what i have found it says the hydraulic fluid reservoir is in the trans. what are these to dip sticks for.
the big one looks like a hydraulic reservoir
The big one in front of the operator station is the hydraulic tank.smaller dipstick beside it is probably the transmission/torque converter and the one under floorboard is the transaxle.
Do I fill the large one with hydraulic fluid
@glennvierra7 , at the Deere Bookstore there is an option to download a free copy of the 310D Operators manual.See link below. https://www.johndeeretechinfo.com/search?p0=model&p0_v=310D&p1=search&p1_v=Omt&pattr=p0,p1 .
And can go to a dealer and see if they have manuals you can look at.
I think the D series still run hydraulic oil but like was mentioned,get the manual.It will be money well spent and tell you what is recommended for the ambient temperature your operating in.
I have a 710D and use Hyguard only in the trans, can run good quality hyd in the hydraulic system, but I run Hyguard there also
Use Hygard in all 3 compartments. That was the factory fill for that machine. That way you only need to stock one fluid. Due note that the reverser and the transaxle are checked with the engine idling.