Motor oil or ATF in Sundstrand ??

[EdG. 5]

I have a 1969 Electro 12. Wheelhorse says the Sundstrand came with automatic transmission fluid (Dextron II), and that is what I have in mine. But I read that a lot of people convert it over to 10w30 motor oil. Is there any advantage in doing this? I believe Wheelhorse started using 10w30 motor oil somewhere around 1972 in their Sundstrand equipped hydro's but I don't know why. Wheelhorse say

[Retired Wrencher 5,511]

:thumbs2: Ed in my 1075 I use 10/w30 per my W/Horse dealer because A fluid is hard to find. been using for awhile now it seems to work fine Gary B.....

[TT-(Moderator) 1,145]

The fluid type changed in 1973 when the Sundstrand units went from the hydrogear to the piston-to-piston.

Dexron III is the best modern substitute for type "A" fluid and Dexron II.

As already stated, either fluid will work in the hydrogear version, but a change from ATF to motor oil does require a thorough draining since the two fluids aren't overly-compatible.

That doesn't necessarily mean that you need to disassemble the entire unit to get every last drop of ATF out, but you should plan on changing the fluid & filter a few (operating) hours after the initial switch.

[EdG. 5]

Is there any advantage in using motor oil compaired to the ATF ?

Ed

[EdG. 5]

Oh, wait a minute, I think I would have to convert my Sundstrand to a 'piston-to-piston' in order to use motor oil.

Is that correct?

[TT-(Moderator) 1,145]

Is that correct?

No - either fluid will work as long as they aren't mixed together.

I have no doubt that "universal tractor fluid" (UTF) would also work, but I haven't had the opportunity to try it.

[kpinnc 12,464]

I would add that my Bronco 14 was full of ATF when I restored it, and when I took it apart I've never seen something as clean as that transmission was. There was virtually no wear, and no crud in the sump either. I'm sure some of that can be credited to the filter, but it was also the original one as well. I don't think it had ever been changed.

In addition, the Bronco does not need 5-10 minutes of "warm up time" like my 520-H does in cold weather. It's ready to roll as soon as it cranks up. Since the 520-H uses motor oil, it takes a bit longer before even the hydraulics will work.

I put ATF back in it, and hope to get another 40 years from the thing.

Whatever you decide, good luck! :thumbs2:

[EdG. 5]

Thanks to everyone for their input.

This is going to be (for the most part), my snow machine so I think I will stick with the ATF. Sounds like ATF may have a slight advantage in the cold winter months.

Thanks again for your help!

Ed

[WheelHorse_of_course 99]

.

In addition, the Bronco does not need 5-10 minutes of "warm up time" like my 520-H does in cold weather. It's ready to roll as soon as it cranks up. Since the 520-H uses motor oil, it takes a bit longer before even the hydraulics will work.

I put ATF back in it, and hope to get another 40 years from the thing.

Whatever you decide, good luck!

Indeed, the faster "warm up time" seems to be the principle advantage of ATF.

:banghead:

[can whlvr 993]

my c160 auto uses 10w30 and it needs absolutly no warm up time at all,allthough i do warm it up