Auto Trans Oil

[nwh1-0475 0]

I know this has been debated many times on here, but I need to know what oil to put in my tranny. the pump that I am using and lift cyl appreaded to have a red colored oil in it, I am assuming it had auto tranny oil in it. Should I just stay with the auto tranny oil or switch to a engine oil? Auto Tranny fluid, what type? Engine oil, what type?

Thanks, Dustin

[kpinnc 14,585]

Some of the older Sundstrands used ATF, but the auto trans manual says it is OK to change them over to 10W-30.

If you have an Eaton hydro, you MUST use 10W-30.

With the Sundstrands, the catch is, you must get ALL of the ATF out of the system. The cylinder, and all of the hydraulic lines need to be emptied out. ATF and motor oil don't mix.

I opted to stay with DextronIII in my Sundstrand. It's used that for 35 years, and the inside of my tranny is cleaner than any mechanical equipment I have ever seen, with very little wear. If it's been good enough until now, I'm not gonna change it.

Kevin

[Old Dave 0]

My 69 Charger 10 had Dextron in it when I got it and the manual says to use ATF and that's all I have ever put in it. The manual for the 1974 B-100 we have at the lake, says you can use either ATF or 10W30 motor oil. My father in law always used motor oil in it. They are both Sundstrand hydrostat's.

[WheelHorse_of_course 99]

Thanks for looking at what was in there first, and telling us. The answer is:

Stick with Auto since you do not want to have to disassemble to purge the system.

You want a fluid that is compatible with "Type A" or "Dextron" or "Dextron II". IIRC that means you'd be using Dextron IV but read the label carefully as they are now using the Dextron name for some that are NOT compatible with Dextron.

Be sure to keep all debris out of the system and you should also replace the filter with the proper type (not an oil filter but a transmission filter).

Best of luck.... :banghead:

[nwh1-0475 0]

Thanks for all of the info. What happened is my old tranny broke a couple of bolts out of the differental and sent them through the bottom of the case. I got another tranny and used the case off of it but I am still using the pump from the original one, so I will use ATF in it.

Thanks, Dustin

[kpinnc 14,585]

What happened is my old tranny broke a couple of bolts out of the differental and sent them through the bottom of the case. I got another tranny and used the case off of it but I am still using the pump from the original one, so I will use ATF in it.

If you haven't already done so, be sure and replace the self-locking nuts on the differential when you put it back together. And I would NOT use the nylon insert type, as that tranny could get hot enough to soften the nylon, which would defeat the whole purpose of having them.

It's not unusual for re-used lock nuts to loosen up on a WH differential, which allows the bolts to back out and contact the case. Lots of people have had the type damage you speak of for the very same reason...

Kevin

[nwh1-0475 0]

Wellllllllll, it is already back together with the nylon lock nuts. Do you think it is worth me taking it back apart to replace them with the other style of locking nuts. I would hate for this to happen again. I also don't want to have to take back apart, with my job and kids it has already been sitting in pieces since april, and I'm down to the point of adding oil.

Thanks for all of the advise, Dustin

[wh500special 2,262]

Wellllllllll, it is already back together with the nylon lock nuts. Do you think it is worth me taking it back apart...

I don't recall all properties of nylon, but depending on the specific polymer (it is probably Nylon 6 since it is cheap and common) it will have a melt temperature of about 400 F. The usable temperature range where it still retains many of its physical properties will top out probably around 200 F. Unless you overheat your transmission, it probably won't ever see 200 F.

Personally, I think if you tightened those bolts/locknuts securely you'll be fine for a l-o-n-g time. I'd use it as-is and make a mental note that perhaps some day when you have the time you crack it back open and replace the nuts with something better to put your mind at ease and your doubts to rest.

No matter what temperature these types of locknuts are used in they all will eventually succumb to long term "creep" and will wane in effectiveness. Just a fancy way of saying that eventually the plastic loses its desire to bounce back to its original shape. This always happens with these type of lock nuts, but since most are used at ambient temperatures the creep process is a lot slower. i still use them all over my stuff though without hesitation since they do work well - and install easily - for a long time.

These bolts inside the transaxle do loosen over time and I have seen many, many tractors that have had damage to the casing just as you described. Seems especially prevalent in the D-series tractors. I've never had to do the repair myself though (yet) but will eventually find myself in that situation I am sure.

Really, the polymer guy in me says these nylock nuts should be OK in your application. if they were "flight critical" parts on an airplane though I might feel differently...but that's a different ballgame. I'd leave it as is, but please do what makes you comfortable.

Best of luck,

Steve

[linen beige 15]

We really need your model number to answer you correctly. It may have used type "F" or Dexron II (BTW, there is no "T" in Dexron.) General Motors is now using Dexron VI and plans to discontinue all the other Dexron types in the near future. So, if you use Dexron, you may consider going with the new stuff.

[kpinnc 14,585]

Really, the polymer guy in me says these nylock nuts should be OK in your application. if they were "flight critical" parts on an airplane though I might feel differently...but that's a different ballgame. I'd leave it as is, but please do what makes you comfortable.

You made me think of something I've never considered before Steve!

Next time I open one, I'm gonna replace the nuts and bolts with ones drilled for safety wire! Lock all the nuts together, lock all the bolt heads together!

Won't have to worry about it then!

Now, if I can just find my safety wire pliers....

Kevin

[nwh1-0475 0]

My model # is in my sign in name. Is that something that I can find out on the Toro site. I'm not real fimiliar with that web site yet.

Thanks, Dustin

[linen beige 15]

My model # is in my sign in name. Is that something that I can find out on the Toro site. I'm not real fimiliar with that web site yet.

Thanks, Dustin

Duh-eee. I didn't notice the model #

That's a 1973 10 automatic. Should have a ten horse power Kohler.

The WH lube recomendation chart shows that it could have used 10W-30 or 10W-40 engine oil, or Dexron II. It advises to determine which type was used and replace with same. If yours had ATF in it that's what needs to go back in it. However, like I mentioned, GM has introduced Dexron VI and is planning to discontinue all other Dexron types, so you may want to go ahead and pour in some type VI.

Tor's site accepts the model # 1-0475, but I notice the lube chart shows it as 1-0470-5. Maybe a misprint in the book? :banghead:

[wh500special 2,262]

Wow, lots of good advice on this thread so far from the other guys. Hopefully next time somebody needs this question answered they stumble on your thread before posting!

If you had pink fluid in it already, you're supposed to use the Dexron III in your tractor. If they are indeed phasing it out and replacing it with a newer version you will be safe using it in your transmission since you can bet GM - or whoever is making the formulaton change - has researched the compatibility of the chemistries of the old and new systems.

I personally favor using motor oil in mine, but that's just so I don't have to buy and store yet another material in the garage. But most advocate that you purge the whole system when you make the changeover to motor oil. You can accompishe the purge by complete disassembly of all the parts in the system (preferred method), or you can refill the system with the new fluid, run it for a while, dump, refill, run, dump, refill, replace the filter. What little bit of the old stuff that remains after these serial dilutions will be negligible. But it is wasteful to dump so much oil that would have otherwise had a long life in front of it.

If you do a fluid purge/change it is possible that you will run into seal leakage (axle shafts, pump shafts, etc) because the different fluids may impact the seals in different ways. I have an 18-Auto that currently leaks like a sieve and has ATF in it. I will be changing it over next time it is due for a service and maybe I'll get lucky on the seals "self correcting". I won't bet on it though, but it is worth a try since it is virtually impossible to remove a hub from a 35 year old D-axle since they are so darned long and are rusted into place....almost as difficult as pinning a politcal candidate down on their feelings about how to deal with an issue.

I would imagine that the original reason Sundstrand/Wheel Horse specified ATF over motor oil in 1965 was that the transmission fluids of the day were better suited to handle the temperature and pressure cycles that occur inside one of these transmissions than were the motor oils of the same period. And the thinner ATF may have been needed to prevent excessive pressure generation when cold.

Additive packages (surfactants, detergents, thixotropes, etc) too were probably different and transmission fluid was a better fit at the time. It is also possible that they were also after something that was not capable of suspending impurities so that they dropped to the bottom of the axle casing rather than get pumped around.

With the evolutions in oils over the past 40 years the properties that caused them to originally specify ATF must have changed since the change was made to motor oil in the mid 1970's by WH. It used to be that "motor oil is motor oil" but the stuff from the Vietnam era is certianly different than what we have today.

Motor oils also probably provide better lubrication to the gears and such that are inside the transaxle sump than did the lower viscosity (thinner), lower surface tension (not as "clingy") ATF. So the change was made. Oils today - especially synthetics - are far superior to what was dumped in these things in the good old days.

The fluid in a hydrostatic transmission and that in an automotive type transmission serves different purposes. In a true automatic there are all kinds of wierd dynamic (shear) requirements (in and around the torque converter) for the fluid to be able to transfer power and be able to deal with excessive heat that results from the clutch bands and all the other unique components in a true automatic transmission. In a hydrostatic transmission you replace all the complex mechanics and dynamic fluid effects with a pump and a motor (which is just another pump being driven by the fluid instead of actually pumping the fluid) that operates at a (mostly) constant pressure - hence the term hydrostatic and not hydraulic. Almost any fluid would work, but oils of course need to be used to serve the corrosion and lubrication needs of the transmission and transaxle.

Use the Dexron III or its modern equivalent unless you want to do a purge.

Steve

[linen beige 15]

Just wanted to point out something that may not be known by all our readers. Wheel Horse originally specified the use of type "A" ATF but later recommended using Dexron II due to type "A" becoming almost obsolete. Now Dexron II is almost obsolete so Dexron III is a suitable substitute. That's why some old service manuals say use type "A" but the newer ones say Dexron II (or III.).

Steve has made some very good points about the differences in oil and ATF. One thing to think about is that ATF is NOT meant to lubricate or at least not very well. It was developed for use in automatic transmissions that required consistent fluid pressure while still allowing for friction drive clutches. A side benifit is that it keeps everything squeeky clean. I suspect that WH realized that engine oil would provide sufficiently consistent fluid pressures for their needs and also provide the lubrication needed in the geared portion of their transaxles, hence the switch.

On the subject of purging: I'm hoping one of the more experienced WH mechanics will chime in on this thought. Would it work to connect a source of new fluid to the fluid return port used for hydro lifts, etc. and a catch container to the fluid out port? Seems you could just run the unit until new, clean fluid started filling the catch container. If I tried this I would likely drain as much of the old fluid as possible the conventional way and fill the reservoir with new fluid before starting the purge. Do you guys think this would work, or would the new and old mix too easily in the system before getting ejected?

[wh500special 2,262]

On the subject of purging: I'm hoping one of the more experienced WH mechanics will chime in on this thought. Would it work to connect a source of new fluid to the fluid return port used for hydro lifts, etc. and a catch container to the fluid out port?

The only reason that that this might not work would be if that part of the system doesn't develop sufficient suction to draw the new fluid into the system. It might, but I don't know. Hydraulic pumps really don't "suck" very well, but I don't really know what the answer here would be without trying it.

Otherwise, I think it is a great idea. you'd have to continually stroke the lift cylinder while doing the operation to purge it and its lines too.

As far as the mixing in the lines is concerned, it would be fine. Because the flowrates in the system are sufficiently low the fluid should be moving in what is called laminar flow. It will travel most of the lines and such in a "plug flow" scenario with minimal - if any - turbulence. I think mixing would be a non issue.

If you can figure out a way to try this I'd love to hear how it went.

Alternately, since on a Sundtrand the filter only filters the oil that is returning to the transmission case (there is a very coarse internal strainer on the intake side of the pump too, but it only keeps out the boulders - everything else gets sucked into the transmission), you could dump the fluid from the transaxle case and overfill it with new fluid. Remove the filter and start the tractor up and let it run until new fluid starts dumping out of the filter base into your bucket. Monitor the sump level while running a little longer to make sure you got it all then kill it, replace the filter, and adjust the fluid level to where it should be.

i think I might try this over the winter on that 18 auto. Great idea Jim!

Steve

[wh500special 2,262]

After I posted that something occured to me...

Since the fluid flows into and out of the lift cylinders and its associated lines along the same return path, you probably never will purge all of the old stuff from those lines. If you wanted to be a stickler then you'd probably have to break those connections and purge the lines with new fluid then reconnect them.

I personally won't bother with this step though since I don't feel that the residual fluid poses any compatibilty problems and "dilution is the solution" for me. I'm not a hydraulic engineer though...just a Chemical Engineer so take my advice with a few micro crystals of NaCl.

Steve

[linen beige 15]

After I posted that something occured to me...

Since the fluid flows into and out of the lift cylinders and its associated lines along the same return path, you probably never will purge all of the old stuff from those lines. If you wanted to be a stickler then you'd probably have to break those connections and purge the lines with new fluid then reconnect them.

I personally won't bother with this step though since I don't feel that the residual fluid poses any compatibilty problems and "dilution is the solution" for me. I'm not a hydraulic engineer though...just a Chemical Engineer so take my advice with a few micro crystals of NaCl.

Steve

That is true as long as the lift cylinder piston and it's seals are in the system. Disconnect those hoses from the cylinder and us them for your old fluid out/ new fluid in lines. The lift valve is really a flow direction diverter valve. It puts the pressure from the trans into the correct line. Just place say, the "up" hose into your dispossal container and the "down" hose into the new fluid container and place the lift handle in the "up" position. Now the only part left un-purged is the lift cylinder itself. That is easy to do by hand cycling the ram.

[bluetuna08 0]

I have the sunstrand hydrostatic rearend in my electro and I opted to not use ATF in it.

I went to tractor supply and picked up tractor transmission oil and hydraulic fluid due to my hydraulic lift cylinder that I just replaced with a brand new one. in addition I changed the spin on oil filter.

new dextron III is not the same as the old ATF type A stuff anyway so a relatively low tech oil with a good antifoam agent is what I want.

as for the ATF type A not mixing it is a minor amount in my case because of the new cylinder and hydraulic lines. in any case I think that the non mixing issue is a non issue.

I will quantify by saying I am a tribologist so I have justified my switch in my own mind.

[nwh1-0475 0]

Well guys, I got it all back together finally, put 10W-40 in it, I have ran it for only a very short period to time and I am extremely pissed off. Push the directional arm for the tranny forward and the tractor moves backwards and visa versa. What have I done wrong? I switched the lines going to the cylinder thinking that had something to do with it, wrong the lift cylinder just operated backwards then. I don't know what could be wrong because I didn't take the pump apart. I am almost positive all the gears are in correct, of course I don't think you can put them in wrong. It is like it is pumping backwards because it hauls a** in reverse or what should be forwards. I did take that cone shaped cover off of the pump at first and decided that I didn't want to do that it was a mistake, could I have put that back in incorrectly? Please help.

Thanks, Dustin

[linen beige 15]

:omg: :USA:

[wh500special 2,262]

Well guys, I got it all back together finally, put 10W-40 in it, I have ran it for only a very short period to time and I am extremely pissed off. Push the directional arm for the tranny forward and the tractor moves backwards and visa versa. What have I done wrong?

I think you made the very easy and forgivable mistake of installing the hydrostatic motor cover 180 degrees out of phase. take the cover back off thus exposing the cylinder/piston assembly, rotate the cover 180 degrees (half turn) and reinstall.

Forward should be forward and reverse should be reverse then.

Let us know whether this works or not (it should).

Steve

[wh500special 2,262]

I am a tribologist ....

Wow, now that is a pretty rare specialty!

When I used to work for a bearing manufacturer we frequently ran into tribological issues with our bearings and the shafts they supported. Interesting work to be "dithering" away your time on..."stick/slip" around, there wil be lots of stuff on these tractors where we will want your help...

Not even a word I knew existed until a few years ago.

I mentioned in another thread that there is little danger in mixing the two fluids, but the common practice to avoid any doubts is to flush and fill with new stuff. I am reassured in my opinion hearing that you've have had good luck with your tractor.

Steve

[bluetuna08 0]

thanks, where I work in a paper mill as a reliability engineer I have to be a tribologist, vibration analyst, and Infrared specialists...as well as a mechanical engineer.

[nwh1-0475 0]

Thanks for the info, I will try to get the cover reversed today and let you know. I wouldn't have thought that would make that much kind of difference. Well see.

Thanks, Dustin

[1973Auto 80]

Ok, here is my 2 cents, I am reading this right from my owners manual. " TRANSMISSION.........Dexron or Type F Hydrostatic oil (Wheel Horse Part number 8827) Iown a 1973 Auto also. 12 hp. She is a tank!!!!!! :banghead: