The mid mower lift hydraulic cylinder under the tractor floor that lifts the deck was found frozen when attempting to lower for mower reinstall. Seems the cylinder shaft is solid as a rock. The JD listing of parts is difficult to find P/N of this cylinder. The closest I could uncover is BLV10739 which is a kit with other pieces and contains the cylinder. The listing price of this kit is enough to knock you over. This hydraulic cylinder is quite small about 12" hole to hole extended (maybe a bit more, not sure), cylinder portion about 1.5"diameter, ends a bit bigger at 1.75 diameter, and 7" long. It's a welded assembly so repair is not an option.
Even an aftermarket replacement would be ok if made in USA and not china. The original cylinder does not have any markings on it, I suspect not made in USA since it didn't last very long.