Thanks for all the quick replies... I probably should have been clearer about one point: He wasn't trying to say use only Amsoil in your primary, he was saying don't use synthetic 'motor' oil of any kind in it. I've put about 200 miles on mine since putting Mobil 1 20W50 Vtwin in it, and I've had no problems, either.

 

Hi Mike,

I too, have been using Amsoil in all three holes in two different baggers. As I cannot speak for the other oils, I know that Amsoil will not cause any clutch slippage whatsoever! Many people have asked Amsoil about this in the past, and they have explained this on their website: www.amsoil.com

Below is an excerpt from the website:

Provides Excellent Wet Clutch Performance
AMSOIL MCF contains no friction modifiers and promotes smooth shifting and positive clutch engagement. AMSOIL MCF controls heat and prevents slippage and glazing, and its high TBN resists acids that can degrade clutch material, helping improve clutch life.

 

I would not use any Amsoil product but that's just because I do not like their marketing.

I use Mobil 1 V-Twin 20W-50 in the crankcase, Mobil 1 75W-90 Gear Lube in the trans, and HD Primary in the Primary because I like the "feel" it gives the clutch.



Your mileage may vary, but really this has been pretty much beaten into the ground and a use of the search button will turn up more information that you care to read.

 

Syn oil in the clutch, even with friction modifiers can cause clutch slipage, however it takes extreme power like found on high output crotch rockets. Harleys unless really built will not have problems.

 

Hdmikeshirley: I agree with what he told you. I am a synthetic fan for many years (Redline, Amsoil, Mobil 1, but in the primary I use HD Forumla+.

Hogback

 

ATF in the primary - Redline in the other 2.

 

it is true... clutches hold better with fossil oil....rotella T 15/40 is a great choice...but yall believe what ya want

 

It is true that synthetics in the primary will cause slippage but it is on bikes with some miles on the clutch packsand above average torque too. The new SE bikes do come with it in all three but remember, these are new clutches and still have a good grip and harley sells syn 3 now. An oil without friction modifyers like stated above will work best and give you better hookup on the clutch than synthetics will, even the formula+ will work better than synthetics.

 

I use Mobil 1 synthetic ATF in the primary, no problems of any kind! '04 RK Custom.

 

I agree with this. The primary does not require a high-tech lubricant, but just enough to cool the clutch plates and lubricate the chain. Anything over $3 in the primary is overkill, IMO, and although synthetic is the right choice in the engine and tranny, I would stay way from it in the primary.