Thanks for the clarification. I may give the Syn ATF a try next time around. I have always preferred ATF for efficient plate separation. But do have a little concern about compensator issues. Not worried about bearings as they did just fine in 205 transfer cases in 4/4 chevy's.

 

It is "Hard to prove a negative."

 

========================

" Not worried about bearings as they did just fine in 205 transfer cases in 4/4"

Well the problem with that is the bearing/x-fer case was designed to be lubed by ATF but the bearings & compensator in HD primary wasnt which is key point.

Also,one of our fellow forum members got in touch with an ATF mfg and here's what they had say about using ATf in an motorcycle primary when asked pasted below.

" I emailed them for some enlightenment and one of their engineers said ATF was a light weight hydraulic fluid designed for high pressure lubrication. It was not suitable for the large inner primary bearing. "

Now thats exactly the concern i had with thin atf not having the proper viscosity and additive pkg with proper anti wear agent lvl etc to properly protect lrg bearings and or compensator under all cond all the time & why i wont run it.

My 09 shifts fine and neutral is always easy to find running spectro's primary oil specifically formulated for lrg HD v-twin primary case and yes it does the normal clunk when shifting thing many hd's have done for many yrs & thousands of miles with no trans problems.

Scott

 

Scott,

Once again you're spreading the false information about ATF being thinner than fluid "designed" for primaries. It's just in your head, and you really need to do some research. This is what... the 4th or 5th time? You are parroting some information someone told you. Think for yourself, look around.

I assume you would say Redline V-Twin primary fluid is an acceptable choice?

From THEIR website...

TYPICAL PROPERTIES

API Service Class GL-4 SAE Viscosity Grade (Motor Oil) 5W30 SAE Viscosity Grade (Gear Oil) 75W80 Vis @ 100°C 10.4 Vis @ 40°C 54.1 Viscosity Index 185 Pour Point, °C -50 Pour Point, °F -58 Brookfield Vis @ -40°C, P 120
Now REDLINE'S synthetic High Temp ATF that I recommended...

"Use where Dexron III®, Dexron II®, Mercon®, or GL-4 gear oil are recommended"

TYPICAL PROPERTIES

Vis @ 100°C, cSt 10 Vis @ 40°C, cSt 53.9 Viscosity Index 172 Pour Point, °C -51 Pour Point, °F -60 Brookfield Vis @ -40°C, P 175
Scott, these are FACTS from Redline's website. If you look at the viscosity @40c and 100c you will see they are almost EXACTLY THE SAME. And, they are BOTH RECOMMENDED FOR GL-4 applications.

Instead of repeatedly posting the same tired line, post some facts, with the source, like I did.

Maybe you can explain it to this guy...

https://www.hdforums.com/forum/prima...l#post14098134

 

you hit the nail on the head with that one

 

This voids your entire post. Everyone knows that ATF=DEATH is an old wives tale. ATF maims people, no one ever dies.(unless they add friction modifiers)

Happy Motoring!

 

Leftcoaster, your quote.
My experience is that ATF works in H-D primaries and does so very well. I have had zero issues in 40+ years using it.

40+ years ago Harley 1200cc clutches were dry???????

 

I have always been of the opinion that a "properly" adjusted clutch had more to do with whether a clutch shifted smoothly (and quietly) or not. If it is adjusted "properly", my experience has been that you could put damn near any brand in the primary or gearbox with the same results. I do think that it is important to use viscosities in the range of what the manufacturer recommends though if you want to enjoy long bearing life.
To each his own. That is what makes a horse race interesting!

 

Unfortunately you cannot adjust a hydraulic clutch.


Absolutely.. what works for you IS what's best.

 

I use Harley primary in my car and no problems!