobil1 V-Twin in my oil tank. Another oil thread---it is winter.
Outstanding HDF Member
Joined: Jan 2009
Posts: 2,145
Likes: 2
From: Ontario East
Not enough to bother my wallet.
Stellar HDF Member
Joined: Feb 2010
Posts: 3,400
Likes: 268
From: Southern California
I think the logic is that the additive package used in oils made for use in engines and transmissions can affect the coefficient of friction if used in a wet clutch application. To what extent this actually impacts the actual performance and the life of the wet clutch in a Harley . . . I do not know. As others have posted I simply run the recommended stuff as the few dollars difference isn't worth a minutes worry. I run Mobil1 20W-50 for Motorcycles in all 3 Holes, and occasionally the MoCo stuff if it's on sale. I do know that we used to use (I'm dating myself here) Ford ATF in GM Automatics as a cheap "Shift Kit" due to the differences in the coefficient of friction between "F" type ATF and Dextron II. The again, we also used a cup of DOT-3 Brake Fluid to seal the leaks on Transmissions in those days. Geez, the $h!t we used to get away with.
Last edited by Bluehighways; Jan 23, 2012 at 11:54 PM.
Seasoned HDF Member
Joined: Oct 2010
Posts: 12,234
Likes: 7,814
From: Along the shoreline in SW FL
Way overkill IMO. Granted...unless you're maintaining a fleet of > 100 bikes...it's not like it will make a huge dent in your wallet...and hey, it's your wallet, your money.
Primary doesn't need anything fancy..hell, you could **** in it or pour beer in there and it'll be fine. Just needs to be a little wet.
Primary doesn't need anything fancy..hell, you could **** in it or pour beer in there and it'll be fine. Just needs to be a little wet.
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I have the same Amsoil in my primary as well as engine & trans.
In both bikes.
And the two previous bikes we've owned.
NEVER a single problem.
Hell, you think Amsoil would recommend and even guarantee it if it didn't work?
I know a lot of people are all "Oh, the clutch will slip with slippery synthetic oil like that!"
I've been hard on the throttle for over 10K miles on my SG, even a couple hole-shots & "from a dig" take offs. My clutch has never slipped once.
In both bikes.
And the two previous bikes we've owned.
NEVER a single problem.
Hell, you think Amsoil would recommend and even guarantee it if it didn't work?
I know a lot of people are all "Oh, the clutch will slip with slippery synthetic oil like that!"
I've been hard on the throttle for over 10K miles on my SG, even a couple hole-shots & "from a dig" take offs. My clutch has never slipped once.
Outstanding HDF Member
Joined: Jul 2011
Posts: 2,052
Likes: 6
From: North London, UK
I use Motul 20W50 fully synthetic in the engine and primary and Redline 80w with Shockproof in the trans. Bike runs like a top - no clutch slippage and the shift is very smooth (for a Harley). The inside of my thighs tells me the bike runs cooler too...