john deere 544B transmission

I have a 544B JD i just picked up. The transmission is having some issues, it seems to me like the clutch packs are slipping but as the machine warms up it gets a bit better. The previous owner said that it had no power while trying to fill the bucket.

I do believe that he was using hydraulic oil in the transmission.. does anyone know what the right oil is for this machine?

john deere 544B transmission