ATF in primary
Elite HDF Member
Joined: Sep 2012
Posts: 3,791
Likes: 57
From: N Texas
You can see the missing metal where the spokes of the compensating sprocket engage the sliding cam. The sliding cam is showing wear and the sproket retainer is getting scratches where it fits inside the compensating sprocket. I had cleaned the 3 pieces up before the pic but they had that red rusty burnt up residue all around the inside of the compensating sprocket and the same scratched up areas of the sprocket retainer.
Road Captain
Joined: Apr 2013
Posts: 583
Likes: 4
From: australia
atf in your primary is great, think off your car auto , they have gears, wet clutch plates, the same as your bike. its friction modifiers that stuff up clutch plates...read your owners manual Harley recommends diesel oil in your crank case ,, very high in detergent, the best oil for primary is around 30 weight..
Extreme HDF Member
Joined: Feb 2015
Posts: 10,907
Likes: 8,758
From: Galt's Gulch - MI
atf in your primary is great, think off your car auto , they have gears, wet clutch plates, the same as your bike. its friction modifiers that stuff up clutch plates...read your owners manual Harley recommends diesel oil in your crank case ,, very high in detergent, the best oil for primary is around 30 weight..
Synthetics can be used in the primary if you want to do so, just be sure the 'energy conserving' rating isn't on the label, if you use a synthetic that's JASO-MA rated and you won't have any clutch slipping issues.
Road Master
Joined: Jul 2013
Posts: 946
Likes: 29
From: my house
Only benefit I have heard of from using ATF was flawless clutch operation. That's stuff is like water compared to other primary fluids, so I would think it be a bit noisier if anything.
If you switch your tans fluid to Spector or Redline (something better than the factory stuff) much of those noises/harshness will be eliminated. I noticed a bigger difference when I switch out my trans fluid than the primary.
If you switch your tans fluid to Spector or Redline (something better than the factory stuff) much of those noises/harshness will be eliminated. I noticed a bigger difference when I switch out my trans fluid than the primary.
Seasoned HDF Member
Joined: Mar 2010
Posts: 38,593
Likes: 6,435
From: Honah Lee
atf in your primary is great, think off your car auto , they have gears, wet clutch plates, the same as your bike. its friction modifiers that stuff up clutch plates...read your owners manual Harley recommends diesel oil in your crank case ,, very high in detergent, the best oil for primary is around 30 weight..
Last edited by Jackie Paper; Sep 14, 2018 at 11:10 AM.
Cruiser
Joined: Feb 2015
Posts: 196
Likes: 0
From: Show Me State
i switched to ATF in my primary about 2k miles ago. Maybe my scenario is not typical, but it made a tremendous difference in the ease of shifting.
This winter, I bought a 2010 Ultra with 2900 miles on it, and the bike would creep every time I would come to a stop, like the clutch was still grabbing slightly. So I adjusted the clutch, no improvement. Readjusted the clutch 2 more times, no improvement. So I drained the Formula + out of the primary and went to synthetic 20W50, same as my crank oil. Maybe a very slight improvement, but not enough to know for sure that there was a difference.
So after reading about 100 posts/articles/arguments about what to use in the primary, why use friction modifiers and why not, why not stick with Formula +, why, why, why, etc.....
I decided to give synthetic ATF a try. It worked fantastic, the shifter "clicks" into gear now with very little shift lever pressure compared to almost stomping on the lever previously to engage a gear, and the creep has completely gone away as well. I couldn't be happier with the change. Finding Neutral is like it should be and not a 1 minute endeavor moving the bike back and forth. I have not noticed any audible difference coming from the primary as some mentioned a whining noise when using ATF, I can't tell a difference in noise.
I have no idea as to why this worked so well for me, or what my actual problem is with using the conventional primary fluids, but for now I am sticking with the ATF. I may try to use Formula + again at my next oil change and see if it goes back to the hard shifting and creeping, and if it does, then I will stay with the synthetic ATF for good.
This winter, I bought a 2010 Ultra with 2900 miles on it, and the bike would creep every time I would come to a stop, like the clutch was still grabbing slightly. So I adjusted the clutch, no improvement. Readjusted the clutch 2 more times, no improvement. So I drained the Formula + out of the primary and went to synthetic 20W50, same as my crank oil. Maybe a very slight improvement, but not enough to know for sure that there was a difference.
So after reading about 100 posts/articles/arguments about what to use in the primary, why use friction modifiers and why not, why not stick with Formula +, why, why, why, etc.....
I decided to give synthetic ATF a try. It worked fantastic, the shifter "clicks" into gear now with very little shift lever pressure compared to almost stomping on the lever previously to engage a gear, and the creep has completely gone away as well. I couldn't be happier with the change. Finding Neutral is like it should be and not a 1 minute endeavor moving the bike back and forth. I have not noticed any audible difference coming from the primary as some mentioned a whining noise when using ATF, I can't tell a difference in noise.
I have no idea as to why this worked so well for me, or what my actual problem is with using the conventional primary fluids, but for now I am sticking with the ATF. I may try to use Formula + again at my next oil change and see if it goes back to the hard shifting and creeping, and if it does, then I will stay with the synthetic ATF for good.
Seasoned HDF Member
Joined: Mar 2010
Posts: 38,593
Likes: 6,435
From: Honah Lee
You are probably putting too much oil in since what you describe is from too much. The thinner ATF would create less oil windage between the plate. That is the drag if indeed you have the clutch set correct. It is very easy to not get all the play out of the clutch before the 3/4 turn back off. Then, you have too much play and not enough lever travel to break clutch plate far enough apart. However, for the clutch, ATF works better then anything. The problem is what else that is being torn up from too thin of oil is also important.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Road Master
Joined: Jun 2013
Posts: 1,181
Likes: 98
From: north of the south pole
I've been running Type F from walmart since '99. No probs.
When I got my '03 RK (used) the compensator did some weird slipping **** while feathering the clutch on take off. I switched it over to type F. Probs got better then gradually went away.
When I got my '03 RK (used) the compensator did some weird slipping **** while feathering the clutch on take off. I switched it over to type F. Probs got better then gradually went away.
Road Captain
Joined: Apr 2013
Posts: 583
Likes: 4
From: australia
You are probably putting too much oil in since what you describe is from too much. The thinner ATF would create less oil windage between the plate. That is the drag if indeed you have the clutch set correct. It is very easy to not get all the play out of the clutch before the 3/4 turn back off. Then, you have too much play and not enough lever travel to break clutch plate far enough apart. However, for the clutch, ATF works better then anything. The problem is what else that is being torn up from too thin of oil is also important.
a lot off cars also use ATF in their gearboxes these days, just run what makes you happy. and don't get fooled by the typical Harley bullshit ( it must be only the best)
:i con_fryingpan: