U r correct Delmer..
The head and rotor seizes, which in turn snaps the shaft..
Get the numbers off the name plate on the pump..
I highly recommend Pump Guy and strongly urge you to consider sending it to him. He helped me out with a case dozer injection pump and gave me advice on removal and re-installation that prevented the job from taking twice as long. He turned it around in 1 week and lent me the installation tools. Pump runs flawlessly since rebuild