I would stay with the Dextron. There was some changing of orfices ect. when they went to hydralic oil. Hydralic oil has improved greatly over the years and I think that is the main reason Gleaner made the switch in '97. Not to say that hydralic oil is better now than Dextron but it is more common with the oils used in your other equipment. I know there are people that have switched oils without a problem but it wouldn't be me. Maybe check with the guy that did switch to see if they flushed system or changed anything else before making a switch.