I recently restored a 76 FXE. I'm now running a sealed system for engine and primary. I'm running Type-F tranny fluid in my primary. It's performing great. No drag at lights, smoother shifts. Remember, transmissions have chains and disc's. And if your primary leaks, you'll know by the color. LOL

 

Good topic! I copied this from another forum, there are other types of ATF that are even better:

Type F or (Ford) fluid was developed for and used in Ford automatic transmissions back when the clutch discs were made of sintered bronze or asbestos and there were no bearings used. All parts were supported by bronze bushings and thrust washers. It is essentially 20wt hydraulic oil (pure mineral oil) with a red dye and that's it. It is commonly sold as Racing ATF under brands such as B&M Trick Shift because it provides the quickest lockup of the clutch packs (hardest shift). It has no place in 99.9 percent of modern applications unless you're just looking for neck snapping shifts (or in the case of motorcycles used for drag racing where quick and harsh clutch engagement is the primary goal and you're gonna change it very often.

Dexron II and III are the most commonly used fluids with the only difference being additives in Dexron III to make it more compatible with the electronics used in modern transmissions.
They both have an additive package that includes friction modifiers for smoother clutch engagement, oxidation control, viscosity stabilizers, corrosion inhibitors and proper lubrication of bearings and bushings of all types. Since the advent of gerotor pumps and better friction materials such as Kevlar and Aramid, Dexron II or III has even replaced the use of Type F for racing use by most transmission builders.
Dexron III is commonly used in many automotive manual transmissions and is probably used in more transfer cases of 4WD vehicles than any other fluid.

ATF+3 uses higher quality base oils with the highest content of friction modifiers to prevent torque converter shudder. It lubricates a bit better than Dexron III but can also cause slow clutch engagement (slipping). If you ride easy and your primary goal is smooth clutch engagement then this is the fluid to use in your primary if you're gonna run ATF.

Synthetic ATF comes in many formulations but the most common is Dexron III. It has the same properties of clutch engagement as Dexron III with some advantages.
The main advantage of synthetic fluid is its ability to resist thermal breakdown. If you ride in extreme heat or just want to extend your primary fluid change intervals then this is probably your fluid.

 

How much did it take to "fill"?

 

I've used Ford Type F ATF for decades with no problems.
I'm running a Barnett Scorpion clutch and Barnett recommends Type F.
I'm always interested in an improvement for my bike but I don't see any advantage in changing. If Type F ever becomes hard to find I'll be trying other lubricants with Barnett's input to guide me.
In the years prior to the Scorpion clutch I have tried MANY different clutches, all with Type F and some worked better than others. I wonder if one of the other ATF's out there would have improved their function...too late now!

 

the only difference between the two in a harley is in the clutch ingage - type F grips better on take off - if you prefer a slide than dextron is your oil thats it

the original 1960s / 70s type F was as stated above But today is has an additive package in it as its primary use today is racing automatics like the powerglide, and they have bearing in them replacing the brass bushing in some locations so both F and dex #3will work in the primary -

in the sportys we use syn mobil 1 dextron 3

 

Level the bike and pour in just enough to touch the bottom of the clutch shell , comes out to about 1/3 to 1/2 qt max , way I've been doing them for the last 35 yrs .

 

so are you saying joe dextron II and III are good to use in the primary hmm if so I just serviced my ford vans tranny have some fluid left over I know what I can do with it now

 

I won't take claim of any real knowledge, just copying something that I found.

But to respond to the above, if Barnett says use Type F, then use Type F, they know what's best for their clutch. It makes sense there are additives in it now, but it sounds like it's more for racing applications regardless. That's follows what johnjzjz has experienced, and many others, I'm sure.

Skully, not sure if it's wise to mix, but for a drain and fill it'll probably be OK. But if it were me I"d make sure all the other oil was cleaned out.

Here's a question: If I isolate my primary, do I have to get new friction plates, or just clean the motor oil off with mineral spirits and rough up?
Thanks! Joe

 

if you bought just one quart of ATF you have 2 changes - soo what we do is tell the customer to drive it with the new oil for a week than change it again -

no real need to take it apart -- if other issues are going on than sure take it all apart -- if at any time you need a new clutch the best one for ATF is the red ALTO discs - as alto red ( ALTO is the company name make sure its an alto clutch not a china copy ) is what is used in racing automatics today, and a some years back when they Alto seen harleys using ATF they started making discs for them -- jz