The recommended fluid is NH Multi G 134 fluid. Although when I recently changed the tranny fluid in my TC 33D, NH has a newer fluid as a replacement. I can't give a name for it but your dealer will have one or the other in stock. Should you consider a fluid and filter change, requiring about 4 gallons, go with one or the other and try not to mix them. Be sure to cut open the filters and examine for any metal. My pto clutch in the TZ 18DA had begun to self destruct requiring a new one and the filter contents tipped me off.