deutz dx 130

I have a deutz dx 130 that i just got that has been sitting for over 10 years in a shed. It runs very good but sometimes the 4 Wheel drive doesnt engage and the 2 speed poWeshift doesnt Work all of the time i changed the hydaulic filters and it is full of oil in the resevoir that is located above the pto area in the back. Is there any other place for hydraulic oil or is there a valve or something that could stick? thanks

I"ve never been around a DX130 before, but there should be a cap/dipstick on top of the 3-point unit. This is seperate from the trans./rear-end. There is probably a filler cap on one side or the other of the trans.(in front of the rear wheels). If it doesn"t have a sight-glass, fill until you can stick your finger in and touch oil. Most will say that the DX-series trans./rear-ends were junk. They are probably the ones who didn"t change the trans.-filters or research oils before running their mouths.
The manual will call for "Hyd.-oil" for the trans./rear-end. The Deutz factory fluids exceed what is sold here as Hyd.-trans. fluid. CENPECO makes a good oil, but if you don"t have access to this, use a 13:1 mix of Rotella 15W-20 to 80-90 gear oil. And yes, this will be in gallons. This should give you the same viscosity that these tractors were sold with.
As far as the FWD and the Powermatic engaging, I"m pretty sure that it is done electronically Look for wires on the sides and possibly on top of the trans. that may be corroded, broken, or unplugged. Check the continuity of the part that the wires are connected to. They will either be sensors or actuators. Check the fuses at the base of the dash. Check that the buttons have current to and from them.
It"s a start anyway.