ATF in KDX Gearbox....

[KDXRyder200]

Well i used to experience the clutch drag that you guys talked about in the
"kdx clutch questions" thread. Well there is a remedy without tearing
apart your bike to put better clutch springs in or a spacer in. Just use
some Dextron/Mercon Type III Automatic Transmission Fluid. It works
wonders. I was using regular 10-30 Motor Oil in it and i had to adjust the
clutch lever adjusted all the way out to get engagement without it
lurching. Once i did it without the clutch adjusted out and when i popped
it in first gear the clutch dragged so bad it moved 3 feet before it quit.
And when i tried to start it back up in gear it would move the whole bike
when the kick started went down. When i put the ATF in I adjusted the clutch all the way back in and it doesn't lurch like it used too!
I have heard many things about using ATF. They say it causes knotchy shifting...it doesn't. The 2-stroke gearbox is set up like an automatic cars gearbox which allows you to use ATF in it. If you do decide to put it in your gearbox, put a whole quart in, not what the manual recommends. If
you have any questions you can e-mail me at
[email protected] THANKS!

 

[Knobbyjake]

I used to run ATF in my KX 500 and never had any problems. I'll second the motion!

 

[Jeff Gilbert]

What are the types of ATF you don't want to use? ie; synthetic, with additives, etc

 

[G. Gearloose]

Originally posted by KDXRyder200
The 2-stroke gearbox is set up like an automatic cars gearbox

Uh, no....

The straight-cut gears in a motorcycle gearbox don't look anything like the constant-mesh planetaries in a slushbox, and see higher impact and sheer loading.
Also, the slushbox's BAND clutches see momentary action with short duty cycle. A motorcycle disk clutch can see extended abuse and long duty cycle.
A slushbox has pressure lubrication, a motorcycle gearbox is splash lubricated.

I admire your enthusiasm and I'm not saying some ATFs won't 'work' , but your premise is very false, and better shifting doesn't neccessarily equate to whats best for the hardware.

 

[skipro3]

Has anyone had a negative experiance with ATF in the gearbox? What formula or brands are used by those who use ATF and why did you chose that product?

 

[NYkdxer]

I use Type-F ATF in my '89 KDX and have had no problems whatsoever. It definitely shifts better than it did with the 10-30 in it when I bought the bike. The previous owner was VERY easy on it, so the tranny is in good shape. As for which type to use, Type-F is supposed to be the best. I buy mine at wally world for $1.25. I don't bother with synthetic as it is more pricey and I like to change mine every 3-4 long rides.

 

[farmerj]

While I voice my ignorance on the subject, I will say that all of the threads I've ever read on this topic recommend using Type F. Does anyone know what the problem is with using Dextron/Mercon??

Jeff

 

[craig_enid]

I use a 50/50 ATF type F and 0-30 Mobil syntec.
I also put in aftermarket springs, as well as replacing the stock KDX clutch plates with stock XR250 plates.
Here's a picture of a KDX plate sitting on an XR250 plate to show the larger contact area.
http://community.webshots.com/photo/74476185/77652250yQubRE
Oh yeah, a Hinson clutch basket, too.

 

[KDXRyder200]

I just picked up what our local mechanics had which was regular Valvoline Dextron/
Mercon ATF fluid. As for the Type-F that is what they use in Hydrostatic transmissions.
You can use it..i would just stick with the Dextron/Mercon. As for how the 2-stroke
gear box setup i might be wrong but i was talking about a cars automatic transmission
not a hydrostatic transmission found on a lawn tractor or a combine.

 

[KDXRyder200]

I might still be wrong but i read it out of Motorcycle magazine.

 

[G. Gearloose]

Originally posted by KDXRyder200
i was talking about a cars automatic transmission

Uhh, me too. ;)

 

[KAY DEE EXER]

IMHO I have found type F to be very knotchy at shifting in my 98 200 and I kept hitting neutral between 1st and 2nd, but have had no problems with 10w30. That being said it seems to have the opposite effects on most peoples KDX's here. So you decide for yourself...BTW both the type F ATF and 10w30 are made by Valvoline.

 

[G. Gearloose]

Originally posted by KDXRyder200
As for the Type-F that is what they use in Hydrostatic transmissions.

And in older 'F'ords and Toyotas. 1968-1977 thereabouts. Maybe they got the idea from Tractor Magazine. ;)

Search the forums, there are years of discussion avail on the ATF thang. It is of course still not settled, and perhaps doesn't matter much.

 

[Wolf]

I have used ATF type F for over one season in my KDX and had good success with it. Before that I used to run Mobil red cap. When I switched it seemed that the shifting has gotten a little smoother, could just be my imagination, though. I switched because I figured if it works its even cheaper.
I used the Walmart brand and occasionally I use castrol type F. To me, one is as good as the other.
I have run the Dexron/Mercon stuff in my son's Husky 50...based on a recommendation. No complaints there either....

 

[stinx]

atf Type F in my o2 KDX 200 since new. I have no problems bike shifts great

 

[pketchum]

Been using Texaco? ATF Type-F in my racing Hodaka's for the past three years. I rebuild my own engines and would see transmission problems if there were any. I switched from high-dollar oil to the ATF Type-F on the recommendation of a motorcycle mechanic friend who also raced and wrenched on his own.

I'm sure that I'll try this on my new-to-me '94 KDX 200 once I get to ride it a little. We've 7" of snow here in Kansas City right now, and another inch is expected tonight.

 

[canyncarvr]

I don't see a mention of what type 'F' is for.

It's for use with organic material plates/clutches etc....as was used by ford. That was <1980 or so. Admittedly, this is what I've read and been told by those that should know....that don't necessarily mean it's so.

Some basic 'type f' info can be read here .

Note that the fluid was specifically designed to allow clutches to 'lock up' or 'engage' quickly. Friction modifiers have been added to enhance the 'stick'. Note, 'friction modifiers' include both additives that make things stick more and/or additives that make things stick less.

Ando sums it up (from the below posted link):

What this means for us is that the Type F fluids will allow our clutches to hold tighter with the same clamping pressure then with an ATF or even with a motor oil.

DO read the whole thread (again...linked below)!

Read this for a treatise on atf in the gearbox.

A btw (related somewhat to ando posted), my b-in-l is a diesel mechanic. I recall him mentioning some big truck trans (manual) that had atf in it. That obviously being a crock and not up to the job, they replaced it with gear oil.

It wasn't a week before the trans disintegrated.

They kept the atf in the next one!

That relative to shear strengths and loads in gear-sets.

Then, there's: (from here. )
'The basic problem with Dexron is that it has very poor lubication qualities.' They go on to say that type f is worse in that regard.

Mr. fluffy bunny:

I didn't see an update from you on the drn atf thread linked above regarding the $75 papers you were going to procure regarding the use of atf. Did I miss it?

(From: ANSI/AGMA 6010-F97 Standard for Spur, Helical, Herringbone, and Bevel Enclosed Drives
ANSI/AGMA 9005-D94 Industrial Gear Lubrication)

Maybe you did not come up with anything, so didn't bother?

Thanks.

 

[levert]

Does putting in some of these modern super slippery oils degrade clutch performance?
I haven't run ATF ,mostly I run older style oils H or G .
Everyone has a different take on oil that is for sure,I've been told that some of the older oils have more additives to protect high pressure gears, additives such as zinc.Some of the newer oils take that out and substitute other chemicals, a lot of this has to do with emmisions and the life expectency of catconverters.
Anyhow I degress, the more I read, the more I know that this really is a science on to its own!
Some of the gearbox oil sure is expensive, I've tried some stuff that was $18 a litre, OUCH!!! Can't say I noticed a huge difference.

 

[paul6585]

My high school Auto Mechanics teacher (20 yrs ago) taught us that you can use ATF in place of power steering fluid. Does anyone know if you can use power steering fluid in place of ATF? I hate to throw anything away.

 

[Bodge]

Has anyone tried "Super Tech" ATF type F? Got it at walmart for like a dollar so its no loss if it wont work lol.

 

[s.d.duner]

Type F is for Hydrostatic transmissions? I dont know what that means. Used in lawnmowers? Uh Oh. My '67 mustang calls for type f in the tranny and p.s. pump. Its got a C4. Guess its hydrostatic. Sounds cool

 

[Braahp]

Type F is what you should use. I don't remember why........but thats what everyone says. It worked ok for me but required changing after every couple of rides. Didn't seem to shift as well either. The WalMart worked just as well as others. I switched back to Mobil 15-50. My KDX likes it much better and I do to cause I don't have to change it but every couple hundred miles.

 

[Rich Rohrich]

Originally posted by canyncarvr
Mr. fluffy bunny:

I didn't see an update from you on the drn atf thread linked above regarding the $75 papers you were going to procure regarding the use of atf. Did I miss it?

(From: ANSI/AGMA 6010-F97 Standard for Spur, Helical, Herringbone, and Bevel Enclosed Drives
ANSI/AGMA 9005-D94 Industrial Gear Lubrication)

I couldn't work a trade for the papers and didn't have $75 worth of interest in the subject matter so I moved on to more interesting pursuits. :thumb:

 

[BRush]

To expand upon the quote that CC referenced above:

Posted by Ando on 10-09-2000 09:22 PM:
I think we're throwing a lot of stuff out there with only a tenuous regard for reality.

First off, ALL transmission fluids have friction modifiers in them. The old Type F fluid uses a modifier that increases the static coefficient of friction to a higher value then the dynamic coefficient of friction. The newer Dexron and Mercon fluids have a static coefficient of friction that is lower then the dynamic coefficient of friction. What this in effect does, is allow the Dexron/Mercon fluid transmissions to slip more and engage more slowly and smoothly, while the Ford transmissions shift quicker with a faster lockup. The old Ford transmissions (C-4, C-6) were designed with a smaller clutch area then their GM Hydramatic counter parts. The newer Ford transmissions changed to the GM smooth slow shift theory with the AOD series and maybe some of the older weird ones (FMX?). What this means for us is that the Type F fluids will allow our clutches to hold tighter with the same clamping pressure then with an ATF or even with a motor oil. B+M has always recommended at least type F fluid for any of their transmissions, for precisely these faster, harder shifting properties and the Trick Shift also uses these friction modifiers.

It would be interesting to see how the friction coefficient of normal motor oil or gear oil would compare.
The key thing to glean from this is that for some clamping pressure “X” , the same clutch will slip sooner using Dexron/Mercon ATF, than it will using Type F.
Here’s my take on the whole thing: Since for most “normal” dirtbike uses, both of these ATF’s are going to provide your gearbox with adequate lubrication then the question of which to use comes down to how it works in your bike. Getting smoother shifts and no clutch slipping with Dexron/Mercon?. Then hey, stick with it. If you notice clutch slippage on a long uphill when the bike is hot, then that should tell you something. If you can’t tell the difference, stay with Type F since you never know when the higher static coefficient will work to your advantage.

 

[canyncarvr]

Hey! It's no fair just telling all......make 'em go look for it!! ;)

Thanks for the update mr. rohrich. I'd looked for additional input to the post a few times.