You might in colder weather.

 

I personally use Redline MTL
But people are quick to discredit ATF because it's only for A/Ts. Most manufacturers use ATF in their transfer cases, and guess what's in those? A giant CHAIN, and GEARS??? No way... I'd venture to say the transfer case in my truck is under a bit more stress than an HD.

 

Many off-roaders use ATF in their MX and single tracks bikes transmissions. In my GG trials bike, ATF type F is the factory-recommended trans oil because it holds up better than regular oils with the sheer force of the gears. ATF is a very tough resilient oil to wear and heat in those applications, just like a car's AT.


My old TC has had the HD 20/50 in it and Hypoid gear oil, never did the ATF deal, no particular reason, just haven't.

 

running Formula+ and it works well. Tried other things, but, bike runs well w/ it (2008 Ultra)

https://www.harley-davidson.com/us/e...ant/p/62600004

 

One of aftermarket clutch manufacturers warns against using F+ with their Kevlar clutches as they've had numerous reports of it causing slipping.
I've never run it so take that for what you will.
The one thing they all agree on tho is type F ATF.

 

Come on guys; winter is over and this is way past boring.

 

Go back in your hole you crawled out of...There will be six more weeks of winter...!

Phil

 

If your aunt had *****, she might be your uncle.

 

HD is recommending the 80W140 for bikes back to the 90's

 

In the primary???