Last year when we up graded our combine but keep the same header and we wrecked on of the header drive PTO shafts because of what we are told is too much horsepower. We now have a Star shaped shaft. The wrecked shaft is what is called a Lemon shaft or is round with 2 "tits" or grooves. The shaft galled inside but that part can be cut off than more than enough can be saved. It fits together much tighter than the reciever tube shafts. Does anyone know if the ujoint for a equipment have similar dimentions or if adapter Ujoints are avalible? Not sure what to do about the double cardan.