ATF in Primary?

[Jzfn13]

Talking to some old school Harley guys and a lot of them swear by running ATF (auto trans fluid) In the primary. They say it is better on the clutches. While I believe that i doubt it would be as good at lubricating the chain. Its not something I think i would do, but I am interested the hear your thoughts.

 

[50dro]

First thought...I'm thinking no.

If you're real curious, call up one of the clutch manufacturers like Energy One etc and get their 2 cents on it.

Did a quick Google search and it looks like it may be the case for some clutches but I feel it would greatly depend on the clutch material and what the manufacturer recommends for a given application...

Let us know what you find. I'm kinda curious now...

 

[Theycallmecrash]

The primary assembly is a very harsh environment, especially if you like to ride hard.

Primary fluids/oils have certain modifiers molecules that are resistant to "shearing" for example differentials in truck use thick oils with high phosphorus and/or zinc modifiers that resist shearing/wearing. ATF III or VI or what ever ATF you decide on doesnt have these modifiers, but differential also has modifiers that are either too slippery or corrosive for wet clutch components....

...so with those extremes addressed id simply stay with a fluid/oil developed for and states on the container safe for wet cluches or primaries.

 

[go cytocis]

Did a quick Google search and it looks like it may be the case for some clutches

Yup, my Barnett clutch pack requires ATF, and it's all I've run in my primary ever since I installed it.

Think about it; there's nothing in our primary cases that isn't also found in an auto trans.

I have found smoother, quieter & more precise shifts since I began running it.

Plus, if I develop a leak, I'll know immediately which case it's coming from!

 

[go cytocis]

Primary fluids/oils have certain modifiers molecules that are resistant to "shearing"... ATF...doesnt have these modifiers,

ATFs are totally shear-stable. One of the most significant purposes of ATF is to resist shear, after tens of thousands of km (or miles), being thrashed around in the mesh gears of an auto trans.

 

[Theycallmecrash]

Think about it; there's nothing in our primary cases that isn't also found in an auto trans.

Except a sloppy chain directly connected to the crank shaft.

 

[50dro]

E1 Tech Info

Read the end of the first paragraph. They also mention ATF. Note: Even though they mention no synthetics, they verbally told me that AMSOIL was fine to use. They didn't like the H-D oils abut didn't want to single them out on it!

 

[go cytocis]

Except a sloppy chain directly connected to the crank shaft.

Haha, well, not withstanding the "sloppy" part, many auto transmissions use internal chain drives. Chains themselves have pretty minimal lube req's. ****, my dirt bike's chain is mostly lubed with mud!

 

[Theycallmecrash]

ATFs are totally shear-stable. One of the most significant purposes of ATF is to resist shear, after tens of thousands of km (or miles), being thrashed around in the mesh gears of an auto trans

Not to argue but why dont these use ATF in differentials? Because the metal on metal forces are much greater, and stronger shear resistence is needed. Same with our primaries, wer kinda in the middle of auto transmissions and differentials.

 

[go cytocis]

 

[Theycallmecrash]

Barnett [up]

Always follow aftermarket instructions. Especially from a quality manufacture/parts supplier.

 

[EricZ]

Ya ATF easily handles the XB primary and trans lubrication requirements. I have found that it makes shifts slightly more difficult in 2003-2005 trans(I think its from the interface between the aluminum shift drum and steel shift fork pins). 2006+ trans seem to shift great with it. I'm not saying it is "better" than other primary lubes.

 

[user_deleted]

my logic is why muddy up the waters on a topic that's been discussed and beaten to death on this forum. notice the additional wording on your sticker and every other sticker/pamphlet/label/decal from a barnett clutch pack. it states "or any light viscosity motorcycle specific oil". they are talking about any motorcycle oil in the 10-30/5-40 viscosity range designed and produced for cycle engines with wet clutch applications and common trans/engine sumps....as in virtually every jap and italian bike built since 1969. pick up any container of castrol act-evo, yamalube, honda line.....the list is long. all those oils meet this requirement.

 

[go cytocis]

they are talking about any motorcycle oil in the 10-30/5-40 viscosity range designed and produced for cycle engines with wet clutch

Great point Lunatic. Specifically, look for JASO MA designation on the label for certainty that the oil is wet-clutch compatible, & shear stable.

 

[go cytocis]

Ya ATF easily handles the XB primary and trans lubrication requirements. I have found that it makes shifts slightly more difficult in 2003-2005 trans(I think its from the interface between the aluminum shift drum and steel shift fork pins). 2006+ trans seem to shift great with it. I'm not saying it is "better" than other primary lubes.

Interesting observation; thanks for sharing.

I am on an '06 which I had been running 80w90 GL in prior to switching to ATF. The difference between the two, particularly when cold, and especially during the initial engagement of first gear, was remarkable; much less clunky.

 

[WIGGLE2]

As mentioned.... a lot of conversation on this in the past. As far as someone's post on this thread regarding no chains in an auto trans....correct....but they also use ATF in nearly Every Borg Warner 4x4 transfer case....and THAT is a chain. Try it....if you like it and it works for you....GREAT!

 

[snrusnak]

Very interesting. I just swapped a trans and transfer case in my neighbors jeep saturday and the transfer case called for ATF +3 or ATF +4, was kind of shocked to see that...

 

[kelley386racer]

I have run ATF in my dirt bikes for years and performed much better than motor oil. I started running it in my XB12 as well and the shifting and clutch engagement is much better. I do run the Mobile one full synthetic. The environment of our primary is very similar to a automatic transmission, much more so than a normal rear end/ differential or manual transmission.

 

[go cytocis]

regarding no chains in an auto trans....correct

My first car in high school was an '88 Chev Beretta with 3-speed auto trans and I distinctly recall it had a chain which shared common ATF with the clutches, gears, and hydraulic circuits...

 

[Jzfn13]

I appreciate all the input. Makes me actually want to consider giving a go for my next change. Curious to see if I notice any difference.