Transmission Fluid Question - (not MOPAR)

[BIGSHCLUNK]

After a long time I'm experiencing a trans issue on my 545B Fiat-Allis loader. We changed the filter and cleaned the screen. Both of which looked amazingly good for the work this machine does. ANYWAY -my manual says use Fiat-Allis fluid with a C-3 rating. I'm thinking that this is rebranded Allison C-3. Both of which have gone bye and bye long ago. The fluid we drained out looks like tans fluid, but in researching C-3      I've seen posts for 10w motor oil, 30w motor oil and Dextron. Anyone here with any heavy equpt transmission experience? 

[blown motor]

Any equipment brand will tell you to use their brand of oil. I'm no Allis expert but I would think that any good Hydraulic/ transmission fluid would be fine. Does the hydraulic system and transmission use the same oil reservoir? On a tractor the rear end/transmission is the reservoir for the hydraulic system. It's all the same fluid. I expect your loader is the same. I would guess that buying from a farm equipment dealer,  (CaseIH, John Deere, New Holland) might be a little cheaper than from a heavy equipment dealer but price it out. 

[BIGSHCLUNK]

Hydraulic oil is separate. I've a  Fleet Farm  reasonably close by... I'm just afraid the wrong oil could bring the angel of death. 30w motor oil (example) waaaayyyy different than dextron....