We have a White Outdoor riding mower with hydrostatic drive. It's mid or late 90s vintage but still runs and functions great. Want to keep it that way.

I'm wanting to change the oil and filter for the transmission but I'm not having any luck figuring out what oil goes in it. Oddly enough, this seems to be the only thing I can't find anything about for this thing.

' It probably has a Peerless transaxle in it and they do make a kit with a filter and fluid with a fill kit. When I was working on landscape equipment about 38 years ago I used John Deere hydraulic oil in all the hydrostatic drives.

Gus

Might try googling White lawn tractors and / or LINKY

If you don't find the answer for the White mower in the "Linky" from TJP they reference the MTD brand for service so I would think whatever MTD recommends should work? Or go with the John Deere brand hydrostatic fluid?

Had a chance to investigate a little more. Choosing the right search terms got me the information. They use 20w50 motor oil.

I had forgotten that White was part of MTD and that information helped locate a filter for half the price I've found elsewhere.

Oddly that link didn't work for me earlier today, seems ok now.

regular hydro fluid could have been a costly mistake

Not sure if it reads 20w50 motor oil for the transmission but for the rear differential in one of the manuals from the link by TJP? Maybe call a local old MTD dealer and see what they recommend?

It does read 20w50 but then has a photo of what looks like to me a differential or is this a hydrostatic transmission??

After a thorough cleaning, to prevent contamination of the fluid, the fill plug can be removedusing a 1/4" allen wrench. See Figure 6.7

Between 5 deg. - 100 deg. f (10 deg. - 38 deg.c), the fluid level should be 1" - 1.25" (2.54cm -3.18cm) from the top of the housing. Total capacity is .600 - .632 gal. (2271ml -2391ml) of 20W-50 motor oil having an API classification of SH/CD.

The transaxle must be removed and inverted to drain the fluid out.

The manual I found was for my specific model and the instructions and drawings match up with what's in the mower.

The regular gear drive transaxle doesn't have a filter or fan or a fill hose..

My old Ariens had a manual gearbox packed with grease.

If you have never changed it you might be better off leaving it alone. I just read a deal from a facebook friend where he changed the hydro fluid in his Kubota tractor that is fairly old. It began to leak from every location it had a seal not to long after that.

It's been changed but not for a few years. In my experience, leaks after an oil change are often from changing to synthetic after using dead dinosaurs.

And I'd rather replace seals than a whole transaxle, or realistically a new mower.

Years ago I had a Case 444 garden tractor that was a hydro. Manual recommended motor oil.

I'm sure Case IH wanted a readily available oil to compensate for how much they leak ☺