I just switched to all automotive fluids and even a rear car tire. The ATF made so much sense to me to use because of the posts I've read about Harley using ATF in the primary back in the 70's and 80's. The bike's designs have not really changed that much. All I can see is that for marketing purposes, Harley threw some friction modifiers into their oils and called it Syn3 oil to have a one all oil and sell it at a premium price by calling it a miracle oil for everything. Also, if you do some reading on the Redline website, they do not recommend some of their gear oils for LSD differentials due to the lack of friction modifiers .Straight differentials, you use gear oil. Which is essentially what the motorcycle transmission is. All Gears with no synchros. That's why in a traditional manual transmission, you can't put gear oil. Because the synchros would not engage to slow down the oncoming gear. Hence the addition of friction modifiers. The cool thing about Harleys, they do not share a sump for all three components. So for the motor, we can use regular old motor oil, for the transmission regular old gear oil and for the primary (Clutches) ATF. Another thing about ATF, lets not forget that Automatic transmissions in addition of having clutch packs, they utilize roller bearings and chains. So to be concerned about premature wear on roller or ball bearings and chains would be a non issue here. I agree that by switching to ATF and to automotive fluids in general has made my bike run way better and not to mention, cut the cost of changing my "motorcycle" fluids by half. I have 40k miles on my bike and hoping to go 200k. Another concern that I've picked up from people is failing compensators. Compensators is an Achilles Heel on these bikes. So to attribute these failures solely on using ATF is basically wrong. There are replacement compensators on the market for this reason. I believe is '11 and before that have the bad design. I have a '12 but, I am looking at replacing this part in the near future anyways. Good luck to everyone out there attempting to make this change. As I say, "never be afraid to make a change. It may likely be for the better". Good luck guys

 

Corvettes for years use ATF in their transmissions and never require replacement. Good for the life of the vehicle. Many have tried it in their bikes successfully. It seems to me that it should be as good of a trans lubricant as H-D's Syn 20/50 which they use in the CVO's.

I have stayed with Bel Ray for my bikes from the 1K on over the past 12 years.

 

Jeep uses ATF in there tranfer case.

 

Dang, I started this thread almost 8 years ago!
I guess it's still of interest to people. I didn't own my current bike when I started this thread. Today, my current bike has over 20K and the bulk of those miles were with ATF in the primary. In fact, I still use it as an example of what a compensator is SUPPOSED to sound like when I hear a buddy who has one failing. I say, come here man, this is how your bike should sound when you cut it off. Not like yours. So I don't have 100k on her, but she's not the only bike I ride.

 

I just happened to stumble on this old thread and found one of my own posts regarding the use of automatic transmission fluid (ATF) in my primary case ! I have been using Mobil1 Synthetic ATF and change it periodically.

I was given a fatherly warning that in another 12k miles my compensator would be toast. Well, I now have closer to another 20k miles on the bike and that same compensator is doing just fine. So are the other parts of the primary assembly.

I've had H-D bikes for quite a while and currently have 3. Only my suped-up Super Glide is running the ATF so far but, boy, that set up with the Alto Carbonite clutch and stock light-pull clutch spring, works so well. Shifting is super slick and the clutch take-up zone is fantastic.

4WD Automotive transfer cases also have chain connected gears and many of them specify to use ATF.
.

 

Been running synthetic ATF in my primary 4ever n use it in my fork tubes also.

 

https://www.extremeterrain.com/jeep-...apacities.html

 

And the dead thread lives.....

Time for a 2022 update please sirs on your atf primary supplement...

 

Ha! Funny you bump it. I'm putting a Barnett Scorpion in my SGS and was doing some research. Barnett recomends ATF type F for a snappier grab and Dexron for. smoother grab, they specifically say no Formula Plus.

 

I was thinking similar I was thinking "yeah when the bike doesnt move any more in about a month then what..." Once those clutch fibers discs get soaked with it there could be all kinds of problems, and warranty wont cover it. friction coefficient is important.