I have a 1993 (I think) B7100HST 4x4. I recently bought a Bush Hog 1846QT FEL for this tractor. In the installation manual it says that I have to buy a fitting from Kubota p/n 70010-00306. It's basically a fitting that screws into the fill hole for the transmission that allows a return line to be added. Simple enough, only the part is no longer available from Kubota. I called Bush Hog and was basically told that since it was a Kubota part that it wasn't their problem. ???? Has anyone else run into this? Any help would be greatly appreciated.