Driveshaft Fitting

Hi everyone, Help please. I just bought my first boat and decided to fit a new impeller as the the old one was missing a couple of blades. My problem is when taking the driveshaft out of the housing two rubber parts with spline shapes in them fell out. Where on the shaft do they fit and in what order. Any help would be great. Cheers

You would have more luck with an answer if you gave some info like engine brand and year model and post it over on the engine page for your brand.