What have you found to be the best fluid for your primary?

 

I have a 1984 FXEF with the factory diaphragm clutch and isolated primary. I use Valvoline 10W40 in my primary.

A rule of thumb is use the lightest oil that you can in the primary and the heaviest that you can in the transmission for smoother shifts, long life, etc. Many peoiple use ATF in their primaries.

 

some as said above use ATF - some use 10 / 40 motor oil for motorcycles not car oil, as it does not have an additive package for clutch discs

some use sporster trans fluid as its additive package is for chains gears and clutches - some use evo primary fluid and we had also used 15 / 50 Mobil 1 syn motor oil as well as

NOW mobil 1 syn ATF < now that is for me the best one it has everything you could want and more - jz

 

--- http://www.cruisercustomizing.com/pr...FY3m7AodPzgAKg --

 

10w40 or 20w50 motor oil, Shell Rotella T 15w40 (can`t beat the price of this stuff).
Just enough in there to touch the starter ring gear, with the bike upright.

 

My new oil of choice: Spectro Heavy Duty Primary Chaincase oil.

Just started using their Spectro Heavy Duty Gear Gaurd oil in the tranny. It's 85 - 140 and it's dyed red so when a leak in that area occurs you can identify the source.

Your going to get a whole lot of different answers and some may even give you a hard time because this question gets asked all the time, and there is a few hundred discussion you can find if you just use the forum's search.

If anything your going to have too many suggestions to know what you really want.

 

You're not lying there is so much info/debate on this topic. Thanks for the info though!