Shift rod self-disconnects. It is splined shaft. Shouldn't be able to mis-align, either, as one side has a flat spot.
Make sure the water tube is seated properly in the grommet on top of the pump housing. Make sure there's fresh grease in the splines on top of the drive shaft before installing. Use a dab of grease to hold the impeller key in it's flat to make it easier to install the impeller.
