New LH Transmission for Zero Turn Mowers. New Hydro-Gear LH Transmission Replacement for. Cub Cadet & MTD Part Numbers. The axle shaft on this unit is made for the “Double D” wheel hub. Most mowers have this style, but if you have an earlier unit, it may have a smaller hub and it will not work on this transaxle and you will have to replace the hub with the new style to make it work on your mower. I have the new style hub in stock, just check in our store and type in the part number listed below. Unit is filled with oil and ready to go. Ordered wrong item or not needed, would qualify for a return. If the new pump has been filled with oil or has been installed or has been used in any way, it is non-returnable. Note: It is important to replace the oil and oil filters and flush the hydraulic system before replacing the pump. The new pump must be filled with oil prior to installing and starting up. Purging instructions are included and are very important to follow to ensure the best performance of your new pump.