Using ATF in the primary

[willy115]

Hi all. I've heard people mention folks using Dexron III rated ATF so I thought I'd give it a try. Man what a difference. Bike shifted easier immediately. Also made less of a clunk shifting into gear from neutral. I'm also able to find neutral easier. Is there a down side to using ATF? Any input would be appreciated.

[Baggger]

Welcome to the forums mate.

I've run a few kevlar Barnett clutches over the years and they actually recommend ATF. Absolutely nothing wrong with using it, no trade-off. Just change it regularly but you should be doing that with all fluids anyway 😉

[HDNZ]

Been using it off and on for years, no issues at all

[Tooly]

A lot of clutch makers suggest soaking the friction plates in ATF before installing them. It's made for automatic transmissions which just like a Harley primary are full of clutch packs and bearings. You'll be fine 👌

[willy115]

Nice one thanks lads

[Roberto88]

Glad it’s working for you! ATF (Dexron III/Mercon) is thinner than gear oil, so it can smooth shifts and reduce clutch drag great for some bikes. Downsides? It might not protect as well under extreme heat or heavy load, and some say it breaks down faster. If your bike’s manual allows it (some Harleys/Kawasakis do), no big deal. Just change it a bit sooner (like every 2-3k miles). If not, stick with manufacturer specs. 

[Benporaken]

There's plenty of discussions on this on the net. The biggest thing is some oils eat brass (I think it is), and Harleys have this in the primary drive area. There's a couple of gear oils that work, but otherwise best to stick with something made for the job. 
Maxima mineral primary oil is so cheap I don't know why you'd use anything else.

[willy115]

There's plenty of discussions on this on the net. The biggest thing is some oils eat brass (I think it is), and Harleys have this in the primary drive area. There's a couple of gear oils that work, but otherwise best to stick with something made for the job. 
Maxima mineral primary oil is so cheap I don't know why you'd use anything else.

Haven't heard of this one thanks I'll check it out

[HDNZ]

No problem with modern ATF eating or affecting brass fyi