Simplicity 12.5LTH Riding Mower Questions

[JR]

I just bought a used simplicity rider off my neighbor. It has a hydrostatic transaxle in it and simplicity's website states to change the hydrostatic fluid every 400 hour and every time the transaxle is serviced. The website stated to use a "4.3 pints (2.0L)SAE 30 Premium Grade Engine Oil." I was wondering if you guys would have any suggestions on the brand and type of oil to use. Also I was wondering if the 15w40 pennzoil that I have been using for the engine oil would be also ok to use instead of the SAE 30 that they say to use as hydro fluid. If I could it would make servicing easier. One oil for everything and not two different oils for two different duties. And if this practice would cause problems what would they be. I would like to hear all of your suggestions and comments.

Thank you
KC

 

[JR]

Also FWIW, the transaxle is either a Eaton 750 or 751 series. I don't have the numbers off the axle to know for sure, but when I do I will let you guys know.

 

[Jon]

I think the Simplicity manuals were later updated to spec ATF or hydraulic fluid, I'm not sure which. I use ATF in mine (mine says either low-ash 30 weight or ATF, ATF preferred) and I've got just shy of 1000 hours on it, and it's perfect.
My dad (and his 3 mowers of the same vintage/maint.) are the same, but with a bunch more hours.