Just wondering what specific weight and brand of oil comes in new zt-3400s? The specific mower is a Dixon Ram ultra 61". I know they recommend 20w50 but is that how they come from the factory?
The Hydro Gear service manual recommends 20w/50 conventional motor oil with a minimum SL rating. You can download the pdf from their website (the 2800/3100/3400 one is at the bottom of the page).
Hydro-Gear Service Repair Manuals
When I received my new Toro MX5060 (zt-2800's), the fill / expansion tank was slightly below the cold fill line. Being somewhat paranoid, I called Toro to see what came with it from the factory, since they recommend 20w/50 oil or their proprietary hydro oil. They flat out told me that they didn't know. I was surprised by that answer. I bought a quart of the Toro hydro oil and when I went to put it in, it was a different color. I'm sure that they are compatible, but after 10 hours, I changed the oil and the filters just to make sure. I used Castrol GTX 20w/50 and Hydro Gear filters.
Bruce