2013 FLSTC
I recently changed my primary fluid to Dexron III and want to go back to Formula +. Do I need to remove the cover and wash all the ATF out. Or, can I drain the ATF and fill with F+. Just wondering how well they would mix with the few ounces of ATF residual.

 

Get some Rotella T4 15-40. Its cheap. Drain the ATF and put in the T4. Ride for 20 minutes. Drain and put in fresh T4. Done. You may like it. It's great for finding neutral too. $16 a gallon at any box auto parts store.

 

Thanks for the reply.

 

I wouldn't bother with flushing! Just drain the old oil and replace with your new one.

 

Thank you.

 

I would not worry about it.

 

I've gone back and forth between ATF and Formula+ a couple of times without flushing. Zero problems so far through 45K miles. I don't think flushing is necessary.

 

i have used the HD primary oil, atf type f, 10w30 motor oil, 10w40 motor oil, 20w50 harley dino oil, and 20w50 generic racing oil in my primary. over 100k miles and still running the OE clutch plates and primary chain. never rinsed the primary, i just used whatever i had laying around the garage.

 

Thank you.

 

Any automotive engine or trans oil, or any mixture of the two. But whatever you do, don't use what Harley specifies....