Sundstrand fluid?

[cdsl810 181]

Just got a 1980 C-125 Auto with the Sundstrand (not sure exactly which model, maybe a 90?). Does it take 10w30 like the Eaton 1100?

Edited August 11, 2015 by cdsl810

[pfrederi 17,169]

Not necessarily.  Early sunstrands used ATF (Dexron) later ones used 10w30 motor oil.  I would stick with what ever is  curently in there as they do not mix well and a complete flushing uses a lot of expensive fluid.  ATF will be cherry koolaid red, motor oil tan.

[cdsl810 181]

Thanks. This is probably one of the last Sundstrands that Wheel Horse used, so I'm guessing motor oil. I did check the level and condition of the fluid before I bought it, didn't pay attention to the color. Then again, maybe my mind didn't detect anything out of the ordinary, since I'm used to seeing oil in there with my two Eatons. The good news is that since I don't have a hydro lift, I should be able to drain virtually all of the old fluid.

One other observation I have made is that the Sundstrand seems to be "tighter" or "more connected" to the motion lever. There is no lag in response. Both of my Eatons have a perceptible "soft start" feeling; they are very strong, but take a fraction of a second to go compared to the Sunny. It's almost like the Sundstrand feels directly linked and the Eaton has more of a smoother, softer, power steering type feel.

Edited August 11, 2015 by cdsl810

[bmsgaffer 2,043]

I have read up on the eatons, and the reason they feel that way is the same reason you can push it without a tow valve. They have "soft start" acceleration valves that bleed off some of the pressure before fully engaging drive. (They also help the unit have a larger neutral range to limit creeping, very multi purpose valves)

I have been trying to figure a way to disable this without making it feel super jerky or damaging the unit. I would be curious what it felt liie without them.

Edited August 11, 2015 by bmsgaffer

[slammer302 2,154]

for sum reason i remember reading some where on here the the sunstrands with out hydro lift used motor oil and the ones with the lift used trans fluid and from what i've seen that has been true the electro 12 i had for a while had the red trans fluid in it and my dads charger 10 with out the lift had motor oil in it and i also noticed it is kinda jerky and will give you wipp lash if not used to it also has been repowered with 16hp kohler so it has plenty of power its his primary lawn mower he says he does not like the location of the motion lever on alot of the newer eatons  

[cdsl810 181]

Yes. In the 48 hours that I have had the C-125 Auto, I can tell you that I really like the placement and function of the motion lever. I am not a fan of the steering column setup on my 520-H because it really doesn't like to stay put, and I find that I have to drive with one hand on the wheel and one on the motion lever. Of course, the best of all possibilities is a foot control, like Matt's... I think that feels nicer even than the factory foot control on my 522xi. And I finally got a chance to look: it is most definitely motor oil in the Sundstrand without hydro lift.