so im thinkin about putting honda hp racing transmission oil in my primary on my 2008 fat bob. stuff is really good. it has anti friction and anti slip properties and also anti foaming/shearing properties. stuff is red and looks just like atf auto transmission oil. what do u guys think? i put lucas 75/90 gear oil in trans and man what a diffrence in shifting. hd oil must be crap for it to make that much of a diffrence.

 

Do not put anything in the primary that doesn't say JASO on the label somewhere.

 

how come. what is jaso

 

I run the CHEAPEST 10W-40 or 20W-50 dino oil I can find for my 5,000 mile services.

($2.37 a quart the last time.)

The bike is now 12 years old and has 108,400 miles on it.

Everything in the primary is still the original part. Even the clutch plates.

It's my daily commuter. So much for wasting your money.

 

i thought oil with jaso was for engine oil. isnt the primary a sealed seperate compartment with the clutch that has nothing to do with the oil that runs thru the engine internals? dont u want something that will not slip clutch plates?

 

I use Type F ATF.

 

what weight is type f atf. i put honda hp transmission fluid in primary. this stuff has anti slip ingredients for clutch plates in a 2 stroke wet clutch racing transmission. its 80/85 weight which is equivalent to 10w 40 or 10w 50 motor oil. this stuff is red and i could swear its at fluid. this oil can take a beating since a 2 stroke clutch gets much hotter and abused than any harley clutch since a 2 stroke clutch is being slipped out of corners constantly. any imput from anyone would be helpful. ive been racing mx for 35 years but this is my first harley. its a 2008 fat bob. im guessing that the primary is a completely separate compartment from the transmission and top end.

 

Barnett recommends running Type F ATF in the Harley primary. I always used 10W-30 M/C wet clutch oil, but after installing a Barnett carbon fiber extra plate clutch kit, I added ATF, and I must admit My clutch action feels awesome. I ran Barnett's back in the 80's and those clutches used to be kinda grabby back then, not the case now. I'm very happy, smooth as silk , yet grabs SOLID when you hammer down !

 

JASO means it won't make the clutch slip and contains no friction modifiers.
JASO spec is required for shared sump bikes,because of the clutch. Otherwise you could use any oil you want.
And the advice above about any 10w-40 is not very good advice.
Ever since the oil companies went with the new SN spec they had to reduce zddp in engine oils due to catalytic convertor and shortened life. Since they reduced the zddp they have to add more friction modifiers to compensate. So yes even 10w-40 oils now contain them.
Find an oil that says JASO ma2. Rotella is what I use and have for years without any issues.
JASO buddy.

 

Shredding Rubber is right on. Oil manufacturers had to get the Zinc out so they replaced it with Moly. Wet clutch fiber discs do not like Moly. Use an oil made for motorcycles with wet clutches, steer clear of automotive oils and you will be fine. Diesel truck oils as Rotella is an excellent choice also.